1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Generic PPP layer for Linux. 4 * 5 * Copyright 1999-2002 Paul Mackerras. 6 * 7 * The generic PPP layer handles the PPP network interfaces, the 8 * /dev/ppp device, packet and VJ compression, and multilink. 9 * It talks to PPP `channels' via the interface defined in 10 * include/linux/ppp_channel.h. Channels provide the basic means for 11 * sending and receiving PPP frames on some kind of communications 12 * channel. 13 * 14 * Part of the code in this driver was inspired by the old async-only 15 * PPP driver, written by Michael Callahan and Al Longyear, and 16 * subsequently hacked by Paul Mackerras. 17 * 18 * ==FILEVERSION 20041108== 19 */ 20 21 #include <linux/module.h> 22 #include <linux/kernel.h> 23 #include <linux/sched/signal.h> 24 #include <linux/kmod.h> 25 #include <linux/init.h> 26 #include <linux/list.h> 27 #include <linux/idr.h> 28 #include <linux/netdevice.h> 29 #include <linux/poll.h> 30 #include <linux/ppp_defs.h> 31 #include <linux/filter.h> 32 #include <linux/ppp-ioctl.h> 33 #include <linux/ppp_channel.h> 34 #include <linux/ppp-comp.h> 35 #include <linux/skbuff.h> 36 #include <linux/rtnetlink.h> 37 #include <linux/if_arp.h> 38 #include <linux/ip.h> 39 #include <linux/tcp.h> 40 #include <linux/spinlock.h> 41 #include <linux/rwsem.h> 42 #include <linux/stddef.h> 43 #include <linux/device.h> 44 #include <linux/mutex.h> 45 #include <linux/slab.h> 46 #include <linux/file.h> 47 #include <asm/unaligned.h> 48 #include <net/slhc_vj.h> 49 #include <linux/atomic.h> 50 #include <linux/refcount.h> 51 52 #include <linux/nsproxy.h> 53 #include <net/net_namespace.h> 54 #include <net/netns/generic.h> 55 56 #define PPP_VERSION "2.4.2" 57 58 /* 59 * Network protocols we support. 60 */ 61 #define NP_IP 0 /* Internet Protocol V4 */ 62 #define NP_IPV6 1 /* Internet Protocol V6 */ 63 #define NP_IPX 2 /* IPX protocol */ 64 #define NP_AT 3 /* Appletalk protocol */ 65 #define NP_MPLS_UC 4 /* MPLS unicast */ 66 #define NP_MPLS_MC 5 /* MPLS multicast */ 67 #define NUM_NP 6 /* Number of NPs. */ 68 69 #define MPHDRLEN 6 /* multilink protocol header length */ 70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 71 72 #define PPP_PROTO_LEN 2 73 74 /* 75 * An instance of /dev/ppp can be associated with either a ppp 76 * interface unit or a ppp channel. In both cases, file->private_data 77 * points to one of these. 78 */ 79 struct ppp_file { 80 enum { 81 INTERFACE=1, CHANNEL 82 } kind; 83 struct sk_buff_head xq; /* pppd transmit queue */ 84 struct sk_buff_head rq; /* receive queue for pppd */ 85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 86 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 87 int hdrlen; /* space to leave for headers */ 88 int index; /* interface unit / channel number */ 89 int dead; /* unit/channel has been shut down */ 90 }; 91 92 #define PF_TO_X(pf, X) container_of(pf, X, file) 93 94 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 95 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 96 97 /* 98 * Data structure to hold primary network stats for which 99 * we want to use 64 bit storage. Other network stats 100 * are stored in dev->stats of the ppp strucute. 101 */ 102 struct ppp_link_stats { 103 u64 rx_packets; 104 u64 tx_packets; 105 u64 rx_bytes; 106 u64 tx_bytes; 107 }; 108 109 /* 110 * Data structure describing one ppp unit. 111 * A ppp unit corresponds to a ppp network interface device 112 * and represents a multilink bundle. 113 * It can have 0 or more ppp channels connected to it. 114 */ 115 struct ppp { 116 struct ppp_file file; /* stuff for read/write/poll 0 */ 117 struct file *owner; /* file that owns this unit 48 */ 118 struct list_head channels; /* list of attached channels 4c */ 119 int n_channels; /* how many channels are attached 54 */ 120 spinlock_t rlock; /* lock for receive side 58 */ 121 spinlock_t wlock; /* lock for transmit side 5c */ 122 int __percpu *xmit_recursion; /* xmit recursion detect */ 123 int mru; /* max receive unit 60 */ 124 unsigned int flags; /* control bits 64 */ 125 unsigned int xstate; /* transmit state bits 68 */ 126 unsigned int rstate; /* receive state bits 6c */ 127 int debug; /* debug flags 70 */ 128 struct slcompress *vj; /* state for VJ header compression */ 129 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 130 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 131 struct compressor *xcomp; /* transmit packet compressor 8c */ 132 void *xc_state; /* its internal state 90 */ 133 struct compressor *rcomp; /* receive decompressor 94 */ 134 void *rc_state; /* its internal state 98 */ 135 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 136 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 137 struct net_device *dev; /* network interface device a4 */ 138 int closing; /* is device closing down? a8 */ 139 #ifdef CONFIG_PPP_MULTILINK 140 int nxchan; /* next channel to send something on */ 141 u32 nxseq; /* next sequence number to send */ 142 int mrru; /* MP: max reconst. receive unit */ 143 u32 nextseq; /* MP: seq no of next packet */ 144 u32 minseq; /* MP: min of most recent seqnos */ 145 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 146 #endif /* CONFIG_PPP_MULTILINK */ 147 #ifdef CONFIG_PPP_FILTER 148 struct bpf_prog *pass_filter; /* filter for packets to pass */ 149 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 150 #endif /* CONFIG_PPP_FILTER */ 151 struct net *ppp_net; /* the net we belong to */ 152 struct ppp_link_stats stats64; /* 64 bit network stats */ 153 }; 154 155 /* 156 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 157 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 158 * SC_MUST_COMP 159 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 160 * Bits in xstate: SC_COMP_RUN 161 */ 162 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 163 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 164 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 165 166 /* 167 * Private data structure for each channel. 168 * This includes the data structure used for multilink. 169 */ 170 struct channel { 171 struct ppp_file file; /* stuff for read/write/poll */ 172 struct list_head list; /* link in all/new_channels list */ 173 struct ppp_channel *chan; /* public channel data structure */ 174 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 175 spinlock_t downl; /* protects `chan', file.xq dequeue */ 176 struct ppp *ppp; /* ppp unit we're connected to */ 177 struct net *chan_net; /* the net channel belongs to */ 178 struct list_head clist; /* link in list of channels per unit */ 179 rwlock_t upl; /* protects `ppp' and 'bridge' */ 180 struct channel __rcu *bridge; /* "bridged" ppp channel */ 181 #ifdef CONFIG_PPP_MULTILINK 182 u8 avail; /* flag used in multilink stuff */ 183 u8 had_frag; /* >= 1 fragments have been sent */ 184 u32 lastseq; /* MP: last sequence # received */ 185 int speed; /* speed of the corresponding ppp channel*/ 186 #endif /* CONFIG_PPP_MULTILINK */ 187 }; 188 189 struct ppp_config { 190 struct file *file; 191 s32 unit; 192 bool ifname_is_set; 193 }; 194 195 /* 196 * SMP locking issues: 197 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 198 * list and the ppp.n_channels field, you need to take both locks 199 * before you modify them. 200 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 201 * channel.downl. 202 */ 203 204 static DEFINE_MUTEX(ppp_mutex); 205 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 206 static atomic_t channel_count = ATOMIC_INIT(0); 207 208 /* per-net private data for this module */ 209 static unsigned int ppp_net_id __read_mostly; 210 struct ppp_net { 211 /* units to ppp mapping */ 212 struct idr units_idr; 213 214 /* 215 * all_ppp_mutex protects the units_idr mapping. 216 * It also ensures that finding a ppp unit in the units_idr 217 * map and updating its file.refcnt field is atomic. 218 */ 219 struct mutex all_ppp_mutex; 220 221 /* channels */ 222 struct list_head all_channels; 223 struct list_head new_channels; 224 int last_channel_index; 225 226 /* 227 * all_channels_lock protects all_channels and 228 * last_channel_index, and the atomicity of find 229 * a channel and updating its file.refcnt field. 230 */ 231 spinlock_t all_channels_lock; 232 }; 233 234 /* Get the PPP protocol number from a skb */ 235 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 236 237 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 238 #define PPP_MAX_RQLEN 32 239 240 /* 241 * Maximum number of multilink fragments queued up. 242 * This has to be large enough to cope with the maximum latency of 243 * the slowest channel relative to the others. Strictly it should 244 * depend on the number of channels and their characteristics. 245 */ 246 #define PPP_MP_MAX_QLEN 128 247 248 /* Multilink header bits. */ 249 #define B 0x80 /* this fragment begins a packet */ 250 #define E 0x40 /* this fragment ends a packet */ 251 252 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 253 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 254 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 255 256 /* Prototypes. */ 257 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 258 struct file *file, unsigned int cmd, unsigned long arg); 259 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 260 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 261 static void ppp_push(struct ppp *ppp); 262 static void ppp_channel_push(struct channel *pch); 263 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 264 struct channel *pch); 265 static void ppp_receive_error(struct ppp *ppp); 266 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 267 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 268 struct sk_buff *skb); 269 #ifdef CONFIG_PPP_MULTILINK 270 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 271 struct channel *pch); 272 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 273 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 274 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 275 #endif /* CONFIG_PPP_MULTILINK */ 276 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data); 277 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 278 static void ppp_ccp_closed(struct ppp *ppp); 279 static struct compressor *find_compressor(int type); 280 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 281 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 282 static void init_ppp_file(struct ppp_file *pf, int kind); 283 static void ppp_destroy_interface(struct ppp *ppp); 284 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 285 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 286 static int ppp_connect_channel(struct channel *pch, int unit); 287 static int ppp_disconnect_channel(struct channel *pch); 288 static void ppp_destroy_channel(struct channel *pch); 289 static int unit_get(struct idr *p, void *ptr, int min); 290 static int unit_set(struct idr *p, void *ptr, int n); 291 static void unit_put(struct idr *p, int n); 292 static void *unit_find(struct idr *p, int n); 293 static void ppp_setup(struct net_device *dev); 294 295 static const struct net_device_ops ppp_netdev_ops; 296 297 static struct class *ppp_class; 298 299 /* per net-namespace data */ 300 static inline struct ppp_net *ppp_pernet(struct net *net) 301 { 302 return net_generic(net, ppp_net_id); 303 } 304 305 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 306 static inline int proto_to_npindex(int proto) 307 { 308 switch (proto) { 309 case PPP_IP: 310 return NP_IP; 311 case PPP_IPV6: 312 return NP_IPV6; 313 case PPP_IPX: 314 return NP_IPX; 315 case PPP_AT: 316 return NP_AT; 317 case PPP_MPLS_UC: 318 return NP_MPLS_UC; 319 case PPP_MPLS_MC: 320 return NP_MPLS_MC; 321 } 322 return -EINVAL; 323 } 324 325 /* Translates an NP index into a PPP protocol number */ 326 static const int npindex_to_proto[NUM_NP] = { 327 PPP_IP, 328 PPP_IPV6, 329 PPP_IPX, 330 PPP_AT, 331 PPP_MPLS_UC, 332 PPP_MPLS_MC, 333 }; 334 335 /* Translates an ethertype into an NP index */ 336 static inline int ethertype_to_npindex(int ethertype) 337 { 338 switch (ethertype) { 339 case ETH_P_IP: 340 return NP_IP; 341 case ETH_P_IPV6: 342 return NP_IPV6; 343 case ETH_P_IPX: 344 return NP_IPX; 345 case ETH_P_PPPTALK: 346 case ETH_P_ATALK: 347 return NP_AT; 348 case ETH_P_MPLS_UC: 349 return NP_MPLS_UC; 350 case ETH_P_MPLS_MC: 351 return NP_MPLS_MC; 352 } 353 return -1; 354 } 355 356 /* Translates an NP index into an ethertype */ 357 static const int npindex_to_ethertype[NUM_NP] = { 358 ETH_P_IP, 359 ETH_P_IPV6, 360 ETH_P_IPX, 361 ETH_P_PPPTALK, 362 ETH_P_MPLS_UC, 363 ETH_P_MPLS_MC, 364 }; 365 366 /* 367 * Locking shorthand. 368 */ 369 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 370 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 371 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 372 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 373 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 374 ppp_recv_lock(ppp); } while (0) 375 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 376 ppp_xmit_unlock(ppp); } while (0) 377 378 /* 379 * /dev/ppp device routines. 380 * The /dev/ppp device is used by pppd to control the ppp unit. 381 * It supports the read, write, ioctl and poll functions. 382 * Open instances of /dev/ppp can be in one of three states: 383 * unattached, attached to a ppp unit, or attached to a ppp channel. 384 */ 385 static int ppp_open(struct inode *inode, struct file *file) 386 { 387 /* 388 * This could (should?) be enforced by the permissions on /dev/ppp. 389 */ 390 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 391 return -EPERM; 392 return 0; 393 } 394 395 static int ppp_release(struct inode *unused, struct file *file) 396 { 397 struct ppp_file *pf = file->private_data; 398 struct ppp *ppp; 399 400 if (pf) { 401 file->private_data = NULL; 402 if (pf->kind == INTERFACE) { 403 ppp = PF_TO_PPP(pf); 404 rtnl_lock(); 405 if (file == ppp->owner) 406 unregister_netdevice(ppp->dev); 407 rtnl_unlock(); 408 } 409 if (refcount_dec_and_test(&pf->refcnt)) { 410 switch (pf->kind) { 411 case INTERFACE: 412 ppp_destroy_interface(PF_TO_PPP(pf)); 413 break; 414 case CHANNEL: 415 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 416 break; 417 } 418 } 419 } 420 return 0; 421 } 422 423 static ssize_t ppp_read(struct file *file, char __user *buf, 424 size_t count, loff_t *ppos) 425 { 426 struct ppp_file *pf = file->private_data; 427 DECLARE_WAITQUEUE(wait, current); 428 ssize_t ret; 429 struct sk_buff *skb = NULL; 430 struct iovec iov; 431 struct iov_iter to; 432 433 ret = count; 434 435 if (!pf) 436 return -ENXIO; 437 add_wait_queue(&pf->rwait, &wait); 438 for (;;) { 439 set_current_state(TASK_INTERRUPTIBLE); 440 skb = skb_dequeue(&pf->rq); 441 if (skb) 442 break; 443 ret = 0; 444 if (pf->dead) 445 break; 446 if (pf->kind == INTERFACE) { 447 /* 448 * Return 0 (EOF) on an interface that has no 449 * channels connected, unless it is looping 450 * network traffic (demand mode). 451 */ 452 struct ppp *ppp = PF_TO_PPP(pf); 453 454 ppp_recv_lock(ppp); 455 if (ppp->n_channels == 0 && 456 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 457 ppp_recv_unlock(ppp); 458 break; 459 } 460 ppp_recv_unlock(ppp); 461 } 462 ret = -EAGAIN; 463 if (file->f_flags & O_NONBLOCK) 464 break; 465 ret = -ERESTARTSYS; 466 if (signal_pending(current)) 467 break; 468 schedule(); 469 } 470 set_current_state(TASK_RUNNING); 471 remove_wait_queue(&pf->rwait, &wait); 472 473 if (!skb) 474 goto out; 475 476 ret = -EOVERFLOW; 477 if (skb->len > count) 478 goto outf; 479 ret = -EFAULT; 480 iov.iov_base = buf; 481 iov.iov_len = count; 482 iov_iter_init(&to, READ, &iov, 1, count); 483 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 484 goto outf; 485 ret = skb->len; 486 487 outf: 488 kfree_skb(skb); 489 out: 490 return ret; 491 } 492 493 static ssize_t ppp_write(struct file *file, const char __user *buf, 494 size_t count, loff_t *ppos) 495 { 496 struct ppp_file *pf = file->private_data; 497 struct sk_buff *skb; 498 ssize_t ret; 499 500 if (!pf) 501 return -ENXIO; 502 /* All PPP packets should start with the 2-byte protocol */ 503 if (count < PPP_PROTO_LEN) 504 return -EINVAL; 505 ret = -ENOMEM; 506 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 507 if (!skb) 508 goto out; 509 skb_reserve(skb, pf->hdrlen); 510 ret = -EFAULT; 511 if (copy_from_user(skb_put(skb, count), buf, count)) { 512 kfree_skb(skb); 513 goto out; 514 } 515 516 switch (pf->kind) { 517 case INTERFACE: 518 ppp_xmit_process(PF_TO_PPP(pf), skb); 519 break; 520 case CHANNEL: 521 skb_queue_tail(&pf->xq, skb); 522 ppp_channel_push(PF_TO_CHANNEL(pf)); 523 break; 524 } 525 526 ret = count; 527 528 out: 529 return ret; 530 } 531 532 /* No kernel lock - fine */ 533 static __poll_t ppp_poll(struct file *file, poll_table *wait) 534 { 535 struct ppp_file *pf = file->private_data; 536 __poll_t mask; 537 538 if (!pf) 539 return 0; 540 poll_wait(file, &pf->rwait, wait); 541 mask = EPOLLOUT | EPOLLWRNORM; 542 if (skb_peek(&pf->rq)) 543 mask |= EPOLLIN | EPOLLRDNORM; 544 if (pf->dead) 545 mask |= EPOLLHUP; 546 else if (pf->kind == INTERFACE) { 547 /* see comment in ppp_read */ 548 struct ppp *ppp = PF_TO_PPP(pf); 549 550 ppp_recv_lock(ppp); 551 if (ppp->n_channels == 0 && 552 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 553 mask |= EPOLLIN | EPOLLRDNORM; 554 ppp_recv_unlock(ppp); 555 } 556 557 return mask; 558 } 559 560 #ifdef CONFIG_PPP_FILTER 561 static struct bpf_prog *get_filter(struct sock_fprog *uprog) 562 { 563 struct sock_fprog_kern fprog; 564 struct bpf_prog *res = NULL; 565 int err; 566 567 if (!uprog->len) 568 return NULL; 569 570 /* uprog->len is unsigned short, so no overflow here */ 571 fprog.len = uprog->len; 572 fprog.filter = memdup_user(uprog->filter, 573 uprog->len * sizeof(struct sock_filter)); 574 if (IS_ERR(fprog.filter)) 575 return ERR_CAST(fprog.filter); 576 577 err = bpf_prog_create(&res, &fprog); 578 kfree(fprog.filter); 579 580 return err ? ERR_PTR(err) : res; 581 } 582 583 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p) 584 { 585 struct sock_fprog uprog; 586 587 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog))) 588 return ERR_PTR(-EFAULT); 589 return get_filter(&uprog); 590 } 591 592 #ifdef CONFIG_COMPAT 593 struct sock_fprog32 { 594 unsigned short len; 595 compat_caddr_t filter; 596 }; 597 598 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32) 599 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32) 600 601 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) 602 { 603 struct sock_fprog32 uprog32; 604 struct sock_fprog uprog; 605 606 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32))) 607 return ERR_PTR(-EFAULT); 608 uprog.len = uprog32.len; 609 uprog.filter = compat_ptr(uprog32.filter); 610 return get_filter(&uprog); 611 } 612 #endif 613 #endif 614 615 /* Bridge one PPP channel to another. 616 * When two channels are bridged, ppp_input on one channel is redirected to 617 * the other's ops->start_xmit handler. 618 * In order to safely bridge channels we must reject channels which are already 619 * part of a bridge instance, or which form part of an existing unit. 620 * Once successfully bridged, each channel holds a reference on the other 621 * to prevent it being freed while the bridge is extant. 622 */ 623 static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) 624 { 625 write_lock_bh(&pch->upl); 626 if (pch->ppp || 627 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) { 628 write_unlock_bh(&pch->upl); 629 return -EALREADY; 630 } 631 refcount_inc(&pchb->file.refcnt); 632 rcu_assign_pointer(pch->bridge, pchb); 633 write_unlock_bh(&pch->upl); 634 635 write_lock_bh(&pchb->upl); 636 if (pchb->ppp || 637 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) { 638 write_unlock_bh(&pchb->upl); 639 goto err_unset; 640 } 641 refcount_inc(&pch->file.refcnt); 642 rcu_assign_pointer(pchb->bridge, pch); 643 write_unlock_bh(&pchb->upl); 644 645 return 0; 646 647 err_unset: 648 write_lock_bh(&pch->upl); 649 /* Re-read pch->bridge with upl held in case it was modified concurrently */ 650 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 651 RCU_INIT_POINTER(pch->bridge, NULL); 652 write_unlock_bh(&pch->upl); 653 synchronize_rcu(); 654 655 if (pchb) 656 if (refcount_dec_and_test(&pchb->file.refcnt)) 657 ppp_destroy_channel(pchb); 658 659 return -EALREADY; 660 } 661 662 static int ppp_unbridge_channels(struct channel *pch) 663 { 664 struct channel *pchb, *pchbb; 665 666 write_lock_bh(&pch->upl); 667 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 668 if (!pchb) { 669 write_unlock_bh(&pch->upl); 670 return -EINVAL; 671 } 672 RCU_INIT_POINTER(pch->bridge, NULL); 673 write_unlock_bh(&pch->upl); 674 675 /* Only modify pchb if phcb->bridge points back to pch. 676 * If not, it implies that there has been a race unbridging (and possibly 677 * even rebridging) pchb. We should leave pchb alone to avoid either a 678 * refcount underflow, or breaking another established bridge instance. 679 */ 680 write_lock_bh(&pchb->upl); 681 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl)); 682 if (pchbb == pch) 683 RCU_INIT_POINTER(pchb->bridge, NULL); 684 write_unlock_bh(&pchb->upl); 685 686 synchronize_rcu(); 687 688 if (pchbb == pch) 689 if (refcount_dec_and_test(&pch->file.refcnt)) 690 ppp_destroy_channel(pch); 691 692 if (refcount_dec_and_test(&pchb->file.refcnt)) 693 ppp_destroy_channel(pchb); 694 695 return 0; 696 } 697 698 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 699 { 700 struct ppp_file *pf; 701 struct ppp *ppp; 702 int err = -EFAULT, val, val2, i; 703 struct ppp_idle32 idle32; 704 struct ppp_idle64 idle64; 705 struct npioctl npi; 706 int unit, cflags; 707 struct slcompress *vj; 708 void __user *argp = (void __user *)arg; 709 int __user *p = argp; 710 711 mutex_lock(&ppp_mutex); 712 713 pf = file->private_data; 714 if (!pf) { 715 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 716 pf, file, cmd, arg); 717 goto out; 718 } 719 720 if (cmd == PPPIOCDETACH) { 721 /* 722 * PPPIOCDETACH is no longer supported as it was heavily broken, 723 * and is only known to have been used by pppd older than 724 * ppp-2.4.2 (released November 2003). 725 */ 726 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 727 current->comm, current->pid); 728 err = -EINVAL; 729 goto out; 730 } 731 732 if (pf->kind == CHANNEL) { 733 struct channel *pch, *pchb; 734 struct ppp_channel *chan; 735 struct ppp_net *pn; 736 737 pch = PF_TO_CHANNEL(pf); 738 739 switch (cmd) { 740 case PPPIOCCONNECT: 741 if (get_user(unit, p)) 742 break; 743 err = ppp_connect_channel(pch, unit); 744 break; 745 746 case PPPIOCDISCONN: 747 err = ppp_disconnect_channel(pch); 748 break; 749 750 case PPPIOCBRIDGECHAN: 751 if (get_user(unit, p)) 752 break; 753 err = -ENXIO; 754 pn = ppp_pernet(current->nsproxy->net_ns); 755 spin_lock_bh(&pn->all_channels_lock); 756 pchb = ppp_find_channel(pn, unit); 757 /* Hold a reference to prevent pchb being freed while 758 * we establish the bridge. 759 */ 760 if (pchb) 761 refcount_inc(&pchb->file.refcnt); 762 spin_unlock_bh(&pn->all_channels_lock); 763 if (!pchb) 764 break; 765 err = ppp_bridge_channels(pch, pchb); 766 /* Drop earlier refcount now bridge establishment is complete */ 767 if (refcount_dec_and_test(&pchb->file.refcnt)) 768 ppp_destroy_channel(pchb); 769 break; 770 771 case PPPIOCUNBRIDGECHAN: 772 err = ppp_unbridge_channels(pch); 773 break; 774 775 default: 776 down_read(&pch->chan_sem); 777 chan = pch->chan; 778 err = -ENOTTY; 779 if (chan && chan->ops->ioctl) 780 err = chan->ops->ioctl(chan, cmd, arg); 781 up_read(&pch->chan_sem); 782 } 783 goto out; 784 } 785 786 if (pf->kind != INTERFACE) { 787 /* can't happen */ 788 pr_err("PPP: not interface or channel??\n"); 789 err = -EINVAL; 790 goto out; 791 } 792 793 ppp = PF_TO_PPP(pf); 794 switch (cmd) { 795 case PPPIOCSMRU: 796 if (get_user(val, p)) 797 break; 798 ppp->mru = val; 799 err = 0; 800 break; 801 802 case PPPIOCSFLAGS: 803 if (get_user(val, p)) 804 break; 805 ppp_lock(ppp); 806 cflags = ppp->flags & ~val; 807 #ifdef CONFIG_PPP_MULTILINK 808 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 809 ppp->nextseq = 0; 810 #endif 811 ppp->flags = val & SC_FLAG_BITS; 812 ppp_unlock(ppp); 813 if (cflags & SC_CCP_OPEN) 814 ppp_ccp_closed(ppp); 815 err = 0; 816 break; 817 818 case PPPIOCGFLAGS: 819 val = ppp->flags | ppp->xstate | ppp->rstate; 820 if (put_user(val, p)) 821 break; 822 err = 0; 823 break; 824 825 case PPPIOCSCOMPRESS: 826 { 827 struct ppp_option_data data; 828 if (copy_from_user(&data, argp, sizeof(data))) 829 err = -EFAULT; 830 else 831 err = ppp_set_compress(ppp, &data); 832 break; 833 } 834 case PPPIOCGUNIT: 835 if (put_user(ppp->file.index, p)) 836 break; 837 err = 0; 838 break; 839 840 case PPPIOCSDEBUG: 841 if (get_user(val, p)) 842 break; 843 ppp->debug = val; 844 err = 0; 845 break; 846 847 case PPPIOCGDEBUG: 848 if (put_user(ppp->debug, p)) 849 break; 850 err = 0; 851 break; 852 853 case PPPIOCGIDLE32: 854 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 855 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; 856 if (copy_to_user(argp, &idle32, sizeof(idle32))) 857 break; 858 err = 0; 859 break; 860 861 case PPPIOCGIDLE64: 862 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 863 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; 864 if (copy_to_user(argp, &idle64, sizeof(idle64))) 865 break; 866 err = 0; 867 break; 868 869 case PPPIOCSMAXCID: 870 if (get_user(val, p)) 871 break; 872 val2 = 15; 873 if ((val >> 16) != 0) { 874 val2 = val >> 16; 875 val &= 0xffff; 876 } 877 vj = slhc_init(val2+1, val+1); 878 if (IS_ERR(vj)) { 879 err = PTR_ERR(vj); 880 break; 881 } 882 ppp_lock(ppp); 883 if (ppp->vj) 884 slhc_free(ppp->vj); 885 ppp->vj = vj; 886 ppp_unlock(ppp); 887 err = 0; 888 break; 889 890 case PPPIOCGNPMODE: 891 case PPPIOCSNPMODE: 892 if (copy_from_user(&npi, argp, sizeof(npi))) 893 break; 894 err = proto_to_npindex(npi.protocol); 895 if (err < 0) 896 break; 897 i = err; 898 if (cmd == PPPIOCGNPMODE) { 899 err = -EFAULT; 900 npi.mode = ppp->npmode[i]; 901 if (copy_to_user(argp, &npi, sizeof(npi))) 902 break; 903 } else { 904 ppp->npmode[i] = npi.mode; 905 /* we may be able to transmit more packets now (??) */ 906 netif_wake_queue(ppp->dev); 907 } 908 err = 0; 909 break; 910 911 #ifdef CONFIG_PPP_FILTER 912 case PPPIOCSPASS: 913 case PPPIOCSACTIVE: 914 { 915 struct bpf_prog *filter = ppp_get_filter(argp); 916 struct bpf_prog **which; 917 918 if (IS_ERR(filter)) { 919 err = PTR_ERR(filter); 920 break; 921 } 922 if (cmd == PPPIOCSPASS) 923 which = &ppp->pass_filter; 924 else 925 which = &ppp->active_filter; 926 ppp_lock(ppp); 927 if (*which) 928 bpf_prog_destroy(*which); 929 *which = filter; 930 ppp_unlock(ppp); 931 err = 0; 932 break; 933 } 934 #endif /* CONFIG_PPP_FILTER */ 935 936 #ifdef CONFIG_PPP_MULTILINK 937 case PPPIOCSMRRU: 938 if (get_user(val, p)) 939 break; 940 ppp_recv_lock(ppp); 941 ppp->mrru = val; 942 ppp_recv_unlock(ppp); 943 err = 0; 944 break; 945 #endif /* CONFIG_PPP_MULTILINK */ 946 947 default: 948 err = -ENOTTY; 949 } 950 951 out: 952 mutex_unlock(&ppp_mutex); 953 954 return err; 955 } 956 957 #ifdef CONFIG_COMPAT 958 struct ppp_option_data32 { 959 compat_uptr_t ptr; 960 u32 length; 961 compat_int_t transmit; 962 }; 963 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) 964 965 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 966 { 967 struct ppp_file *pf; 968 int err = -ENOIOCTLCMD; 969 void __user *argp = (void __user *)arg; 970 971 mutex_lock(&ppp_mutex); 972 973 pf = file->private_data; 974 if (pf && pf->kind == INTERFACE) { 975 struct ppp *ppp = PF_TO_PPP(pf); 976 switch (cmd) { 977 #ifdef CONFIG_PPP_FILTER 978 case PPPIOCSPASS32: 979 case PPPIOCSACTIVE32: 980 { 981 struct bpf_prog *filter = compat_ppp_get_filter(argp); 982 struct bpf_prog **which; 983 984 if (IS_ERR(filter)) { 985 err = PTR_ERR(filter); 986 break; 987 } 988 if (cmd == PPPIOCSPASS32) 989 which = &ppp->pass_filter; 990 else 991 which = &ppp->active_filter; 992 ppp_lock(ppp); 993 if (*which) 994 bpf_prog_destroy(*which); 995 *which = filter; 996 ppp_unlock(ppp); 997 err = 0; 998 break; 999 } 1000 #endif /* CONFIG_PPP_FILTER */ 1001 case PPPIOCSCOMPRESS32: 1002 { 1003 struct ppp_option_data32 data32; 1004 if (copy_from_user(&data32, argp, sizeof(data32))) { 1005 err = -EFAULT; 1006 } else { 1007 struct ppp_option_data data = { 1008 .ptr = compat_ptr(data32.ptr), 1009 .length = data32.length, 1010 .transmit = data32.transmit 1011 }; 1012 err = ppp_set_compress(ppp, &data); 1013 } 1014 break; 1015 } 1016 } 1017 } 1018 mutex_unlock(&ppp_mutex); 1019 1020 /* all other commands have compatible arguments */ 1021 if (err == -ENOIOCTLCMD) 1022 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1023 1024 return err; 1025 } 1026 #endif 1027 1028 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 1029 struct file *file, unsigned int cmd, unsigned long arg) 1030 { 1031 int unit, err = -EFAULT; 1032 struct ppp *ppp; 1033 struct channel *chan; 1034 struct ppp_net *pn; 1035 int __user *p = (int __user *)arg; 1036 1037 switch (cmd) { 1038 case PPPIOCNEWUNIT: 1039 /* Create a new ppp unit */ 1040 if (get_user(unit, p)) 1041 break; 1042 err = ppp_create_interface(net, file, &unit); 1043 if (err < 0) 1044 break; 1045 1046 err = -EFAULT; 1047 if (put_user(unit, p)) 1048 break; 1049 err = 0; 1050 break; 1051 1052 case PPPIOCATTACH: 1053 /* Attach to an existing ppp unit */ 1054 if (get_user(unit, p)) 1055 break; 1056 err = -ENXIO; 1057 pn = ppp_pernet(net); 1058 mutex_lock(&pn->all_ppp_mutex); 1059 ppp = ppp_find_unit(pn, unit); 1060 if (ppp) { 1061 refcount_inc(&ppp->file.refcnt); 1062 file->private_data = &ppp->file; 1063 err = 0; 1064 } 1065 mutex_unlock(&pn->all_ppp_mutex); 1066 break; 1067 1068 case PPPIOCATTCHAN: 1069 if (get_user(unit, p)) 1070 break; 1071 err = -ENXIO; 1072 pn = ppp_pernet(net); 1073 spin_lock_bh(&pn->all_channels_lock); 1074 chan = ppp_find_channel(pn, unit); 1075 if (chan) { 1076 refcount_inc(&chan->file.refcnt); 1077 file->private_data = &chan->file; 1078 err = 0; 1079 } 1080 spin_unlock_bh(&pn->all_channels_lock); 1081 break; 1082 1083 default: 1084 err = -ENOTTY; 1085 } 1086 1087 return err; 1088 } 1089 1090 static const struct file_operations ppp_device_fops = { 1091 .owner = THIS_MODULE, 1092 .read = ppp_read, 1093 .write = ppp_write, 1094 .poll = ppp_poll, 1095 .unlocked_ioctl = ppp_ioctl, 1096 #ifdef CONFIG_COMPAT 1097 .compat_ioctl = ppp_compat_ioctl, 1098 #endif 1099 .open = ppp_open, 1100 .release = ppp_release, 1101 .llseek = noop_llseek, 1102 }; 1103 1104 static __net_init int ppp_init_net(struct net *net) 1105 { 1106 struct ppp_net *pn = net_generic(net, ppp_net_id); 1107 1108 idr_init(&pn->units_idr); 1109 mutex_init(&pn->all_ppp_mutex); 1110 1111 INIT_LIST_HEAD(&pn->all_channels); 1112 INIT_LIST_HEAD(&pn->new_channels); 1113 1114 spin_lock_init(&pn->all_channels_lock); 1115 1116 return 0; 1117 } 1118 1119 static __net_exit void ppp_exit_net(struct net *net) 1120 { 1121 struct ppp_net *pn = net_generic(net, ppp_net_id); 1122 struct net_device *dev; 1123 struct net_device *aux; 1124 struct ppp *ppp; 1125 LIST_HEAD(list); 1126 int id; 1127 1128 rtnl_lock(); 1129 for_each_netdev_safe(net, dev, aux) { 1130 if (dev->netdev_ops == &ppp_netdev_ops) 1131 unregister_netdevice_queue(dev, &list); 1132 } 1133 1134 idr_for_each_entry(&pn->units_idr, ppp, id) 1135 /* Skip devices already unregistered by previous loop */ 1136 if (!net_eq(dev_net(ppp->dev), net)) 1137 unregister_netdevice_queue(ppp->dev, &list); 1138 1139 unregister_netdevice_many(&list); 1140 rtnl_unlock(); 1141 1142 mutex_destroy(&pn->all_ppp_mutex); 1143 idr_destroy(&pn->units_idr); 1144 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 1145 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 1146 } 1147 1148 static struct pernet_operations ppp_net_ops = { 1149 .init = ppp_init_net, 1150 .exit = ppp_exit_net, 1151 .id = &ppp_net_id, 1152 .size = sizeof(struct ppp_net), 1153 }; 1154 1155 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 1156 { 1157 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1158 int ret; 1159 1160 mutex_lock(&pn->all_ppp_mutex); 1161 1162 if (unit < 0) { 1163 ret = unit_get(&pn->units_idr, ppp, 0); 1164 if (ret < 0) 1165 goto err; 1166 if (!ifname_is_set) { 1167 while (1) { 1168 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret); 1169 if (!netdev_name_in_use(ppp->ppp_net, ppp->dev->name)) 1170 break; 1171 unit_put(&pn->units_idr, ret); 1172 ret = unit_get(&pn->units_idr, ppp, ret + 1); 1173 if (ret < 0) 1174 goto err; 1175 } 1176 } 1177 } else { 1178 /* Caller asked for a specific unit number. Fail with -EEXIST 1179 * if unavailable. For backward compatibility, return -EEXIST 1180 * too if idr allocation fails; this makes pppd retry without 1181 * requesting a specific unit number. 1182 */ 1183 if (unit_find(&pn->units_idr, unit)) { 1184 ret = -EEXIST; 1185 goto err; 1186 } 1187 ret = unit_set(&pn->units_idr, ppp, unit); 1188 if (ret < 0) { 1189 /* Rewrite error for backward compatibility */ 1190 ret = -EEXIST; 1191 goto err; 1192 } 1193 } 1194 ppp->file.index = ret; 1195 1196 if (!ifname_is_set) 1197 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1198 1199 mutex_unlock(&pn->all_ppp_mutex); 1200 1201 ret = register_netdevice(ppp->dev); 1202 if (ret < 0) 1203 goto err_unit; 1204 1205 atomic_inc(&ppp_unit_count); 1206 1207 return 0; 1208 1209 err_unit: 1210 mutex_lock(&pn->all_ppp_mutex); 1211 unit_put(&pn->units_idr, ppp->file.index); 1212 err: 1213 mutex_unlock(&pn->all_ppp_mutex); 1214 1215 return ret; 1216 } 1217 1218 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1219 const struct ppp_config *conf) 1220 { 1221 struct ppp *ppp = netdev_priv(dev); 1222 int indx; 1223 int err; 1224 int cpu; 1225 1226 ppp->dev = dev; 1227 ppp->ppp_net = src_net; 1228 ppp->mru = PPP_MRU; 1229 ppp->owner = conf->file; 1230 1231 init_ppp_file(&ppp->file, INTERFACE); 1232 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1233 1234 for (indx = 0; indx < NUM_NP; ++indx) 1235 ppp->npmode[indx] = NPMODE_PASS; 1236 INIT_LIST_HEAD(&ppp->channels); 1237 spin_lock_init(&ppp->rlock); 1238 spin_lock_init(&ppp->wlock); 1239 1240 ppp->xmit_recursion = alloc_percpu(int); 1241 if (!ppp->xmit_recursion) { 1242 err = -ENOMEM; 1243 goto err1; 1244 } 1245 for_each_possible_cpu(cpu) 1246 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1247 1248 #ifdef CONFIG_PPP_MULTILINK 1249 ppp->minseq = -1; 1250 skb_queue_head_init(&ppp->mrq); 1251 #endif /* CONFIG_PPP_MULTILINK */ 1252 #ifdef CONFIG_PPP_FILTER 1253 ppp->pass_filter = NULL; 1254 ppp->active_filter = NULL; 1255 #endif /* CONFIG_PPP_FILTER */ 1256 1257 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1258 if (err < 0) 1259 goto err2; 1260 1261 conf->file->private_data = &ppp->file; 1262 1263 return 0; 1264 err2: 1265 free_percpu(ppp->xmit_recursion); 1266 err1: 1267 return err; 1268 } 1269 1270 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1271 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1272 }; 1273 1274 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1275 struct netlink_ext_ack *extack) 1276 { 1277 if (!data) 1278 return -EINVAL; 1279 1280 if (!data[IFLA_PPP_DEV_FD]) 1281 return -EINVAL; 1282 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1283 return -EBADF; 1284 1285 return 0; 1286 } 1287 1288 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1289 struct nlattr *tb[], struct nlattr *data[], 1290 struct netlink_ext_ack *extack) 1291 { 1292 struct ppp_config conf = { 1293 .unit = -1, 1294 .ifname_is_set = true, 1295 }; 1296 struct file *file; 1297 int err; 1298 1299 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1300 if (!file) 1301 return -EBADF; 1302 1303 /* rtnl_lock is already held here, but ppp_create_interface() locks 1304 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1305 * possible deadlock due to lock order inversion, at the cost of 1306 * pushing the problem back to userspace. 1307 */ 1308 if (!mutex_trylock(&ppp_mutex)) { 1309 err = -EBUSY; 1310 goto out; 1311 } 1312 1313 if (file->f_op != &ppp_device_fops || file->private_data) { 1314 err = -EBADF; 1315 goto out_unlock; 1316 } 1317 1318 conf.file = file; 1319 1320 /* Don't use device name generated by the rtnetlink layer when ifname 1321 * isn't specified. Let ppp_dev_configure() set the device name using 1322 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1323 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1324 */ 1325 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME])) 1326 conf.ifname_is_set = false; 1327 1328 err = ppp_dev_configure(src_net, dev, &conf); 1329 1330 out_unlock: 1331 mutex_unlock(&ppp_mutex); 1332 out: 1333 fput(file); 1334 1335 return err; 1336 } 1337 1338 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1339 { 1340 unregister_netdevice_queue(dev, head); 1341 } 1342 1343 static size_t ppp_nl_get_size(const struct net_device *dev) 1344 { 1345 return 0; 1346 } 1347 1348 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1349 { 1350 return 0; 1351 } 1352 1353 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1354 { 1355 struct ppp *ppp = netdev_priv(dev); 1356 1357 return ppp->ppp_net; 1358 } 1359 1360 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1361 .kind = "ppp", 1362 .maxtype = IFLA_PPP_MAX, 1363 .policy = ppp_nl_policy, 1364 .priv_size = sizeof(struct ppp), 1365 .setup = ppp_setup, 1366 .validate = ppp_nl_validate, 1367 .newlink = ppp_nl_newlink, 1368 .dellink = ppp_nl_dellink, 1369 .get_size = ppp_nl_get_size, 1370 .fill_info = ppp_nl_fill_info, 1371 .get_link_net = ppp_nl_get_link_net, 1372 }; 1373 1374 #define PPP_MAJOR 108 1375 1376 /* Called at boot time if ppp is compiled into the kernel, 1377 or at module load time (from init_module) if compiled as a module. */ 1378 static int __init ppp_init(void) 1379 { 1380 int err; 1381 1382 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1383 1384 err = register_pernet_device(&ppp_net_ops); 1385 if (err) { 1386 pr_err("failed to register PPP pernet device (%d)\n", err); 1387 goto out; 1388 } 1389 1390 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1391 if (err) { 1392 pr_err("failed to register PPP device (%d)\n", err); 1393 goto out_net; 1394 } 1395 1396 ppp_class = class_create(THIS_MODULE, "ppp"); 1397 if (IS_ERR(ppp_class)) { 1398 err = PTR_ERR(ppp_class); 1399 goto out_chrdev; 1400 } 1401 1402 err = rtnl_link_register(&ppp_link_ops); 1403 if (err) { 1404 pr_err("failed to register rtnetlink PPP handler\n"); 1405 goto out_class; 1406 } 1407 1408 /* not a big deal if we fail here :-) */ 1409 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1410 1411 return 0; 1412 1413 out_class: 1414 class_destroy(ppp_class); 1415 out_chrdev: 1416 unregister_chrdev(PPP_MAJOR, "ppp"); 1417 out_net: 1418 unregister_pernet_device(&ppp_net_ops); 1419 out: 1420 return err; 1421 } 1422 1423 /* 1424 * Network interface unit routines. 1425 */ 1426 static netdev_tx_t 1427 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1428 { 1429 struct ppp *ppp = netdev_priv(dev); 1430 int npi, proto; 1431 unsigned char *pp; 1432 1433 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1434 if (npi < 0) 1435 goto outf; 1436 1437 /* Drop, accept or reject the packet */ 1438 switch (ppp->npmode[npi]) { 1439 case NPMODE_PASS: 1440 break; 1441 case NPMODE_QUEUE: 1442 /* it would be nice to have a way to tell the network 1443 system to queue this one up for later. */ 1444 goto outf; 1445 case NPMODE_DROP: 1446 case NPMODE_ERROR: 1447 goto outf; 1448 } 1449 1450 /* Put the 2-byte PPP protocol number on the front, 1451 making sure there is room for the address and control fields. */ 1452 if (skb_cow_head(skb, PPP_HDRLEN)) 1453 goto outf; 1454 1455 pp = skb_push(skb, 2); 1456 proto = npindex_to_proto[npi]; 1457 put_unaligned_be16(proto, pp); 1458 1459 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1460 ppp_xmit_process(ppp, skb); 1461 1462 return NETDEV_TX_OK; 1463 1464 outf: 1465 kfree_skb(skb); 1466 ++dev->stats.tx_dropped; 1467 return NETDEV_TX_OK; 1468 } 1469 1470 static int 1471 ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 1472 void __user *addr, int cmd) 1473 { 1474 struct ppp *ppp = netdev_priv(dev); 1475 int err = -EFAULT; 1476 struct ppp_stats stats; 1477 struct ppp_comp_stats cstats; 1478 char *vers; 1479 1480 switch (cmd) { 1481 case SIOCGPPPSTATS: 1482 ppp_get_stats(ppp, &stats); 1483 if (copy_to_user(addr, &stats, sizeof(stats))) 1484 break; 1485 err = 0; 1486 break; 1487 1488 case SIOCGPPPCSTATS: 1489 memset(&cstats, 0, sizeof(cstats)); 1490 if (ppp->xc_state) 1491 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1492 if (ppp->rc_state) 1493 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1494 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1495 break; 1496 err = 0; 1497 break; 1498 1499 case SIOCGPPPVER: 1500 vers = PPP_VERSION; 1501 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1502 break; 1503 err = 0; 1504 break; 1505 1506 default: 1507 err = -EINVAL; 1508 } 1509 1510 return err; 1511 } 1512 1513 static void 1514 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1515 { 1516 struct ppp *ppp = netdev_priv(dev); 1517 1518 ppp_recv_lock(ppp); 1519 stats64->rx_packets = ppp->stats64.rx_packets; 1520 stats64->rx_bytes = ppp->stats64.rx_bytes; 1521 ppp_recv_unlock(ppp); 1522 1523 ppp_xmit_lock(ppp); 1524 stats64->tx_packets = ppp->stats64.tx_packets; 1525 stats64->tx_bytes = ppp->stats64.tx_bytes; 1526 ppp_xmit_unlock(ppp); 1527 1528 stats64->rx_errors = dev->stats.rx_errors; 1529 stats64->tx_errors = dev->stats.tx_errors; 1530 stats64->rx_dropped = dev->stats.rx_dropped; 1531 stats64->tx_dropped = dev->stats.tx_dropped; 1532 stats64->rx_length_errors = dev->stats.rx_length_errors; 1533 } 1534 1535 static int ppp_dev_init(struct net_device *dev) 1536 { 1537 struct ppp *ppp; 1538 1539 netdev_lockdep_set_classes(dev); 1540 1541 ppp = netdev_priv(dev); 1542 /* Let the netdevice take a reference on the ppp file. This ensures 1543 * that ppp_destroy_interface() won't run before the device gets 1544 * unregistered. 1545 */ 1546 refcount_inc(&ppp->file.refcnt); 1547 1548 return 0; 1549 } 1550 1551 static void ppp_dev_uninit(struct net_device *dev) 1552 { 1553 struct ppp *ppp = netdev_priv(dev); 1554 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1555 1556 ppp_lock(ppp); 1557 ppp->closing = 1; 1558 ppp_unlock(ppp); 1559 1560 mutex_lock(&pn->all_ppp_mutex); 1561 unit_put(&pn->units_idr, ppp->file.index); 1562 mutex_unlock(&pn->all_ppp_mutex); 1563 1564 ppp->owner = NULL; 1565 1566 ppp->file.dead = 1; 1567 wake_up_interruptible(&ppp->file.rwait); 1568 } 1569 1570 static void ppp_dev_priv_destructor(struct net_device *dev) 1571 { 1572 struct ppp *ppp; 1573 1574 ppp = netdev_priv(dev); 1575 if (refcount_dec_and_test(&ppp->file.refcnt)) 1576 ppp_destroy_interface(ppp); 1577 } 1578 1579 static int ppp_fill_forward_path(struct net_device_path_ctx *ctx, 1580 struct net_device_path *path) 1581 { 1582 struct ppp *ppp = netdev_priv(ctx->dev); 1583 struct ppp_channel *chan; 1584 struct channel *pch; 1585 1586 if (ppp->flags & SC_MULTILINK) 1587 return -EOPNOTSUPP; 1588 1589 if (list_empty(&ppp->channels)) 1590 return -ENODEV; 1591 1592 pch = list_first_entry(&ppp->channels, struct channel, clist); 1593 chan = pch->chan; 1594 if (!chan->ops->fill_forward_path) 1595 return -EOPNOTSUPP; 1596 1597 return chan->ops->fill_forward_path(ctx, path, chan); 1598 } 1599 1600 static const struct net_device_ops ppp_netdev_ops = { 1601 .ndo_init = ppp_dev_init, 1602 .ndo_uninit = ppp_dev_uninit, 1603 .ndo_start_xmit = ppp_start_xmit, 1604 .ndo_siocdevprivate = ppp_net_siocdevprivate, 1605 .ndo_get_stats64 = ppp_get_stats64, 1606 .ndo_fill_forward_path = ppp_fill_forward_path, 1607 }; 1608 1609 static struct device_type ppp_type = { 1610 .name = "ppp", 1611 }; 1612 1613 static void ppp_setup(struct net_device *dev) 1614 { 1615 dev->netdev_ops = &ppp_netdev_ops; 1616 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1617 1618 dev->features |= NETIF_F_LLTX; 1619 1620 dev->hard_header_len = PPP_HDRLEN; 1621 dev->mtu = PPP_MRU; 1622 dev->addr_len = 0; 1623 dev->tx_queue_len = 3; 1624 dev->type = ARPHRD_PPP; 1625 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1626 dev->priv_destructor = ppp_dev_priv_destructor; 1627 netif_keep_dst(dev); 1628 } 1629 1630 /* 1631 * Transmit-side routines. 1632 */ 1633 1634 /* Called to do any work queued up on the transmit side that can now be done */ 1635 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1636 { 1637 ppp_xmit_lock(ppp); 1638 if (!ppp->closing) { 1639 ppp_push(ppp); 1640 1641 if (skb) 1642 skb_queue_tail(&ppp->file.xq, skb); 1643 while (!ppp->xmit_pending && 1644 (skb = skb_dequeue(&ppp->file.xq))) 1645 ppp_send_frame(ppp, skb); 1646 /* If there's no work left to do, tell the core net 1647 code that we can accept some more. */ 1648 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1649 netif_wake_queue(ppp->dev); 1650 else 1651 netif_stop_queue(ppp->dev); 1652 } else { 1653 kfree_skb(skb); 1654 } 1655 ppp_xmit_unlock(ppp); 1656 } 1657 1658 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1659 { 1660 local_bh_disable(); 1661 1662 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1663 goto err; 1664 1665 (*this_cpu_ptr(ppp->xmit_recursion))++; 1666 __ppp_xmit_process(ppp, skb); 1667 (*this_cpu_ptr(ppp->xmit_recursion))--; 1668 1669 local_bh_enable(); 1670 1671 return; 1672 1673 err: 1674 local_bh_enable(); 1675 1676 kfree_skb(skb); 1677 1678 if (net_ratelimit()) 1679 netdev_err(ppp->dev, "recursion detected\n"); 1680 } 1681 1682 static inline struct sk_buff * 1683 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1684 { 1685 struct sk_buff *new_skb; 1686 int len; 1687 int new_skb_size = ppp->dev->mtu + 1688 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1689 int compressor_skb_size = ppp->dev->mtu + 1690 ppp->xcomp->comp_extra + PPP_HDRLEN; 1691 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1692 if (!new_skb) { 1693 if (net_ratelimit()) 1694 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1695 return NULL; 1696 } 1697 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1698 skb_reserve(new_skb, 1699 ppp->dev->hard_header_len - PPP_HDRLEN); 1700 1701 /* compressor still expects A/C bytes in hdr */ 1702 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1703 new_skb->data, skb->len + 2, 1704 compressor_skb_size); 1705 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1706 consume_skb(skb); 1707 skb = new_skb; 1708 skb_put(skb, len); 1709 skb_pull(skb, 2); /* pull off A/C bytes */ 1710 } else if (len == 0) { 1711 /* didn't compress, or CCP not up yet */ 1712 consume_skb(new_skb); 1713 new_skb = skb; 1714 } else { 1715 /* 1716 * (len < 0) 1717 * MPPE requires that we do not send unencrypted 1718 * frames. The compressor will return -1 if we 1719 * should drop the frame. We cannot simply test 1720 * the compress_proto because MPPE and MPPC share 1721 * the same number. 1722 */ 1723 if (net_ratelimit()) 1724 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1725 kfree_skb(skb); 1726 consume_skb(new_skb); 1727 new_skb = NULL; 1728 } 1729 return new_skb; 1730 } 1731 1732 /* 1733 * Compress and send a frame. 1734 * The caller should have locked the xmit path, 1735 * and xmit_pending should be 0. 1736 */ 1737 static void 1738 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1739 { 1740 int proto = PPP_PROTO(skb); 1741 struct sk_buff *new_skb; 1742 int len; 1743 unsigned char *cp; 1744 1745 if (proto < 0x8000) { 1746 #ifdef CONFIG_PPP_FILTER 1747 /* check if we should pass this packet */ 1748 /* the filter instructions are constructed assuming 1749 a four-byte PPP header on each packet */ 1750 *(u8 *)skb_push(skb, 2) = 1; 1751 if (ppp->pass_filter && 1752 bpf_prog_run(ppp->pass_filter, skb) == 0) { 1753 if (ppp->debug & 1) 1754 netdev_printk(KERN_DEBUG, ppp->dev, 1755 "PPP: outbound frame " 1756 "not passed\n"); 1757 kfree_skb(skb); 1758 return; 1759 } 1760 /* if this packet passes the active filter, record the time */ 1761 if (!(ppp->active_filter && 1762 bpf_prog_run(ppp->active_filter, skb) == 0)) 1763 ppp->last_xmit = jiffies; 1764 skb_pull(skb, 2); 1765 #else 1766 /* for data packets, record the time */ 1767 ppp->last_xmit = jiffies; 1768 #endif /* CONFIG_PPP_FILTER */ 1769 } 1770 1771 ++ppp->stats64.tx_packets; 1772 ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN; 1773 1774 switch (proto) { 1775 case PPP_IP: 1776 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1777 break; 1778 /* try to do VJ TCP header compression */ 1779 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1780 GFP_ATOMIC); 1781 if (!new_skb) { 1782 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1783 goto drop; 1784 } 1785 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1786 cp = skb->data + 2; 1787 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1788 new_skb->data + 2, &cp, 1789 !(ppp->flags & SC_NO_TCP_CCID)); 1790 if (cp == skb->data + 2) { 1791 /* didn't compress */ 1792 consume_skb(new_skb); 1793 } else { 1794 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1795 proto = PPP_VJC_COMP; 1796 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1797 } else { 1798 proto = PPP_VJC_UNCOMP; 1799 cp[0] = skb->data[2]; 1800 } 1801 consume_skb(skb); 1802 skb = new_skb; 1803 cp = skb_put(skb, len + 2); 1804 cp[0] = 0; 1805 cp[1] = proto; 1806 } 1807 break; 1808 1809 case PPP_CCP: 1810 /* peek at outbound CCP frames */ 1811 ppp_ccp_peek(ppp, skb, 0); 1812 break; 1813 } 1814 1815 /* try to do packet compression */ 1816 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1817 proto != PPP_LCP && proto != PPP_CCP) { 1818 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1819 if (net_ratelimit()) 1820 netdev_err(ppp->dev, 1821 "ppp: compression required but " 1822 "down - pkt dropped.\n"); 1823 goto drop; 1824 } 1825 skb = pad_compress_skb(ppp, skb); 1826 if (!skb) 1827 goto drop; 1828 } 1829 1830 /* 1831 * If we are waiting for traffic (demand dialling), 1832 * queue it up for pppd to receive. 1833 */ 1834 if (ppp->flags & SC_LOOP_TRAFFIC) { 1835 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1836 goto drop; 1837 skb_queue_tail(&ppp->file.rq, skb); 1838 wake_up_interruptible(&ppp->file.rwait); 1839 return; 1840 } 1841 1842 ppp->xmit_pending = skb; 1843 ppp_push(ppp); 1844 return; 1845 1846 drop: 1847 kfree_skb(skb); 1848 ++ppp->dev->stats.tx_errors; 1849 } 1850 1851 /* 1852 * Try to send the frame in xmit_pending. 1853 * The caller should have the xmit path locked. 1854 */ 1855 static void 1856 ppp_push(struct ppp *ppp) 1857 { 1858 struct list_head *list; 1859 struct channel *pch; 1860 struct sk_buff *skb = ppp->xmit_pending; 1861 1862 if (!skb) 1863 return; 1864 1865 list = &ppp->channels; 1866 if (list_empty(list)) { 1867 /* nowhere to send the packet, just drop it */ 1868 ppp->xmit_pending = NULL; 1869 kfree_skb(skb); 1870 return; 1871 } 1872 1873 if ((ppp->flags & SC_MULTILINK) == 0) { 1874 /* not doing multilink: send it down the first channel */ 1875 list = list->next; 1876 pch = list_entry(list, struct channel, clist); 1877 1878 spin_lock(&pch->downl); 1879 if (pch->chan) { 1880 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1881 ppp->xmit_pending = NULL; 1882 } else { 1883 /* channel got unregistered */ 1884 kfree_skb(skb); 1885 ppp->xmit_pending = NULL; 1886 } 1887 spin_unlock(&pch->downl); 1888 return; 1889 } 1890 1891 #ifdef CONFIG_PPP_MULTILINK 1892 /* Multilink: fragment the packet over as many links 1893 as can take the packet at the moment. */ 1894 if (!ppp_mp_explode(ppp, skb)) 1895 return; 1896 #endif /* CONFIG_PPP_MULTILINK */ 1897 1898 ppp->xmit_pending = NULL; 1899 kfree_skb(skb); 1900 } 1901 1902 #ifdef CONFIG_PPP_MULTILINK 1903 static bool mp_protocol_compress __read_mostly = true; 1904 module_param(mp_protocol_compress, bool, 0644); 1905 MODULE_PARM_DESC(mp_protocol_compress, 1906 "compress protocol id in multilink fragments"); 1907 1908 /* 1909 * Divide a packet to be transmitted into fragments and 1910 * send them out the individual links. 1911 */ 1912 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1913 { 1914 int len, totlen; 1915 int i, bits, hdrlen, mtu; 1916 int flen; 1917 int navail, nfree, nzero; 1918 int nbigger; 1919 int totspeed; 1920 int totfree; 1921 unsigned char *p, *q; 1922 struct list_head *list; 1923 struct channel *pch; 1924 struct sk_buff *frag; 1925 struct ppp_channel *chan; 1926 1927 totspeed = 0; /*total bitrate of the bundle*/ 1928 nfree = 0; /* # channels which have no packet already queued */ 1929 navail = 0; /* total # of usable channels (not deregistered) */ 1930 nzero = 0; /* number of channels with zero speed associated*/ 1931 totfree = 0; /*total # of channels available and 1932 *having no queued packets before 1933 *starting the fragmentation*/ 1934 1935 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1936 i = 0; 1937 list_for_each_entry(pch, &ppp->channels, clist) { 1938 if (pch->chan) { 1939 pch->avail = 1; 1940 navail++; 1941 pch->speed = pch->chan->speed; 1942 } else { 1943 pch->avail = 0; 1944 } 1945 if (pch->avail) { 1946 if (skb_queue_empty(&pch->file.xq) || 1947 !pch->had_frag) { 1948 if (pch->speed == 0) 1949 nzero++; 1950 else 1951 totspeed += pch->speed; 1952 1953 pch->avail = 2; 1954 ++nfree; 1955 ++totfree; 1956 } 1957 if (!pch->had_frag && i < ppp->nxchan) 1958 ppp->nxchan = i; 1959 } 1960 ++i; 1961 } 1962 /* 1963 * Don't start sending this packet unless at least half of 1964 * the channels are free. This gives much better TCP 1965 * performance if we have a lot of channels. 1966 */ 1967 if (nfree == 0 || nfree < navail / 2) 1968 return 0; /* can't take now, leave it in xmit_pending */ 1969 1970 /* Do protocol field compression */ 1971 p = skb->data; 1972 len = skb->len; 1973 if (*p == 0 && mp_protocol_compress) { 1974 ++p; 1975 --len; 1976 } 1977 1978 totlen = len; 1979 nbigger = len % nfree; 1980 1981 /* skip to the channel after the one we last used 1982 and start at that one */ 1983 list = &ppp->channels; 1984 for (i = 0; i < ppp->nxchan; ++i) { 1985 list = list->next; 1986 if (list == &ppp->channels) { 1987 i = 0; 1988 break; 1989 } 1990 } 1991 1992 /* create a fragment for each channel */ 1993 bits = B; 1994 while (len > 0) { 1995 list = list->next; 1996 if (list == &ppp->channels) { 1997 i = 0; 1998 continue; 1999 } 2000 pch = list_entry(list, struct channel, clist); 2001 ++i; 2002 if (!pch->avail) 2003 continue; 2004 2005 /* 2006 * Skip this channel if it has a fragment pending already and 2007 * we haven't given a fragment to all of the free channels. 2008 */ 2009 if (pch->avail == 1) { 2010 if (nfree > 0) 2011 continue; 2012 } else { 2013 pch->avail = 1; 2014 } 2015 2016 /* check the channel's mtu and whether it is still attached. */ 2017 spin_lock(&pch->downl); 2018 if (pch->chan == NULL) { 2019 /* can't use this channel, it's being deregistered */ 2020 if (pch->speed == 0) 2021 nzero--; 2022 else 2023 totspeed -= pch->speed; 2024 2025 spin_unlock(&pch->downl); 2026 pch->avail = 0; 2027 totlen = len; 2028 totfree--; 2029 nfree--; 2030 if (--navail == 0) 2031 break; 2032 continue; 2033 } 2034 2035 /* 2036 *if the channel speed is not set divide 2037 *the packet evenly among the free channels; 2038 *otherwise divide it according to the speed 2039 *of the channel we are going to transmit on 2040 */ 2041 flen = len; 2042 if (nfree > 0) { 2043 if (pch->speed == 0) { 2044 flen = len/nfree; 2045 if (nbigger > 0) { 2046 flen++; 2047 nbigger--; 2048 } 2049 } else { 2050 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 2051 ((totspeed*totfree)/pch->speed)) - hdrlen; 2052 if (nbigger > 0) { 2053 flen += ((totfree - nzero)*pch->speed)/totspeed; 2054 nbigger -= ((totfree - nzero)*pch->speed)/ 2055 totspeed; 2056 } 2057 } 2058 nfree--; 2059 } 2060 2061 /* 2062 *check if we are on the last channel or 2063 *we exceded the length of the data to 2064 *fragment 2065 */ 2066 if ((nfree <= 0) || (flen > len)) 2067 flen = len; 2068 /* 2069 *it is not worth to tx on slow channels: 2070 *in that case from the resulting flen according to the 2071 *above formula will be equal or less than zero. 2072 *Skip the channel in this case 2073 */ 2074 if (flen <= 0) { 2075 pch->avail = 2; 2076 spin_unlock(&pch->downl); 2077 continue; 2078 } 2079 2080 /* 2081 * hdrlen includes the 2-byte PPP protocol field, but the 2082 * MTU counts only the payload excluding the protocol field. 2083 * (RFC1661 Section 2) 2084 */ 2085 mtu = pch->chan->mtu - (hdrlen - 2); 2086 if (mtu < 4) 2087 mtu = 4; 2088 if (flen > mtu) 2089 flen = mtu; 2090 if (flen == len) 2091 bits |= E; 2092 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 2093 if (!frag) 2094 goto noskb; 2095 q = skb_put(frag, flen + hdrlen); 2096 2097 /* make the MP header */ 2098 put_unaligned_be16(PPP_MP, q); 2099 if (ppp->flags & SC_MP_XSHORTSEQ) { 2100 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 2101 q[3] = ppp->nxseq; 2102 } else { 2103 q[2] = bits; 2104 q[3] = ppp->nxseq >> 16; 2105 q[4] = ppp->nxseq >> 8; 2106 q[5] = ppp->nxseq; 2107 } 2108 2109 memcpy(q + hdrlen, p, flen); 2110 2111 /* try to send it down the channel */ 2112 chan = pch->chan; 2113 if (!skb_queue_empty(&pch->file.xq) || 2114 !chan->ops->start_xmit(chan, frag)) 2115 skb_queue_tail(&pch->file.xq, frag); 2116 pch->had_frag = 1; 2117 p += flen; 2118 len -= flen; 2119 ++ppp->nxseq; 2120 bits = 0; 2121 spin_unlock(&pch->downl); 2122 } 2123 ppp->nxchan = i; 2124 2125 return 1; 2126 2127 noskb: 2128 spin_unlock(&pch->downl); 2129 if (ppp->debug & 1) 2130 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 2131 ++ppp->dev->stats.tx_errors; 2132 ++ppp->nxseq; 2133 return 1; /* abandon the frame */ 2134 } 2135 #endif /* CONFIG_PPP_MULTILINK */ 2136 2137 /* Try to send data out on a channel */ 2138 static void __ppp_channel_push(struct channel *pch) 2139 { 2140 struct sk_buff *skb; 2141 struct ppp *ppp; 2142 2143 spin_lock(&pch->downl); 2144 if (pch->chan) { 2145 while (!skb_queue_empty(&pch->file.xq)) { 2146 skb = skb_dequeue(&pch->file.xq); 2147 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2148 /* put the packet back and try again later */ 2149 skb_queue_head(&pch->file.xq, skb); 2150 break; 2151 } 2152 } 2153 } else { 2154 /* channel got deregistered */ 2155 skb_queue_purge(&pch->file.xq); 2156 } 2157 spin_unlock(&pch->downl); 2158 /* see if there is anything from the attached unit to be sent */ 2159 if (skb_queue_empty(&pch->file.xq)) { 2160 ppp = pch->ppp; 2161 if (ppp) 2162 __ppp_xmit_process(ppp, NULL); 2163 } 2164 } 2165 2166 static void ppp_channel_push(struct channel *pch) 2167 { 2168 read_lock_bh(&pch->upl); 2169 if (pch->ppp) { 2170 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 2171 __ppp_channel_push(pch); 2172 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 2173 } else { 2174 __ppp_channel_push(pch); 2175 } 2176 read_unlock_bh(&pch->upl); 2177 } 2178 2179 /* 2180 * Receive-side routines. 2181 */ 2182 2183 struct ppp_mp_skb_parm { 2184 u32 sequence; 2185 u8 BEbits; 2186 }; 2187 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2188 2189 static inline void 2190 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2191 { 2192 ppp_recv_lock(ppp); 2193 if (!ppp->closing) 2194 ppp_receive_frame(ppp, skb, pch); 2195 else 2196 kfree_skb(skb); 2197 ppp_recv_unlock(ppp); 2198 } 2199 2200 /** 2201 * __ppp_decompress_proto - Decompress protocol field, slim version. 2202 * @skb: Socket buffer where protocol field should be decompressed. It must have 2203 * at least 1 byte of head room and 1 byte of linear data. First byte of 2204 * data must be a protocol field byte. 2205 * 2206 * Decompress protocol field in PPP header if it's compressed, e.g. when 2207 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2208 * length are done in this function. 2209 */ 2210 static void __ppp_decompress_proto(struct sk_buff *skb) 2211 { 2212 if (skb->data[0] & 0x01) 2213 *(u8 *)skb_push(skb, 1) = 0x00; 2214 } 2215 2216 /** 2217 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2218 * @skb: Socket buffer where protocol field should be decompressed. First byte 2219 * of data must be a protocol field byte. 2220 * 2221 * Decompress protocol field in PPP header if it's compressed, e.g. when 2222 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2223 * sure that skb data room is sufficient for Protocol field, before and after 2224 * decompression. 2225 * 2226 * Return: true - decompressed successfully, false - not enough room in skb. 2227 */ 2228 static bool ppp_decompress_proto(struct sk_buff *skb) 2229 { 2230 /* At least one byte should be present (if protocol is compressed) */ 2231 if (!pskb_may_pull(skb, 1)) 2232 return false; 2233 2234 __ppp_decompress_proto(skb); 2235 2236 /* Protocol field should occupy 2 bytes when not compressed */ 2237 return pskb_may_pull(skb, 2); 2238 } 2239 2240 /* Attempt to handle a frame via. a bridged channel, if one exists. 2241 * If the channel is bridged, the frame is consumed by the bridge. 2242 * If not, the caller must handle the frame by normal recv mechanisms. 2243 * Returns true if the frame is consumed, false otherwise. 2244 */ 2245 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) 2246 { 2247 struct channel *pchb; 2248 2249 rcu_read_lock(); 2250 pchb = rcu_dereference(pch->bridge); 2251 if (!pchb) 2252 goto out_rcu; 2253 2254 spin_lock(&pchb->downl); 2255 if (!pchb->chan) { 2256 /* channel got unregistered */ 2257 kfree_skb(skb); 2258 goto outl; 2259 } 2260 2261 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); 2262 if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) 2263 kfree_skb(skb); 2264 2265 outl: 2266 spin_unlock(&pchb->downl); 2267 out_rcu: 2268 rcu_read_unlock(); 2269 2270 /* If pchb is set then we've consumed the packet */ 2271 return !!pchb; 2272 } 2273 2274 void 2275 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2276 { 2277 struct channel *pch = chan->ppp; 2278 int proto; 2279 2280 if (!pch) { 2281 kfree_skb(skb); 2282 return; 2283 } 2284 2285 /* If the channel is bridged, transmit via. bridge */ 2286 if (ppp_channel_bridge_input(pch, skb)) 2287 return; 2288 2289 read_lock_bh(&pch->upl); 2290 if (!ppp_decompress_proto(skb)) { 2291 kfree_skb(skb); 2292 if (pch->ppp) { 2293 ++pch->ppp->dev->stats.rx_length_errors; 2294 ppp_receive_error(pch->ppp); 2295 } 2296 goto done; 2297 } 2298 2299 proto = PPP_PROTO(skb); 2300 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2301 /* put it on the channel queue */ 2302 skb_queue_tail(&pch->file.rq, skb); 2303 /* drop old frames if queue too long */ 2304 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2305 (skb = skb_dequeue(&pch->file.rq))) 2306 kfree_skb(skb); 2307 wake_up_interruptible(&pch->file.rwait); 2308 } else { 2309 ppp_do_recv(pch->ppp, skb, pch); 2310 } 2311 2312 done: 2313 read_unlock_bh(&pch->upl); 2314 } 2315 2316 /* Put a 0-length skb in the receive queue as an error indication */ 2317 void 2318 ppp_input_error(struct ppp_channel *chan, int code) 2319 { 2320 struct channel *pch = chan->ppp; 2321 struct sk_buff *skb; 2322 2323 if (!pch) 2324 return; 2325 2326 read_lock_bh(&pch->upl); 2327 if (pch->ppp) { 2328 skb = alloc_skb(0, GFP_ATOMIC); 2329 if (skb) { 2330 skb->len = 0; /* probably unnecessary */ 2331 skb->cb[0] = code; 2332 ppp_do_recv(pch->ppp, skb, pch); 2333 } 2334 } 2335 read_unlock_bh(&pch->upl); 2336 } 2337 2338 /* 2339 * We come in here to process a received frame. 2340 * The receive side of the ppp unit is locked. 2341 */ 2342 static void 2343 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2344 { 2345 /* note: a 0-length skb is used as an error indication */ 2346 if (skb->len > 0) { 2347 skb_checksum_complete_unset(skb); 2348 #ifdef CONFIG_PPP_MULTILINK 2349 /* XXX do channel-level decompression here */ 2350 if (PPP_PROTO(skb) == PPP_MP) 2351 ppp_receive_mp_frame(ppp, skb, pch); 2352 else 2353 #endif /* CONFIG_PPP_MULTILINK */ 2354 ppp_receive_nonmp_frame(ppp, skb); 2355 } else { 2356 kfree_skb(skb); 2357 ppp_receive_error(ppp); 2358 } 2359 } 2360 2361 static void 2362 ppp_receive_error(struct ppp *ppp) 2363 { 2364 ++ppp->dev->stats.rx_errors; 2365 if (ppp->vj) 2366 slhc_toss(ppp->vj); 2367 } 2368 2369 static void 2370 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2371 { 2372 struct sk_buff *ns; 2373 int proto, len, npi; 2374 2375 /* 2376 * Decompress the frame, if compressed. 2377 * Note that some decompressors need to see uncompressed frames 2378 * that come in as well as compressed frames. 2379 */ 2380 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2381 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2382 skb = ppp_decompress_frame(ppp, skb); 2383 2384 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2385 goto err; 2386 2387 /* At this point the "Protocol" field MUST be decompressed, either in 2388 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2389 */ 2390 proto = PPP_PROTO(skb); 2391 switch (proto) { 2392 case PPP_VJC_COMP: 2393 /* decompress VJ compressed packets */ 2394 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2395 goto err; 2396 2397 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2398 /* copy to a new sk_buff with more tailroom */ 2399 ns = dev_alloc_skb(skb->len + 128); 2400 if (!ns) { 2401 netdev_err(ppp->dev, "PPP: no memory " 2402 "(VJ decomp)\n"); 2403 goto err; 2404 } 2405 skb_reserve(ns, 2); 2406 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2407 consume_skb(skb); 2408 skb = ns; 2409 } 2410 else 2411 skb->ip_summed = CHECKSUM_NONE; 2412 2413 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2414 if (len <= 0) { 2415 netdev_printk(KERN_DEBUG, ppp->dev, 2416 "PPP: VJ decompression error\n"); 2417 goto err; 2418 } 2419 len += 2; 2420 if (len > skb->len) 2421 skb_put(skb, len - skb->len); 2422 else if (len < skb->len) 2423 skb_trim(skb, len); 2424 proto = PPP_IP; 2425 break; 2426 2427 case PPP_VJC_UNCOMP: 2428 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2429 goto err; 2430 2431 /* Until we fix the decompressor need to make sure 2432 * data portion is linear. 2433 */ 2434 if (!pskb_may_pull(skb, skb->len)) 2435 goto err; 2436 2437 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2438 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2439 goto err; 2440 } 2441 proto = PPP_IP; 2442 break; 2443 2444 case PPP_CCP: 2445 ppp_ccp_peek(ppp, skb, 1); 2446 break; 2447 } 2448 2449 ++ppp->stats64.rx_packets; 2450 ppp->stats64.rx_bytes += skb->len - 2; 2451 2452 npi = proto_to_npindex(proto); 2453 if (npi < 0) { 2454 /* control or unknown frame - pass it to pppd */ 2455 skb_queue_tail(&ppp->file.rq, skb); 2456 /* limit queue length by dropping old frames */ 2457 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2458 (skb = skb_dequeue(&ppp->file.rq))) 2459 kfree_skb(skb); 2460 /* wake up any process polling or blocking on read */ 2461 wake_up_interruptible(&ppp->file.rwait); 2462 2463 } else { 2464 /* network protocol frame - give it to the kernel */ 2465 2466 #ifdef CONFIG_PPP_FILTER 2467 /* check if the packet passes the pass and active filters */ 2468 /* the filter instructions are constructed assuming 2469 a four-byte PPP header on each packet */ 2470 if (ppp->pass_filter || ppp->active_filter) { 2471 if (skb_unclone(skb, GFP_ATOMIC)) 2472 goto err; 2473 2474 *(u8 *)skb_push(skb, 2) = 0; 2475 if (ppp->pass_filter && 2476 bpf_prog_run(ppp->pass_filter, skb) == 0) { 2477 if (ppp->debug & 1) 2478 netdev_printk(KERN_DEBUG, ppp->dev, 2479 "PPP: inbound frame " 2480 "not passed\n"); 2481 kfree_skb(skb); 2482 return; 2483 } 2484 if (!(ppp->active_filter && 2485 bpf_prog_run(ppp->active_filter, skb) == 0)) 2486 ppp->last_recv = jiffies; 2487 __skb_pull(skb, 2); 2488 } else 2489 #endif /* CONFIG_PPP_FILTER */ 2490 ppp->last_recv = jiffies; 2491 2492 if ((ppp->dev->flags & IFF_UP) == 0 || 2493 ppp->npmode[npi] != NPMODE_PASS) { 2494 kfree_skb(skb); 2495 } else { 2496 /* chop off protocol */ 2497 skb_pull_rcsum(skb, 2); 2498 skb->dev = ppp->dev; 2499 skb->protocol = htons(npindex_to_ethertype[npi]); 2500 skb_reset_mac_header(skb); 2501 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2502 dev_net(ppp->dev))); 2503 netif_rx(skb); 2504 } 2505 } 2506 return; 2507 2508 err: 2509 kfree_skb(skb); 2510 ppp_receive_error(ppp); 2511 } 2512 2513 static struct sk_buff * 2514 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2515 { 2516 int proto = PPP_PROTO(skb); 2517 struct sk_buff *ns; 2518 int len; 2519 2520 /* Until we fix all the decompressor's need to make sure 2521 * data portion is linear. 2522 */ 2523 if (!pskb_may_pull(skb, skb->len)) 2524 goto err; 2525 2526 if (proto == PPP_COMP) { 2527 int obuff_size; 2528 2529 switch(ppp->rcomp->compress_proto) { 2530 case CI_MPPE: 2531 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2532 break; 2533 default: 2534 obuff_size = ppp->mru + PPP_HDRLEN; 2535 break; 2536 } 2537 2538 ns = dev_alloc_skb(obuff_size); 2539 if (!ns) { 2540 netdev_err(ppp->dev, "ppp_decompress_frame: " 2541 "no memory\n"); 2542 goto err; 2543 } 2544 /* the decompressor still expects the A/C bytes in the hdr */ 2545 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2546 skb->len + 2, ns->data, obuff_size); 2547 if (len < 0) { 2548 /* Pass the compressed frame to pppd as an 2549 error indication. */ 2550 if (len == DECOMP_FATALERROR) 2551 ppp->rstate |= SC_DC_FERROR; 2552 kfree_skb(ns); 2553 goto err; 2554 } 2555 2556 consume_skb(skb); 2557 skb = ns; 2558 skb_put(skb, len); 2559 skb_pull(skb, 2); /* pull off the A/C bytes */ 2560 2561 /* Don't call __ppp_decompress_proto() here, but instead rely on 2562 * corresponding algo (mppe/bsd/deflate) to decompress it. 2563 */ 2564 } else { 2565 /* Uncompressed frame - pass to decompressor so it 2566 can update its dictionary if necessary. */ 2567 if (ppp->rcomp->incomp) 2568 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2569 skb->len + 2); 2570 } 2571 2572 return skb; 2573 2574 err: 2575 ppp->rstate |= SC_DC_ERROR; 2576 ppp_receive_error(ppp); 2577 return skb; 2578 } 2579 2580 #ifdef CONFIG_PPP_MULTILINK 2581 /* 2582 * Receive a multilink frame. 2583 * We put it on the reconstruction queue and then pull off 2584 * as many completed frames as we can. 2585 */ 2586 static void 2587 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2588 { 2589 u32 mask, seq; 2590 struct channel *ch; 2591 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2592 2593 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2594 goto err; /* no good, throw it away */ 2595 2596 /* Decode sequence number and begin/end bits */ 2597 if (ppp->flags & SC_MP_SHORTSEQ) { 2598 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2599 mask = 0xfff; 2600 } else { 2601 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2602 mask = 0xffffff; 2603 } 2604 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2605 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2606 2607 /* 2608 * Do protocol ID decompression on the first fragment of each packet. 2609 * We have to do that here, because ppp_receive_nonmp_frame() expects 2610 * decompressed protocol field. 2611 */ 2612 if (PPP_MP_CB(skb)->BEbits & B) 2613 __ppp_decompress_proto(skb); 2614 2615 /* 2616 * Expand sequence number to 32 bits, making it as close 2617 * as possible to ppp->minseq. 2618 */ 2619 seq |= ppp->minseq & ~mask; 2620 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2621 seq += mask + 1; 2622 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2623 seq -= mask + 1; /* should never happen */ 2624 PPP_MP_CB(skb)->sequence = seq; 2625 pch->lastseq = seq; 2626 2627 /* 2628 * If this packet comes before the next one we were expecting, 2629 * drop it. 2630 */ 2631 if (seq_before(seq, ppp->nextseq)) { 2632 kfree_skb(skb); 2633 ++ppp->dev->stats.rx_dropped; 2634 ppp_receive_error(ppp); 2635 return; 2636 } 2637 2638 /* 2639 * Reevaluate minseq, the minimum over all channels of the 2640 * last sequence number received on each channel. Because of 2641 * the increasing sequence number rule, we know that any fragment 2642 * before `minseq' which hasn't arrived is never going to arrive. 2643 * The list of channels can't change because we have the receive 2644 * side of the ppp unit locked. 2645 */ 2646 list_for_each_entry(ch, &ppp->channels, clist) { 2647 if (seq_before(ch->lastseq, seq)) 2648 seq = ch->lastseq; 2649 } 2650 if (seq_before(ppp->minseq, seq)) 2651 ppp->minseq = seq; 2652 2653 /* Put the fragment on the reconstruction queue */ 2654 ppp_mp_insert(ppp, skb); 2655 2656 /* If the queue is getting long, don't wait any longer for packets 2657 before the start of the queue. */ 2658 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2659 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2660 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2661 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2662 } 2663 2664 /* Pull completed packets off the queue and receive them. */ 2665 while ((skb = ppp_mp_reconstruct(ppp))) { 2666 if (pskb_may_pull(skb, 2)) 2667 ppp_receive_nonmp_frame(ppp, skb); 2668 else { 2669 ++ppp->dev->stats.rx_length_errors; 2670 kfree_skb(skb); 2671 ppp_receive_error(ppp); 2672 } 2673 } 2674 2675 return; 2676 2677 err: 2678 kfree_skb(skb); 2679 ppp_receive_error(ppp); 2680 } 2681 2682 /* 2683 * Insert a fragment on the MP reconstruction queue. 2684 * The queue is ordered by increasing sequence number. 2685 */ 2686 static void 2687 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2688 { 2689 struct sk_buff *p; 2690 struct sk_buff_head *list = &ppp->mrq; 2691 u32 seq = PPP_MP_CB(skb)->sequence; 2692 2693 /* N.B. we don't need to lock the list lock because we have the 2694 ppp unit receive-side lock. */ 2695 skb_queue_walk(list, p) { 2696 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2697 break; 2698 } 2699 __skb_queue_before(list, p, skb); 2700 } 2701 2702 /* 2703 * Reconstruct a packet from the MP fragment queue. 2704 * We go through increasing sequence numbers until we find a 2705 * complete packet, or we get to the sequence number for a fragment 2706 * which hasn't arrived but might still do so. 2707 */ 2708 static struct sk_buff * 2709 ppp_mp_reconstruct(struct ppp *ppp) 2710 { 2711 u32 seq = ppp->nextseq; 2712 u32 minseq = ppp->minseq; 2713 struct sk_buff_head *list = &ppp->mrq; 2714 struct sk_buff *p, *tmp; 2715 struct sk_buff *head, *tail; 2716 struct sk_buff *skb = NULL; 2717 int lost = 0, len = 0; 2718 2719 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2720 return NULL; 2721 head = __skb_peek(list); 2722 tail = NULL; 2723 skb_queue_walk_safe(list, p, tmp) { 2724 again: 2725 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2726 /* this can't happen, anyway ignore the skb */ 2727 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2728 "seq %u < %u\n", 2729 PPP_MP_CB(p)->sequence, seq); 2730 __skb_unlink(p, list); 2731 kfree_skb(p); 2732 continue; 2733 } 2734 if (PPP_MP_CB(p)->sequence != seq) { 2735 u32 oldseq; 2736 /* Fragment `seq' is missing. If it is after 2737 minseq, it might arrive later, so stop here. */ 2738 if (seq_after(seq, minseq)) 2739 break; 2740 /* Fragment `seq' is lost, keep going. */ 2741 lost = 1; 2742 oldseq = seq; 2743 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2744 minseq + 1: PPP_MP_CB(p)->sequence; 2745 2746 if (ppp->debug & 1) 2747 netdev_printk(KERN_DEBUG, ppp->dev, 2748 "lost frag %u..%u\n", 2749 oldseq, seq-1); 2750 2751 goto again; 2752 } 2753 2754 /* 2755 * At this point we know that all the fragments from 2756 * ppp->nextseq to seq are either present or lost. 2757 * Also, there are no complete packets in the queue 2758 * that have no missing fragments and end before this 2759 * fragment. 2760 */ 2761 2762 /* B bit set indicates this fragment starts a packet */ 2763 if (PPP_MP_CB(p)->BEbits & B) { 2764 head = p; 2765 lost = 0; 2766 len = 0; 2767 } 2768 2769 len += p->len; 2770 2771 /* Got a complete packet yet? */ 2772 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2773 (PPP_MP_CB(head)->BEbits & B)) { 2774 if (len > ppp->mrru + 2) { 2775 ++ppp->dev->stats.rx_length_errors; 2776 netdev_printk(KERN_DEBUG, ppp->dev, 2777 "PPP: reconstructed packet" 2778 " is too long (%d)\n", len); 2779 } else { 2780 tail = p; 2781 break; 2782 } 2783 ppp->nextseq = seq + 1; 2784 } 2785 2786 /* 2787 * If this is the ending fragment of a packet, 2788 * and we haven't found a complete valid packet yet, 2789 * we can discard up to and including this fragment. 2790 */ 2791 if (PPP_MP_CB(p)->BEbits & E) { 2792 struct sk_buff *tmp2; 2793 2794 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2795 if (ppp->debug & 1) 2796 netdev_printk(KERN_DEBUG, ppp->dev, 2797 "discarding frag %u\n", 2798 PPP_MP_CB(p)->sequence); 2799 __skb_unlink(p, list); 2800 kfree_skb(p); 2801 } 2802 head = skb_peek(list); 2803 if (!head) 2804 break; 2805 } 2806 ++seq; 2807 } 2808 2809 /* If we have a complete packet, copy it all into one skb. */ 2810 if (tail != NULL) { 2811 /* If we have discarded any fragments, 2812 signal a receive error. */ 2813 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2814 skb_queue_walk_safe(list, p, tmp) { 2815 if (p == head) 2816 break; 2817 if (ppp->debug & 1) 2818 netdev_printk(KERN_DEBUG, ppp->dev, 2819 "discarding frag %u\n", 2820 PPP_MP_CB(p)->sequence); 2821 __skb_unlink(p, list); 2822 kfree_skb(p); 2823 } 2824 2825 if (ppp->debug & 1) 2826 netdev_printk(KERN_DEBUG, ppp->dev, 2827 " missed pkts %u..%u\n", 2828 ppp->nextseq, 2829 PPP_MP_CB(head)->sequence-1); 2830 ++ppp->dev->stats.rx_dropped; 2831 ppp_receive_error(ppp); 2832 } 2833 2834 skb = head; 2835 if (head != tail) { 2836 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2837 p = skb_queue_next(list, head); 2838 __skb_unlink(skb, list); 2839 skb_queue_walk_from_safe(list, p, tmp) { 2840 __skb_unlink(p, list); 2841 *fragpp = p; 2842 p->next = NULL; 2843 fragpp = &p->next; 2844 2845 skb->len += p->len; 2846 skb->data_len += p->len; 2847 skb->truesize += p->truesize; 2848 2849 if (p == tail) 2850 break; 2851 } 2852 } else { 2853 __skb_unlink(skb, list); 2854 } 2855 2856 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2857 } 2858 2859 return skb; 2860 } 2861 #endif /* CONFIG_PPP_MULTILINK */ 2862 2863 /* 2864 * Channel interface. 2865 */ 2866 2867 /* Create a new, unattached ppp channel. */ 2868 int ppp_register_channel(struct ppp_channel *chan) 2869 { 2870 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2871 } 2872 2873 /* Create a new, unattached ppp channel for specified net. */ 2874 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2875 { 2876 struct channel *pch; 2877 struct ppp_net *pn; 2878 2879 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2880 if (!pch) 2881 return -ENOMEM; 2882 2883 pn = ppp_pernet(net); 2884 2885 pch->ppp = NULL; 2886 pch->chan = chan; 2887 pch->chan_net = get_net(net); 2888 chan->ppp = pch; 2889 init_ppp_file(&pch->file, CHANNEL); 2890 pch->file.hdrlen = chan->hdrlen; 2891 #ifdef CONFIG_PPP_MULTILINK 2892 pch->lastseq = -1; 2893 #endif /* CONFIG_PPP_MULTILINK */ 2894 init_rwsem(&pch->chan_sem); 2895 spin_lock_init(&pch->downl); 2896 rwlock_init(&pch->upl); 2897 2898 spin_lock_bh(&pn->all_channels_lock); 2899 pch->file.index = ++pn->last_channel_index; 2900 list_add(&pch->list, &pn->new_channels); 2901 atomic_inc(&channel_count); 2902 spin_unlock_bh(&pn->all_channels_lock); 2903 2904 return 0; 2905 } 2906 2907 /* 2908 * Return the index of a channel. 2909 */ 2910 int ppp_channel_index(struct ppp_channel *chan) 2911 { 2912 struct channel *pch = chan->ppp; 2913 2914 if (pch) 2915 return pch->file.index; 2916 return -1; 2917 } 2918 2919 /* 2920 * Return the PPP unit number to which a channel is connected. 2921 */ 2922 int ppp_unit_number(struct ppp_channel *chan) 2923 { 2924 struct channel *pch = chan->ppp; 2925 int unit = -1; 2926 2927 if (pch) { 2928 read_lock_bh(&pch->upl); 2929 if (pch->ppp) 2930 unit = pch->ppp->file.index; 2931 read_unlock_bh(&pch->upl); 2932 } 2933 return unit; 2934 } 2935 2936 /* 2937 * Return the PPP device interface name of a channel. 2938 */ 2939 char *ppp_dev_name(struct ppp_channel *chan) 2940 { 2941 struct channel *pch = chan->ppp; 2942 char *name = NULL; 2943 2944 if (pch) { 2945 read_lock_bh(&pch->upl); 2946 if (pch->ppp && pch->ppp->dev) 2947 name = pch->ppp->dev->name; 2948 read_unlock_bh(&pch->upl); 2949 } 2950 return name; 2951 } 2952 2953 2954 /* 2955 * Disconnect a channel from the generic layer. 2956 * This must be called in process context. 2957 */ 2958 void 2959 ppp_unregister_channel(struct ppp_channel *chan) 2960 { 2961 struct channel *pch = chan->ppp; 2962 struct ppp_net *pn; 2963 2964 if (!pch) 2965 return; /* should never happen */ 2966 2967 chan->ppp = NULL; 2968 2969 /* 2970 * This ensures that we have returned from any calls into the 2971 * the channel's start_xmit or ioctl routine before we proceed. 2972 */ 2973 down_write(&pch->chan_sem); 2974 spin_lock_bh(&pch->downl); 2975 pch->chan = NULL; 2976 spin_unlock_bh(&pch->downl); 2977 up_write(&pch->chan_sem); 2978 ppp_disconnect_channel(pch); 2979 2980 pn = ppp_pernet(pch->chan_net); 2981 spin_lock_bh(&pn->all_channels_lock); 2982 list_del(&pch->list); 2983 spin_unlock_bh(&pn->all_channels_lock); 2984 2985 ppp_unbridge_channels(pch); 2986 2987 pch->file.dead = 1; 2988 wake_up_interruptible(&pch->file.rwait); 2989 2990 if (refcount_dec_and_test(&pch->file.refcnt)) 2991 ppp_destroy_channel(pch); 2992 } 2993 2994 /* 2995 * Callback from a channel when it can accept more to transmit. 2996 * This should be called at BH/softirq level, not interrupt level. 2997 */ 2998 void 2999 ppp_output_wakeup(struct ppp_channel *chan) 3000 { 3001 struct channel *pch = chan->ppp; 3002 3003 if (!pch) 3004 return; 3005 ppp_channel_push(pch); 3006 } 3007 3008 /* 3009 * Compression control. 3010 */ 3011 3012 /* Process the PPPIOCSCOMPRESS ioctl. */ 3013 static int 3014 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 3015 { 3016 int err = -EFAULT; 3017 struct compressor *cp, *ocomp; 3018 void *state, *ostate; 3019 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 3020 3021 if (data->length > CCP_MAX_OPTION_LENGTH) 3022 goto out; 3023 if (copy_from_user(ccp_option, data->ptr, data->length)) 3024 goto out; 3025 3026 err = -EINVAL; 3027 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 3028 goto out; 3029 3030 cp = try_then_request_module( 3031 find_compressor(ccp_option[0]), 3032 "ppp-compress-%d", ccp_option[0]); 3033 if (!cp) 3034 goto out; 3035 3036 err = -ENOBUFS; 3037 if (data->transmit) { 3038 state = cp->comp_alloc(ccp_option, data->length); 3039 if (state) { 3040 ppp_xmit_lock(ppp); 3041 ppp->xstate &= ~SC_COMP_RUN; 3042 ocomp = ppp->xcomp; 3043 ostate = ppp->xc_state; 3044 ppp->xcomp = cp; 3045 ppp->xc_state = state; 3046 ppp_xmit_unlock(ppp); 3047 if (ostate) { 3048 ocomp->comp_free(ostate); 3049 module_put(ocomp->owner); 3050 } 3051 err = 0; 3052 } else 3053 module_put(cp->owner); 3054 3055 } else { 3056 state = cp->decomp_alloc(ccp_option, data->length); 3057 if (state) { 3058 ppp_recv_lock(ppp); 3059 ppp->rstate &= ~SC_DECOMP_RUN; 3060 ocomp = ppp->rcomp; 3061 ostate = ppp->rc_state; 3062 ppp->rcomp = cp; 3063 ppp->rc_state = state; 3064 ppp_recv_unlock(ppp); 3065 if (ostate) { 3066 ocomp->decomp_free(ostate); 3067 module_put(ocomp->owner); 3068 } 3069 err = 0; 3070 } else 3071 module_put(cp->owner); 3072 } 3073 3074 out: 3075 return err; 3076 } 3077 3078 /* 3079 * Look at a CCP packet and update our state accordingly. 3080 * We assume the caller has the xmit or recv path locked. 3081 */ 3082 static void 3083 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 3084 { 3085 unsigned char *dp; 3086 int len; 3087 3088 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 3089 return; /* no header */ 3090 dp = skb->data + 2; 3091 3092 switch (CCP_CODE(dp)) { 3093 case CCP_CONFREQ: 3094 3095 /* A ConfReq starts negotiation of compression 3096 * in one direction of transmission, 3097 * and hence brings it down...but which way? 3098 * 3099 * Remember: 3100 * A ConfReq indicates what the sender would like to receive 3101 */ 3102 if(inbound) 3103 /* He is proposing what I should send */ 3104 ppp->xstate &= ~SC_COMP_RUN; 3105 else 3106 /* I am proposing to what he should send */ 3107 ppp->rstate &= ~SC_DECOMP_RUN; 3108 3109 break; 3110 3111 case CCP_TERMREQ: 3112 case CCP_TERMACK: 3113 /* 3114 * CCP is going down, both directions of transmission 3115 */ 3116 ppp->rstate &= ~SC_DECOMP_RUN; 3117 ppp->xstate &= ~SC_COMP_RUN; 3118 break; 3119 3120 case CCP_CONFACK: 3121 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 3122 break; 3123 len = CCP_LENGTH(dp); 3124 if (!pskb_may_pull(skb, len + 2)) 3125 return; /* too short */ 3126 dp += CCP_HDRLEN; 3127 len -= CCP_HDRLEN; 3128 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 3129 break; 3130 if (inbound) { 3131 /* we will start receiving compressed packets */ 3132 if (!ppp->rc_state) 3133 break; 3134 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 3135 ppp->file.index, 0, ppp->mru, ppp->debug)) { 3136 ppp->rstate |= SC_DECOMP_RUN; 3137 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 3138 } 3139 } else { 3140 /* we will soon start sending compressed packets */ 3141 if (!ppp->xc_state) 3142 break; 3143 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 3144 ppp->file.index, 0, ppp->debug)) 3145 ppp->xstate |= SC_COMP_RUN; 3146 } 3147 break; 3148 3149 case CCP_RESETACK: 3150 /* reset the [de]compressor */ 3151 if ((ppp->flags & SC_CCP_UP) == 0) 3152 break; 3153 if (inbound) { 3154 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 3155 ppp->rcomp->decomp_reset(ppp->rc_state); 3156 ppp->rstate &= ~SC_DC_ERROR; 3157 } 3158 } else { 3159 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 3160 ppp->xcomp->comp_reset(ppp->xc_state); 3161 } 3162 break; 3163 } 3164 } 3165 3166 /* Free up compression resources. */ 3167 static void 3168 ppp_ccp_closed(struct ppp *ppp) 3169 { 3170 void *xstate, *rstate; 3171 struct compressor *xcomp, *rcomp; 3172 3173 ppp_lock(ppp); 3174 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 3175 ppp->xstate = 0; 3176 xcomp = ppp->xcomp; 3177 xstate = ppp->xc_state; 3178 ppp->xc_state = NULL; 3179 ppp->rstate = 0; 3180 rcomp = ppp->rcomp; 3181 rstate = ppp->rc_state; 3182 ppp->rc_state = NULL; 3183 ppp_unlock(ppp); 3184 3185 if (xstate) { 3186 xcomp->comp_free(xstate); 3187 module_put(xcomp->owner); 3188 } 3189 if (rstate) { 3190 rcomp->decomp_free(rstate); 3191 module_put(rcomp->owner); 3192 } 3193 } 3194 3195 /* List of compressors. */ 3196 static LIST_HEAD(compressor_list); 3197 static DEFINE_SPINLOCK(compressor_list_lock); 3198 3199 struct compressor_entry { 3200 struct list_head list; 3201 struct compressor *comp; 3202 }; 3203 3204 static struct compressor_entry * 3205 find_comp_entry(int proto) 3206 { 3207 struct compressor_entry *ce; 3208 3209 list_for_each_entry(ce, &compressor_list, list) { 3210 if (ce->comp->compress_proto == proto) 3211 return ce; 3212 } 3213 return NULL; 3214 } 3215 3216 /* Register a compressor */ 3217 int 3218 ppp_register_compressor(struct compressor *cp) 3219 { 3220 struct compressor_entry *ce; 3221 int ret; 3222 spin_lock(&compressor_list_lock); 3223 ret = -EEXIST; 3224 if (find_comp_entry(cp->compress_proto)) 3225 goto out; 3226 ret = -ENOMEM; 3227 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 3228 if (!ce) 3229 goto out; 3230 ret = 0; 3231 ce->comp = cp; 3232 list_add(&ce->list, &compressor_list); 3233 out: 3234 spin_unlock(&compressor_list_lock); 3235 return ret; 3236 } 3237 3238 /* Unregister a compressor */ 3239 void 3240 ppp_unregister_compressor(struct compressor *cp) 3241 { 3242 struct compressor_entry *ce; 3243 3244 spin_lock(&compressor_list_lock); 3245 ce = find_comp_entry(cp->compress_proto); 3246 if (ce && ce->comp == cp) { 3247 list_del(&ce->list); 3248 kfree(ce); 3249 } 3250 spin_unlock(&compressor_list_lock); 3251 } 3252 3253 /* Find a compressor. */ 3254 static struct compressor * 3255 find_compressor(int type) 3256 { 3257 struct compressor_entry *ce; 3258 struct compressor *cp = NULL; 3259 3260 spin_lock(&compressor_list_lock); 3261 ce = find_comp_entry(type); 3262 if (ce) { 3263 cp = ce->comp; 3264 if (!try_module_get(cp->owner)) 3265 cp = NULL; 3266 } 3267 spin_unlock(&compressor_list_lock); 3268 return cp; 3269 } 3270 3271 /* 3272 * Miscelleneous stuff. 3273 */ 3274 3275 static void 3276 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3277 { 3278 struct slcompress *vj = ppp->vj; 3279 3280 memset(st, 0, sizeof(*st)); 3281 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3282 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3283 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3284 st->p.ppp_opackets = ppp->stats64.tx_packets; 3285 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3286 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3287 if (!vj) 3288 return; 3289 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3290 st->vj.vjs_compressed = vj->sls_o_compressed; 3291 st->vj.vjs_searches = vj->sls_o_searches; 3292 st->vj.vjs_misses = vj->sls_o_misses; 3293 st->vj.vjs_errorin = vj->sls_i_error; 3294 st->vj.vjs_tossed = vj->sls_i_tossed; 3295 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3296 st->vj.vjs_compressedin = vj->sls_i_compressed; 3297 } 3298 3299 /* 3300 * Stuff for handling the lists of ppp units and channels 3301 * and for initialization. 3302 */ 3303 3304 /* 3305 * Create a new ppp interface unit. Fails if it can't allocate memory 3306 * or if there is already a unit with the requested number. 3307 * unit == -1 means allocate a new number. 3308 */ 3309 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3310 { 3311 struct ppp_config conf = { 3312 .file = file, 3313 .unit = *unit, 3314 .ifname_is_set = false, 3315 }; 3316 struct net_device *dev; 3317 struct ppp *ppp; 3318 int err; 3319 3320 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3321 if (!dev) { 3322 err = -ENOMEM; 3323 goto err; 3324 } 3325 dev_net_set(dev, net); 3326 dev->rtnl_link_ops = &ppp_link_ops; 3327 3328 rtnl_lock(); 3329 3330 err = ppp_dev_configure(net, dev, &conf); 3331 if (err < 0) 3332 goto err_dev; 3333 ppp = netdev_priv(dev); 3334 *unit = ppp->file.index; 3335 3336 rtnl_unlock(); 3337 3338 return 0; 3339 3340 err_dev: 3341 rtnl_unlock(); 3342 free_netdev(dev); 3343 err: 3344 return err; 3345 } 3346 3347 /* 3348 * Initialize a ppp_file structure. 3349 */ 3350 static void 3351 init_ppp_file(struct ppp_file *pf, int kind) 3352 { 3353 pf->kind = kind; 3354 skb_queue_head_init(&pf->xq); 3355 skb_queue_head_init(&pf->rq); 3356 refcount_set(&pf->refcnt, 1); 3357 init_waitqueue_head(&pf->rwait); 3358 } 3359 3360 /* 3361 * Free the memory used by a ppp unit. This is only called once 3362 * there are no channels connected to the unit and no file structs 3363 * that reference the unit. 3364 */ 3365 static void ppp_destroy_interface(struct ppp *ppp) 3366 { 3367 atomic_dec(&ppp_unit_count); 3368 3369 if (!ppp->file.dead || ppp->n_channels) { 3370 /* "can't happen" */ 3371 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3372 "but dead=%d n_channels=%d !\n", 3373 ppp, ppp->file.dead, ppp->n_channels); 3374 return; 3375 } 3376 3377 ppp_ccp_closed(ppp); 3378 if (ppp->vj) { 3379 slhc_free(ppp->vj); 3380 ppp->vj = NULL; 3381 } 3382 skb_queue_purge(&ppp->file.xq); 3383 skb_queue_purge(&ppp->file.rq); 3384 #ifdef CONFIG_PPP_MULTILINK 3385 skb_queue_purge(&ppp->mrq); 3386 #endif /* CONFIG_PPP_MULTILINK */ 3387 #ifdef CONFIG_PPP_FILTER 3388 if (ppp->pass_filter) { 3389 bpf_prog_destroy(ppp->pass_filter); 3390 ppp->pass_filter = NULL; 3391 } 3392 3393 if (ppp->active_filter) { 3394 bpf_prog_destroy(ppp->active_filter); 3395 ppp->active_filter = NULL; 3396 } 3397 #endif /* CONFIG_PPP_FILTER */ 3398 3399 kfree_skb(ppp->xmit_pending); 3400 free_percpu(ppp->xmit_recursion); 3401 3402 free_netdev(ppp->dev); 3403 } 3404 3405 /* 3406 * Locate an existing ppp unit. 3407 * The caller should have locked the all_ppp_mutex. 3408 */ 3409 static struct ppp * 3410 ppp_find_unit(struct ppp_net *pn, int unit) 3411 { 3412 return unit_find(&pn->units_idr, unit); 3413 } 3414 3415 /* 3416 * Locate an existing ppp channel. 3417 * The caller should have locked the all_channels_lock. 3418 * First we look in the new_channels list, then in the 3419 * all_channels list. If found in the new_channels list, 3420 * we move it to the all_channels list. This is for speed 3421 * when we have a lot of channels in use. 3422 */ 3423 static struct channel * 3424 ppp_find_channel(struct ppp_net *pn, int unit) 3425 { 3426 struct channel *pch; 3427 3428 list_for_each_entry(pch, &pn->new_channels, list) { 3429 if (pch->file.index == unit) { 3430 list_move(&pch->list, &pn->all_channels); 3431 return pch; 3432 } 3433 } 3434 3435 list_for_each_entry(pch, &pn->all_channels, list) { 3436 if (pch->file.index == unit) 3437 return pch; 3438 } 3439 3440 return NULL; 3441 } 3442 3443 /* 3444 * Connect a PPP channel to a PPP interface unit. 3445 */ 3446 static int 3447 ppp_connect_channel(struct channel *pch, int unit) 3448 { 3449 struct ppp *ppp; 3450 struct ppp_net *pn; 3451 int ret = -ENXIO; 3452 int hdrlen; 3453 3454 pn = ppp_pernet(pch->chan_net); 3455 3456 mutex_lock(&pn->all_ppp_mutex); 3457 ppp = ppp_find_unit(pn, unit); 3458 if (!ppp) 3459 goto out; 3460 write_lock_bh(&pch->upl); 3461 ret = -EINVAL; 3462 if (pch->ppp || 3463 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) 3464 goto outl; 3465 3466 ppp_lock(ppp); 3467 spin_lock_bh(&pch->downl); 3468 if (!pch->chan) { 3469 /* Don't connect unregistered channels */ 3470 spin_unlock_bh(&pch->downl); 3471 ppp_unlock(ppp); 3472 ret = -ENOTCONN; 3473 goto outl; 3474 } 3475 spin_unlock_bh(&pch->downl); 3476 if (pch->file.hdrlen > ppp->file.hdrlen) 3477 ppp->file.hdrlen = pch->file.hdrlen; 3478 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3479 if (hdrlen > ppp->dev->hard_header_len) 3480 ppp->dev->hard_header_len = hdrlen; 3481 list_add_tail(&pch->clist, &ppp->channels); 3482 ++ppp->n_channels; 3483 pch->ppp = ppp; 3484 refcount_inc(&ppp->file.refcnt); 3485 ppp_unlock(ppp); 3486 ret = 0; 3487 3488 outl: 3489 write_unlock_bh(&pch->upl); 3490 out: 3491 mutex_unlock(&pn->all_ppp_mutex); 3492 return ret; 3493 } 3494 3495 /* 3496 * Disconnect a channel from its ppp unit. 3497 */ 3498 static int 3499 ppp_disconnect_channel(struct channel *pch) 3500 { 3501 struct ppp *ppp; 3502 int err = -EINVAL; 3503 3504 write_lock_bh(&pch->upl); 3505 ppp = pch->ppp; 3506 pch->ppp = NULL; 3507 write_unlock_bh(&pch->upl); 3508 if (ppp) { 3509 /* remove it from the ppp unit's list */ 3510 ppp_lock(ppp); 3511 list_del(&pch->clist); 3512 if (--ppp->n_channels == 0) 3513 wake_up_interruptible(&ppp->file.rwait); 3514 ppp_unlock(ppp); 3515 if (refcount_dec_and_test(&ppp->file.refcnt)) 3516 ppp_destroy_interface(ppp); 3517 err = 0; 3518 } 3519 return err; 3520 } 3521 3522 /* 3523 * Free up the resources used by a ppp channel. 3524 */ 3525 static void ppp_destroy_channel(struct channel *pch) 3526 { 3527 put_net(pch->chan_net); 3528 pch->chan_net = NULL; 3529 3530 atomic_dec(&channel_count); 3531 3532 if (!pch->file.dead) { 3533 /* "can't happen" */ 3534 pr_err("ppp: destroying undead channel %p !\n", pch); 3535 return; 3536 } 3537 skb_queue_purge(&pch->file.xq); 3538 skb_queue_purge(&pch->file.rq); 3539 kfree(pch); 3540 } 3541 3542 static void __exit ppp_cleanup(void) 3543 { 3544 /* should never happen */ 3545 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3546 pr_err("PPP: removing module but units remain!\n"); 3547 rtnl_link_unregister(&ppp_link_ops); 3548 unregister_chrdev(PPP_MAJOR, "ppp"); 3549 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3550 class_destroy(ppp_class); 3551 unregister_pernet_device(&ppp_net_ops); 3552 } 3553 3554 /* 3555 * Units handling. Caller must protect concurrent access 3556 * by holding all_ppp_mutex 3557 */ 3558 3559 /* associate pointer with specified number */ 3560 static int unit_set(struct idr *p, void *ptr, int n) 3561 { 3562 int unit; 3563 3564 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3565 if (unit == -ENOSPC) 3566 unit = -EINVAL; 3567 return unit; 3568 } 3569 3570 /* get new free unit number and associate pointer with it */ 3571 static int unit_get(struct idr *p, void *ptr, int min) 3572 { 3573 return idr_alloc(p, ptr, min, 0, GFP_KERNEL); 3574 } 3575 3576 /* put unit number back to a pool */ 3577 static void unit_put(struct idr *p, int n) 3578 { 3579 idr_remove(p, n); 3580 } 3581 3582 /* get pointer associated with the number */ 3583 static void *unit_find(struct idr *p, int n) 3584 { 3585 return idr_find(p, n); 3586 } 3587 3588 /* Module/initialization stuff */ 3589 3590 module_init(ppp_init); 3591 module_exit(ppp_cleanup); 3592 3593 EXPORT_SYMBOL(ppp_register_net_channel); 3594 EXPORT_SYMBOL(ppp_register_channel); 3595 EXPORT_SYMBOL(ppp_unregister_channel); 3596 EXPORT_SYMBOL(ppp_channel_index); 3597 EXPORT_SYMBOL(ppp_unit_number); 3598 EXPORT_SYMBOL(ppp_dev_name); 3599 EXPORT_SYMBOL(ppp_input); 3600 EXPORT_SYMBOL(ppp_input_error); 3601 EXPORT_SYMBOL(ppp_output_wakeup); 3602 EXPORT_SYMBOL(ppp_register_compressor); 3603 EXPORT_SYMBOL(ppp_unregister_compressor); 3604 MODULE_LICENSE("GPL"); 3605 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3606 MODULE_ALIAS_RTNL_LINK("ppp"); 3607 MODULE_ALIAS("devname:ppp"); 3608