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/rculist.h> 37 #include <linux/rtnetlink.h> 38 #include <linux/if_arp.h> 39 #include <linux/ip.h> 40 #include <linux/tcp.h> 41 #include <linux/spinlock.h> 42 #include <linux/rwsem.h> 43 #include <linux/stddef.h> 44 #include <linux/device.h> 45 #include <linux/mutex.h> 46 #include <linux/slab.h> 47 #include <linux/file.h> 48 #include <linux/unaligned.h> 49 #include <net/netdev_lock.h> 50 #include <net/slhc_vj.h> 51 #include <linux/atomic.h> 52 #include <linux/refcount.h> 53 54 #include <linux/nsproxy.h> 55 #include <net/net_namespace.h> 56 #include <net/netns/generic.h> 57 58 #define PPP_VERSION "2.4.2" 59 60 /* 61 * Network protocols we support. 62 */ 63 #define NP_IP 0 /* Internet Protocol V4 */ 64 #define NP_IPV6 1 /* Internet Protocol V6 */ 65 #define NP_IPX 2 /* IPX protocol */ 66 #define NP_AT 3 /* Appletalk protocol */ 67 #define NP_MPLS_UC 4 /* MPLS unicast */ 68 #define NP_MPLS_MC 5 /* MPLS multicast */ 69 #define NUM_NP 6 /* Number of NPs. */ 70 71 #define MPHDRLEN 6 /* multilink protocol header length */ 72 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 73 74 #define PPP_PROTO_LEN 2 75 #define PPP_LCP_HDRLEN 4 76 77 /* The filter instructions generated by libpcap are constructed 78 * assuming a four-byte PPP header on each packet, where the last 79 * 2 bytes are the protocol field defined in the RFC and the first 80 * byte of the first 2 bytes indicates the direction. 81 * The second byte is currently unused, but we still need to initialize 82 * it to prevent crafted BPF programs from reading them which would 83 * cause reading of uninitialized data. 84 */ 85 #define PPP_FILTER_OUTBOUND_TAG 0x0100 86 #define PPP_FILTER_INBOUND_TAG 0x0000 87 88 /* 89 * An instance of /dev/ppp can be associated with either a ppp 90 * interface unit or a ppp channel. In both cases, file->private_data 91 * points to one of these. 92 */ 93 struct ppp_file { 94 enum { 95 INTERFACE=1, CHANNEL 96 } kind; 97 struct sk_buff_head xq; /* pppd transmit queue */ 98 struct sk_buff_head rq; /* receive queue for pppd */ 99 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 100 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 101 int hdrlen; /* space to leave for headers */ 102 int index; /* interface unit / channel number */ 103 int dead; /* unit/channel has been shut down */ 104 }; 105 106 #define PF_TO_X(pf, X) container_of(pf, X, file) 107 108 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 109 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 110 111 struct ppp_xmit_recursion { 112 struct task_struct *owner; 113 local_lock_t bh_lock; 114 }; 115 116 /* 117 * Data structure describing one ppp unit. 118 * A ppp unit corresponds to a ppp network interface device 119 * and represents a multilink bundle. 120 * It can have 0 or more ppp channels connected to it. 121 */ 122 struct ppp { 123 struct ppp_file file; /* stuff for read/write/poll 0 */ 124 struct file *owner; /* file that owns this unit 48 */ 125 struct list_head channels; /* list of attached channels 4c */ 126 int n_channels; /* how many channels are attached 54 */ 127 spinlock_t rlock; /* lock for receive side 58 */ 128 spinlock_t wlock; /* lock for transmit side 5c */ 129 struct ppp_xmit_recursion __percpu *xmit_recursion; /* xmit recursion detect */ 130 int mru; /* max receive unit 60 */ 131 unsigned int flags; /* control bits 64 */ 132 unsigned int xstate; /* transmit state bits 68 */ 133 unsigned int rstate; /* receive state bits 6c */ 134 int debug; /* debug flags 70 */ 135 struct slcompress *vj; /* state for VJ header compression */ 136 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 137 struct compressor *xcomp; /* transmit packet compressor 8c */ 138 void *xc_state; /* its internal state 90 */ 139 struct compressor *rcomp; /* receive decompressor 94 */ 140 void *rc_state; /* its internal state 98 */ 141 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 142 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 143 struct net_device *dev; /* network interface device a4 */ 144 int closing; /* is device closing down? a8 */ 145 #ifdef CONFIG_PPP_MULTILINK 146 int nxchan; /* next channel to send something on */ 147 u32 nxseq; /* next sequence number to send */ 148 int mrru; /* MP: max reconst. receive unit */ 149 u32 nextseq; /* MP: seq no of next packet */ 150 u32 minseq; /* MP: min of most recent seqnos */ 151 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 152 #endif /* CONFIG_PPP_MULTILINK */ 153 #ifdef CONFIG_PPP_FILTER 154 struct bpf_prog *pass_filter; /* filter for packets to pass */ 155 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 156 #endif /* CONFIG_PPP_FILTER */ 157 struct net *ppp_net; /* the net we belong to */ 158 }; 159 160 /* 161 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 162 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 163 * SC_MUST_COMP 164 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 165 * Bits in xstate: SC_COMP_RUN 166 */ 167 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 168 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 169 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 170 171 /* 172 * Private data structure for each channel. 173 * This includes the data structure used for multilink. 174 */ 175 struct channel { 176 struct ppp_file file; /* stuff for read/write/poll */ 177 struct list_head list; /* link in all/new_channels list */ 178 struct ppp_channel *chan; /* public channel data structure */ 179 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 180 spinlock_t downl; /* protects `chan', file.xq dequeue */ 181 struct ppp __rcu *ppp; /* ppp unit we're connected to */ 182 struct net *chan_net; /* the net channel belongs to */ 183 netns_tracker ns_tracker; 184 struct list_head clist; /* link in list of channels per unit */ 185 spinlock_t upl; /* protects `ppp' and 'bridge' */ 186 struct channel __rcu *bridge; /* "bridged" ppp channel */ 187 #ifdef CONFIG_PPP_MULTILINK 188 u8 avail; /* flag used in multilink stuff */ 189 u8 had_frag; /* >= 1 fragments have been sent */ 190 u32 lastseq; /* MP: last sequence # received */ 191 int speed; /* speed of the corresponding ppp channel*/ 192 #endif /* CONFIG_PPP_MULTILINK */ 193 }; 194 195 struct ppp_config { 196 struct file *file; 197 s32 unit; 198 bool ifname_is_set; 199 }; 200 201 /* 202 * SMP locking issues: 203 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 204 * list and the ppp.n_channels field, you need to take both locks 205 * before you modify them. 206 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 207 * channel.downl. 208 */ 209 210 static DEFINE_MUTEX(ppp_mutex); 211 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 212 static atomic_t channel_count = ATOMIC_INIT(0); 213 214 /* per-net private data for this module */ 215 static unsigned int ppp_net_id __read_mostly; 216 struct ppp_net { 217 /* units to ppp mapping */ 218 struct idr units_idr; 219 220 /* 221 * all_ppp_mutex protects the units_idr mapping. 222 * It also ensures that finding a ppp unit in the units_idr 223 * map and updating its file.refcnt field is atomic. 224 */ 225 struct mutex all_ppp_mutex; 226 227 /* channels */ 228 struct list_head all_channels; 229 struct list_head new_channels; 230 int last_channel_index; 231 232 /* 233 * all_channels_lock protects all_channels and 234 * last_channel_index, and the atomicity of find 235 * a channel and updating its file.refcnt field. 236 */ 237 spinlock_t all_channels_lock; 238 }; 239 240 /* Get the PPP protocol number from a skb */ 241 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 242 243 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 244 #define PPP_MAX_RQLEN 32 245 246 /* 247 * Maximum number of multilink fragments queued up. 248 * This has to be large enough to cope with the maximum latency of 249 * the slowest channel relative to the others. Strictly it should 250 * depend on the number of channels and their characteristics. 251 */ 252 #define PPP_MP_MAX_QLEN 128 253 254 /* Multilink header bits. */ 255 #define B 0x80 /* this fragment begins a packet */ 256 #define E 0x40 /* this fragment ends a packet */ 257 258 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 259 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 260 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 261 262 /* Prototypes. */ 263 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 264 struct file *file, unsigned int cmd, unsigned long arg); 265 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 266 static int ppp_prepare_tx_skb(struct ppp *ppp, struct sk_buff **pskb); 267 static int ppp_push(struct ppp *ppp, struct sk_buff *skb); 268 static void ppp_channel_push(struct channel *pch); 269 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 270 struct channel *pch); 271 static void ppp_receive_error(struct ppp *ppp); 272 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 273 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 274 struct sk_buff *skb); 275 #ifdef CONFIG_PPP_MULTILINK 276 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 277 struct channel *pch); 278 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 279 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 280 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 281 #endif /* CONFIG_PPP_MULTILINK */ 282 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data); 283 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 284 static void ppp_ccp_closed(struct ppp *ppp); 285 static struct compressor *find_compressor(int type); 286 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 287 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 288 static void init_ppp_file(struct ppp_file *pf, int kind); 289 static void ppp_release_interface(struct ppp *ppp); 290 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 291 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 292 static int ppp_connect_channel(struct channel *pch, int unit); 293 static int ppp_disconnect_channel(struct channel *pch); 294 static void ppp_release_channel(struct channel *pch); 295 static int unit_get(struct idr *p, void *ptr, int min); 296 static int unit_set(struct idr *p, void *ptr, int n); 297 static void unit_put(struct idr *p, int n); 298 static void *unit_find(struct idr *p, int n); 299 static void ppp_setup(struct net_device *dev); 300 301 static const struct net_device_ops ppp_netdev_ops; 302 303 static const struct class ppp_class = { 304 .name = "ppp", 305 }; 306 307 /* per net-namespace data */ 308 static inline struct ppp_net *ppp_pernet(struct net *net) 309 { 310 return net_generic(net, ppp_net_id); 311 } 312 313 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 314 static inline int proto_to_npindex(int proto) 315 { 316 switch (proto) { 317 case PPP_IP: 318 return NP_IP; 319 case PPP_IPV6: 320 return NP_IPV6; 321 case PPP_IPX: 322 return NP_IPX; 323 case PPP_AT: 324 return NP_AT; 325 case PPP_MPLS_UC: 326 return NP_MPLS_UC; 327 case PPP_MPLS_MC: 328 return NP_MPLS_MC; 329 } 330 return -EINVAL; 331 } 332 333 /* Translates an NP index into a PPP protocol number */ 334 static const int npindex_to_proto[NUM_NP] = { 335 PPP_IP, 336 PPP_IPV6, 337 PPP_IPX, 338 PPP_AT, 339 PPP_MPLS_UC, 340 PPP_MPLS_MC, 341 }; 342 343 /* Translates an ethertype into an NP index */ 344 static inline int ethertype_to_npindex(int ethertype) 345 { 346 switch (ethertype) { 347 case ETH_P_IP: 348 return NP_IP; 349 case ETH_P_IPV6: 350 return NP_IPV6; 351 case ETH_P_IPX: 352 return NP_IPX; 353 case ETH_P_PPPTALK: 354 case ETH_P_ATALK: 355 return NP_AT; 356 case ETH_P_MPLS_UC: 357 return NP_MPLS_UC; 358 case ETH_P_MPLS_MC: 359 return NP_MPLS_MC; 360 } 361 return -1; 362 } 363 364 /* Translates an NP index into an ethertype */ 365 static const int npindex_to_ethertype[NUM_NP] = { 366 ETH_P_IP, 367 ETH_P_IPV6, 368 ETH_P_IPX, 369 ETH_P_PPPTALK, 370 ETH_P_MPLS_UC, 371 ETH_P_MPLS_MC, 372 }; 373 374 /* 375 * Locking shorthand. 376 */ 377 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 378 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 379 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 380 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 381 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 382 ppp_recv_lock(ppp); } while (0) 383 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 384 ppp_xmit_unlock(ppp); } while (0) 385 386 /* 387 * /dev/ppp device routines. 388 * The /dev/ppp device is used by pppd to control the ppp unit. 389 * It supports the read, write, ioctl and poll functions. 390 * Open instances of /dev/ppp can be in one of three states: 391 * unattached, attached to a ppp unit, or attached to a ppp channel. 392 */ 393 static int ppp_open(struct inode *inode, struct file *file) 394 { 395 /* 396 * This could (should?) be enforced by the permissions on /dev/ppp. 397 */ 398 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 399 return -EPERM; 400 return 0; 401 } 402 403 static int ppp_release(struct inode *unused, struct file *file) 404 { 405 struct ppp_file *pf = file->private_data; 406 struct ppp *ppp; 407 408 if (pf) { 409 file->private_data = NULL; 410 switch (pf->kind) { 411 case INTERFACE: 412 ppp = PF_TO_PPP(pf); 413 rtnl_lock(); 414 if (file == ppp->owner) 415 unregister_netdevice(ppp->dev); 416 rtnl_unlock(); 417 ppp_release_interface(ppp); 418 break; 419 case CHANNEL: 420 ppp_release_channel(PF_TO_CHANNEL(pf)); 421 break; 422 } 423 } 424 return 0; 425 } 426 427 static ssize_t ppp_read(struct file *file, char __user *buf, 428 size_t count, loff_t *ppos) 429 { 430 struct ppp_file *pf = file->private_data; 431 DECLARE_WAITQUEUE(wait, current); 432 ssize_t ret; 433 struct sk_buff *skb = NULL; 434 struct iovec iov; 435 struct iov_iter to; 436 437 ret = count; 438 439 if (!pf) 440 return -ENXIO; 441 add_wait_queue(&pf->rwait, &wait); 442 for (;;) { 443 set_current_state(TASK_INTERRUPTIBLE); 444 skb = skb_dequeue(&pf->rq); 445 if (skb) 446 break; 447 ret = 0; 448 if (pf->dead) 449 break; 450 if (pf->kind == INTERFACE) { 451 /* 452 * Return 0 (EOF) on an interface that has no 453 * channels connected, unless it is looping 454 * network traffic (demand mode). 455 */ 456 struct ppp *ppp = PF_TO_PPP(pf); 457 458 ppp_recv_lock(ppp); 459 if (ppp->n_channels == 0 && 460 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 461 ppp_recv_unlock(ppp); 462 break; 463 } 464 ppp_recv_unlock(ppp); 465 } 466 ret = -EAGAIN; 467 if (file->f_flags & O_NONBLOCK) 468 break; 469 ret = -ERESTARTSYS; 470 if (signal_pending(current)) 471 break; 472 schedule(); 473 } 474 set_current_state(TASK_RUNNING); 475 remove_wait_queue(&pf->rwait, &wait); 476 477 if (!skb) 478 goto out; 479 480 ret = -EOVERFLOW; 481 if (skb->len > count) 482 goto outf; 483 ret = -EFAULT; 484 iov.iov_base = buf; 485 iov.iov_len = count; 486 iov_iter_init(&to, ITER_DEST, &iov, 1, count); 487 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 488 goto outf; 489 ret = skb->len; 490 491 outf: 492 kfree_skb(skb); 493 out: 494 return ret; 495 } 496 497 static bool ppp_check_packet(struct sk_buff *skb, size_t count) 498 { 499 /* LCP packets must include LCP header which 4 bytes long: 500 * 1-byte code, 1-byte identifier, and 2-byte length. 501 */ 502 return get_unaligned_be16(skb->data) != PPP_LCP || 503 count >= PPP_PROTO_LEN + PPP_LCP_HDRLEN; 504 } 505 506 static ssize_t ppp_write(struct file *file, const char __user *buf, 507 size_t count, loff_t *ppos) 508 { 509 struct ppp_file *pf = file->private_data; 510 struct sk_buff *skb; 511 ssize_t ret; 512 513 if (!pf) 514 return -ENXIO; 515 /* All PPP packets should start with the 2-byte protocol */ 516 if (count < PPP_PROTO_LEN) 517 return -EINVAL; 518 ret = -ENOMEM; 519 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 520 if (!skb) 521 goto out; 522 skb_reserve(skb, pf->hdrlen); 523 ret = -EFAULT; 524 if (copy_from_user(skb_put(skb, count), buf, count)) { 525 kfree_skb(skb); 526 goto out; 527 } 528 ret = -EINVAL; 529 if (unlikely(!ppp_check_packet(skb, count))) { 530 kfree_skb(skb); 531 goto out; 532 } 533 534 switch (pf->kind) { 535 case INTERFACE: 536 ppp_xmit_process(PF_TO_PPP(pf), skb); 537 break; 538 case CHANNEL: 539 skb_queue_tail(&pf->xq, skb); 540 ppp_channel_push(PF_TO_CHANNEL(pf)); 541 break; 542 } 543 544 ret = count; 545 546 out: 547 return ret; 548 } 549 550 /* No kernel lock - fine */ 551 static __poll_t ppp_poll(struct file *file, poll_table *wait) 552 { 553 struct ppp_file *pf = file->private_data; 554 __poll_t mask; 555 556 if (!pf) 557 return 0; 558 poll_wait(file, &pf->rwait, wait); 559 mask = EPOLLOUT | EPOLLWRNORM; 560 if (skb_peek(&pf->rq)) 561 mask |= EPOLLIN | EPOLLRDNORM; 562 if (pf->dead) 563 mask |= EPOLLHUP; 564 else if (pf->kind == INTERFACE) { 565 /* see comment in ppp_read */ 566 struct ppp *ppp = PF_TO_PPP(pf); 567 568 ppp_recv_lock(ppp); 569 if (ppp->n_channels == 0 && 570 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 571 mask |= EPOLLIN | EPOLLRDNORM; 572 ppp_recv_unlock(ppp); 573 } 574 575 return mask; 576 } 577 578 #ifdef CONFIG_PPP_FILTER 579 static struct bpf_prog *get_filter(struct sock_fprog *uprog) 580 { 581 struct sock_fprog_kern fprog; 582 struct bpf_prog *res = NULL; 583 int err; 584 585 if (!uprog->len) 586 return NULL; 587 588 /* uprog->len is unsigned short, so no overflow here */ 589 fprog.len = uprog->len; 590 fprog.filter = memdup_array_user(uprog->filter, 591 uprog->len, sizeof(struct sock_filter)); 592 if (IS_ERR(fprog.filter)) 593 return ERR_CAST(fprog.filter); 594 595 err = bpf_prog_create(&res, &fprog); 596 kfree(fprog.filter); 597 598 return err ? ERR_PTR(err) : res; 599 } 600 601 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p) 602 { 603 struct sock_fprog uprog; 604 605 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog))) 606 return ERR_PTR(-EFAULT); 607 return get_filter(&uprog); 608 } 609 610 #ifdef CONFIG_COMPAT 611 struct sock_fprog32 { 612 unsigned short len; 613 compat_caddr_t filter; 614 }; 615 616 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32) 617 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32) 618 619 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) 620 { 621 struct sock_fprog32 uprog32; 622 struct sock_fprog uprog; 623 624 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32))) 625 return ERR_PTR(-EFAULT); 626 uprog.len = uprog32.len; 627 uprog.filter = compat_ptr(uprog32.filter); 628 return get_filter(&uprog); 629 } 630 #endif 631 #endif 632 633 /* Bridge one PPP channel to another. 634 * When two channels are bridged, ppp_input on one channel is redirected to 635 * the other's ops->start_xmit handler. 636 * In order to safely bridge channels we must reject channels which are already 637 * part of a bridge instance, or which form part of an existing unit. 638 * Once successfully bridged, each channel holds a reference on the other 639 * to prevent it being freed while the bridge is extant. 640 */ 641 static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) 642 { 643 spin_lock(&pch->upl); 644 if (rcu_dereference_protected(pch->ppp, lockdep_is_held(&pch->upl)) || 645 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) { 646 spin_unlock(&pch->upl); 647 return -EALREADY; 648 } 649 refcount_inc(&pchb->file.refcnt); 650 rcu_assign_pointer(pch->bridge, pchb); 651 spin_unlock(&pch->upl); 652 653 spin_lock(&pchb->upl); 654 if (rcu_dereference_protected(pchb->ppp, lockdep_is_held(&pchb->upl)) || 655 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) { 656 spin_unlock(&pchb->upl); 657 goto err_unset; 658 } 659 refcount_inc(&pch->file.refcnt); 660 rcu_assign_pointer(pchb->bridge, pch); 661 spin_unlock(&pchb->upl); 662 663 return 0; 664 665 err_unset: 666 spin_lock(&pch->upl); 667 /* Re-read pch->bridge with upl held in case it was modified concurrently */ 668 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 669 RCU_INIT_POINTER(pch->bridge, NULL); 670 spin_unlock(&pch->upl); 671 synchronize_rcu(); 672 673 if (pchb) 674 ppp_release_channel(pchb); 675 676 return -EALREADY; 677 } 678 679 static int ppp_unbridge_channels(struct channel *pch) 680 { 681 struct channel *pchb, *pchbb; 682 683 spin_lock(&pch->upl); 684 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 685 if (!pchb) { 686 spin_unlock(&pch->upl); 687 return -EINVAL; 688 } 689 RCU_INIT_POINTER(pch->bridge, NULL); 690 spin_unlock(&pch->upl); 691 692 /* Only modify pchb if phcb->bridge points back to pch. 693 * If not, it implies that there has been a race unbridging (and possibly 694 * even rebridging) pchb. We should leave pchb alone to avoid either a 695 * refcount underflow, or breaking another established bridge instance. 696 */ 697 spin_lock(&pchb->upl); 698 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl)); 699 if (pchbb == pch) 700 RCU_INIT_POINTER(pchb->bridge, NULL); 701 spin_unlock(&pchb->upl); 702 703 synchronize_rcu(); 704 705 if (pchbb == pch) 706 ppp_release_channel(pch); 707 708 ppp_release_channel(pchb); 709 710 return 0; 711 } 712 713 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 714 { 715 struct ppp_file *pf; 716 struct ppp *ppp; 717 int err = -EFAULT, val, val2, i; 718 struct ppp_idle32 idle32; 719 struct ppp_idle64 idle64; 720 struct npioctl npi; 721 int unit, cflags; 722 struct slcompress *vj; 723 void __user *argp = (void __user *)arg; 724 int __user *p = argp; 725 726 mutex_lock(&ppp_mutex); 727 728 pf = file->private_data; 729 if (!pf) { 730 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 731 pf, file, cmd, arg); 732 goto out; 733 } 734 735 if (cmd == PPPIOCDETACH) { 736 /* 737 * PPPIOCDETACH is no longer supported as it was heavily broken, 738 * and is only known to have been used by pppd older than 739 * ppp-2.4.2 (released November 2003). 740 */ 741 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 742 current->comm, current->pid); 743 err = -EINVAL; 744 goto out; 745 } 746 747 if (pf->kind == CHANNEL) { 748 struct channel *pch, *pchb; 749 struct ppp_channel *chan; 750 struct ppp_net *pn; 751 752 pch = PF_TO_CHANNEL(pf); 753 754 switch (cmd) { 755 case PPPIOCCONNECT: 756 if (get_user(unit, p)) 757 break; 758 err = ppp_connect_channel(pch, unit); 759 break; 760 761 case PPPIOCDISCONN: 762 err = ppp_disconnect_channel(pch); 763 break; 764 765 case PPPIOCBRIDGECHAN: 766 if (get_user(unit, p)) 767 break; 768 err = -ENXIO; 769 pn = ppp_pernet(current->nsproxy->net_ns); 770 spin_lock_bh(&pn->all_channels_lock); 771 pchb = ppp_find_channel(pn, unit); 772 /* Hold a reference to prevent pchb being freed while 773 * we establish the bridge. 774 */ 775 if (pchb) 776 refcount_inc(&pchb->file.refcnt); 777 spin_unlock_bh(&pn->all_channels_lock); 778 if (!pchb) 779 break; 780 err = ppp_bridge_channels(pch, pchb); 781 /* Drop earlier refcount now bridge establishment is complete */ 782 ppp_release_channel(pchb); 783 break; 784 785 case PPPIOCUNBRIDGECHAN: 786 err = ppp_unbridge_channels(pch); 787 break; 788 789 default: 790 down_read(&pch->chan_sem); 791 chan = pch->chan; 792 err = -ENOTTY; 793 if (chan && chan->ops->ioctl) 794 err = chan->ops->ioctl(chan, cmd, arg); 795 up_read(&pch->chan_sem); 796 } 797 goto out; 798 } 799 800 if (pf->kind != INTERFACE) { 801 /* can't happen */ 802 pr_err("PPP: not interface or channel??\n"); 803 err = -EINVAL; 804 goto out; 805 } 806 807 ppp = PF_TO_PPP(pf); 808 switch (cmd) { 809 case PPPIOCSMRU: 810 if (get_user(val, p)) 811 break; 812 ppp->mru = val; 813 err = 0; 814 break; 815 816 case PPPIOCSFLAGS: 817 if (get_user(val, p)) 818 break; 819 ppp_lock(ppp); 820 cflags = ppp->flags & ~val; 821 #ifdef CONFIG_PPP_MULTILINK 822 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 823 ppp->nextseq = 0; 824 #endif 825 ppp->flags = val & SC_FLAG_BITS; 826 ppp_unlock(ppp); 827 if (cflags & SC_CCP_OPEN) 828 ppp_ccp_closed(ppp); 829 err = 0; 830 break; 831 832 case PPPIOCGFLAGS: 833 val = ppp->flags | ppp->xstate | ppp->rstate; 834 if (put_user(val, p)) 835 break; 836 err = 0; 837 break; 838 839 case PPPIOCSCOMPRESS: 840 { 841 struct ppp_option_data data; 842 if (copy_from_user(&data, argp, sizeof(data))) 843 err = -EFAULT; 844 else 845 err = ppp_set_compress(ppp, &data); 846 break; 847 } 848 case PPPIOCGUNIT: 849 if (put_user(ppp->file.index, p)) 850 break; 851 err = 0; 852 break; 853 854 case PPPIOCSDEBUG: 855 if (get_user(val, p)) 856 break; 857 ppp->debug = val; 858 err = 0; 859 break; 860 861 case PPPIOCGDEBUG: 862 if (put_user(ppp->debug, p)) 863 break; 864 err = 0; 865 break; 866 867 case PPPIOCGIDLE32: 868 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 869 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; 870 if (copy_to_user(argp, &idle32, sizeof(idle32))) 871 break; 872 err = 0; 873 break; 874 875 case PPPIOCGIDLE64: 876 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 877 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; 878 if (copy_to_user(argp, &idle64, sizeof(idle64))) 879 break; 880 err = 0; 881 break; 882 883 case PPPIOCSMAXCID: 884 if (get_user(val, p)) 885 break; 886 val2 = 15; 887 if ((val >> 16) != 0) { 888 val2 = val >> 16; 889 val &= 0xffff; 890 } 891 vj = slhc_init(val2+1, val+1); 892 if (IS_ERR(vj)) { 893 err = PTR_ERR(vj); 894 break; 895 } 896 ppp_lock(ppp); 897 if (ppp->vj) 898 slhc_free(ppp->vj); 899 ppp->vj = vj; 900 ppp_unlock(ppp); 901 err = 0; 902 break; 903 904 case PPPIOCGNPMODE: 905 case PPPIOCSNPMODE: 906 if (copy_from_user(&npi, argp, sizeof(npi))) 907 break; 908 err = proto_to_npindex(npi.protocol); 909 if (err < 0) 910 break; 911 i = err; 912 if (cmd == PPPIOCGNPMODE) { 913 err = -EFAULT; 914 npi.mode = ppp->npmode[i]; 915 if (copy_to_user(argp, &npi, sizeof(npi))) 916 break; 917 } else { 918 ppp->npmode[i] = npi.mode; 919 /* we may be able to transmit more packets now (??) */ 920 netif_wake_queue(ppp->dev); 921 } 922 err = 0; 923 break; 924 925 #ifdef CONFIG_PPP_FILTER 926 case PPPIOCSPASS: 927 case PPPIOCSACTIVE: 928 { 929 struct bpf_prog *filter = ppp_get_filter(argp); 930 struct bpf_prog **which; 931 932 if (IS_ERR(filter)) { 933 err = PTR_ERR(filter); 934 break; 935 } 936 if (cmd == PPPIOCSPASS) 937 which = &ppp->pass_filter; 938 else 939 which = &ppp->active_filter; 940 ppp_lock(ppp); 941 if (*which) 942 bpf_prog_destroy(*which); 943 *which = filter; 944 ppp_unlock(ppp); 945 err = 0; 946 break; 947 } 948 #endif /* CONFIG_PPP_FILTER */ 949 950 #ifdef CONFIG_PPP_MULTILINK 951 case PPPIOCSMRRU: 952 if (get_user(val, p)) 953 break; 954 ppp_recv_lock(ppp); 955 ppp->mrru = val; 956 ppp_recv_unlock(ppp); 957 err = 0; 958 break; 959 #endif /* CONFIG_PPP_MULTILINK */ 960 961 default: 962 err = -ENOTTY; 963 } 964 965 out: 966 mutex_unlock(&ppp_mutex); 967 968 return err; 969 } 970 971 #ifdef CONFIG_COMPAT 972 struct ppp_option_data32 { 973 compat_uptr_t ptr; 974 u32 length; 975 compat_int_t transmit; 976 }; 977 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) 978 979 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 980 { 981 struct ppp_file *pf; 982 int err = -ENOIOCTLCMD; 983 void __user *argp = (void __user *)arg; 984 985 mutex_lock(&ppp_mutex); 986 987 pf = file->private_data; 988 if (pf && pf->kind == INTERFACE) { 989 struct ppp *ppp = PF_TO_PPP(pf); 990 switch (cmd) { 991 #ifdef CONFIG_PPP_FILTER 992 case PPPIOCSPASS32: 993 case PPPIOCSACTIVE32: 994 { 995 struct bpf_prog *filter = compat_ppp_get_filter(argp); 996 struct bpf_prog **which; 997 998 if (IS_ERR(filter)) { 999 err = PTR_ERR(filter); 1000 break; 1001 } 1002 if (cmd == PPPIOCSPASS32) 1003 which = &ppp->pass_filter; 1004 else 1005 which = &ppp->active_filter; 1006 ppp_lock(ppp); 1007 if (*which) 1008 bpf_prog_destroy(*which); 1009 *which = filter; 1010 ppp_unlock(ppp); 1011 err = 0; 1012 break; 1013 } 1014 #endif /* CONFIG_PPP_FILTER */ 1015 case PPPIOCSCOMPRESS32: 1016 { 1017 struct ppp_option_data32 data32; 1018 if (copy_from_user(&data32, argp, sizeof(data32))) { 1019 err = -EFAULT; 1020 } else { 1021 struct ppp_option_data data = { 1022 .ptr = compat_ptr(data32.ptr), 1023 .length = data32.length, 1024 .transmit = data32.transmit 1025 }; 1026 err = ppp_set_compress(ppp, &data); 1027 } 1028 break; 1029 } 1030 } 1031 } 1032 mutex_unlock(&ppp_mutex); 1033 1034 /* all other commands have compatible arguments */ 1035 if (err == -ENOIOCTLCMD) 1036 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1037 1038 return err; 1039 } 1040 #endif 1041 1042 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 1043 struct file *file, unsigned int cmd, unsigned long arg) 1044 { 1045 int unit, err = -EFAULT; 1046 struct ppp *ppp; 1047 struct channel *chan; 1048 struct ppp_net *pn; 1049 int __user *p = (int __user *)arg; 1050 1051 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1052 return -EPERM; 1053 1054 switch (cmd) { 1055 case PPPIOCNEWUNIT: 1056 /* Create a new ppp unit */ 1057 if (get_user(unit, p)) 1058 break; 1059 err = ppp_create_interface(net, file, &unit); 1060 if (err < 0) 1061 break; 1062 1063 err = -EFAULT; 1064 if (put_user(unit, p)) 1065 break; 1066 err = 0; 1067 break; 1068 1069 case PPPIOCATTACH: 1070 /* Attach to an existing ppp unit */ 1071 if (get_user(unit, p)) 1072 break; 1073 err = -ENXIO; 1074 pn = ppp_pernet(net); 1075 mutex_lock(&pn->all_ppp_mutex); 1076 ppp = ppp_find_unit(pn, unit); 1077 if (ppp) { 1078 refcount_inc(&ppp->file.refcnt); 1079 file->private_data = &ppp->file; 1080 err = 0; 1081 } 1082 mutex_unlock(&pn->all_ppp_mutex); 1083 break; 1084 1085 case PPPIOCATTCHAN: 1086 if (get_user(unit, p)) 1087 break; 1088 err = -ENXIO; 1089 pn = ppp_pernet(net); 1090 spin_lock_bh(&pn->all_channels_lock); 1091 chan = ppp_find_channel(pn, unit); 1092 if (chan) { 1093 refcount_inc(&chan->file.refcnt); 1094 file->private_data = &chan->file; 1095 err = 0; 1096 } 1097 spin_unlock_bh(&pn->all_channels_lock); 1098 break; 1099 1100 default: 1101 err = -ENOTTY; 1102 } 1103 1104 return err; 1105 } 1106 1107 static const struct file_operations ppp_device_fops = { 1108 .owner = THIS_MODULE, 1109 .read = ppp_read, 1110 .write = ppp_write, 1111 .poll = ppp_poll, 1112 .unlocked_ioctl = ppp_ioctl, 1113 #ifdef CONFIG_COMPAT 1114 .compat_ioctl = ppp_compat_ioctl, 1115 #endif 1116 .open = ppp_open, 1117 .release = ppp_release, 1118 .llseek = noop_llseek, 1119 }; 1120 1121 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head); 1122 1123 static __net_init int ppp_init_net(struct net *net) 1124 { 1125 struct ppp_net *pn = net_generic(net, ppp_net_id); 1126 1127 idr_init(&pn->units_idr); 1128 mutex_init(&pn->all_ppp_mutex); 1129 1130 INIT_LIST_HEAD(&pn->all_channels); 1131 INIT_LIST_HEAD(&pn->new_channels); 1132 1133 spin_lock_init(&pn->all_channels_lock); 1134 1135 return 0; 1136 } 1137 1138 static __net_exit void ppp_exit_rtnl_net(struct net *net, 1139 struct list_head *dev_to_kill) 1140 { 1141 struct ppp_net *pn = net_generic(net, ppp_net_id); 1142 struct ppp *ppp; 1143 int id; 1144 1145 idr_for_each_entry(&pn->units_idr, ppp, id) 1146 ppp_nl_dellink(ppp->dev, dev_to_kill); 1147 } 1148 1149 static __net_exit void ppp_exit_net(struct net *net) 1150 { 1151 struct ppp_net *pn = net_generic(net, ppp_net_id); 1152 1153 mutex_destroy(&pn->all_ppp_mutex); 1154 idr_destroy(&pn->units_idr); 1155 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 1156 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 1157 } 1158 1159 static struct pernet_operations ppp_net_ops = { 1160 .init = ppp_init_net, 1161 .exit_rtnl = ppp_exit_rtnl_net, 1162 .exit = ppp_exit_net, 1163 .id = &ppp_net_id, 1164 .size = sizeof(struct ppp_net), 1165 }; 1166 1167 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 1168 { 1169 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1170 int ret; 1171 1172 mutex_lock(&pn->all_ppp_mutex); 1173 1174 if (unit < 0) { 1175 ret = unit_get(&pn->units_idr, ppp, 0); 1176 if (ret < 0) 1177 goto err; 1178 if (!ifname_is_set) { 1179 while (1) { 1180 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret); 1181 if (!netdev_name_in_use(ppp->ppp_net, ppp->dev->name)) 1182 break; 1183 unit_put(&pn->units_idr, ret); 1184 ret = unit_get(&pn->units_idr, ppp, ret + 1); 1185 if (ret < 0) 1186 goto err; 1187 } 1188 } 1189 } else { 1190 /* Caller asked for a specific unit number. Fail with -EEXIST 1191 * if unavailable. For backward compatibility, return -EEXIST 1192 * too if idr allocation fails; this makes pppd retry without 1193 * requesting a specific unit number. 1194 */ 1195 if (unit_find(&pn->units_idr, unit)) { 1196 ret = -EEXIST; 1197 goto err; 1198 } 1199 ret = unit_set(&pn->units_idr, ppp, unit); 1200 if (ret < 0) { 1201 /* Rewrite error for backward compatibility */ 1202 ret = -EEXIST; 1203 goto err; 1204 } 1205 } 1206 ppp->file.index = ret; 1207 1208 if (!ifname_is_set) 1209 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1210 1211 mutex_unlock(&pn->all_ppp_mutex); 1212 1213 ret = register_netdevice(ppp->dev); 1214 if (ret < 0) 1215 goto err_unit; 1216 1217 atomic_inc(&ppp_unit_count); 1218 1219 return 0; 1220 1221 err_unit: 1222 mutex_lock(&pn->all_ppp_mutex); 1223 unit_put(&pn->units_idr, ppp->file.index); 1224 err: 1225 mutex_unlock(&pn->all_ppp_mutex); 1226 1227 return ret; 1228 } 1229 1230 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1231 const struct ppp_config *conf) 1232 { 1233 struct ppp *ppp = netdev_priv(dev); 1234 int indx; 1235 int err; 1236 int cpu; 1237 1238 ppp->dev = dev; 1239 ppp->ppp_net = src_net; 1240 ppp->mru = PPP_MRU; 1241 ppp->owner = conf->file; 1242 1243 init_ppp_file(&ppp->file, INTERFACE); 1244 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1245 1246 for (indx = 0; indx < NUM_NP; ++indx) 1247 ppp->npmode[indx] = NPMODE_PASS; 1248 INIT_LIST_HEAD(&ppp->channels); 1249 spin_lock_init(&ppp->rlock); 1250 spin_lock_init(&ppp->wlock); 1251 1252 ppp->xmit_recursion = alloc_percpu(struct ppp_xmit_recursion); 1253 if (!ppp->xmit_recursion) { 1254 err = -ENOMEM; 1255 goto err1; 1256 } 1257 for_each_possible_cpu(cpu) { 1258 struct ppp_xmit_recursion *xmit_recursion; 1259 1260 xmit_recursion = per_cpu_ptr(ppp->xmit_recursion, cpu); 1261 xmit_recursion->owner = NULL; 1262 local_lock_init(&xmit_recursion->bh_lock); 1263 } 1264 1265 #ifdef CONFIG_PPP_MULTILINK 1266 ppp->minseq = -1; 1267 skb_queue_head_init(&ppp->mrq); 1268 #endif /* CONFIG_PPP_MULTILINK */ 1269 #ifdef CONFIG_PPP_FILTER 1270 ppp->pass_filter = NULL; 1271 ppp->active_filter = NULL; 1272 #endif /* CONFIG_PPP_FILTER */ 1273 1274 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1275 if (err < 0) 1276 goto err2; 1277 1278 conf->file->private_data = &ppp->file; 1279 1280 return 0; 1281 err2: 1282 free_percpu(ppp->xmit_recursion); 1283 err1: 1284 return err; 1285 } 1286 1287 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1288 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1289 }; 1290 1291 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1292 struct netlink_ext_ack *extack) 1293 { 1294 if (!data) 1295 return -EINVAL; 1296 1297 if (!data[IFLA_PPP_DEV_FD]) 1298 return -EINVAL; 1299 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1300 return -EBADF; 1301 1302 return 0; 1303 } 1304 1305 static int ppp_nl_newlink(struct net_device *dev, 1306 struct rtnl_newlink_params *params, 1307 struct netlink_ext_ack *extack) 1308 { 1309 struct net *link_net = rtnl_newlink_link_net(params); 1310 struct nlattr **data = params->data; 1311 struct nlattr **tb = params->tb; 1312 struct ppp_config conf = { 1313 .unit = -1, 1314 .ifname_is_set = true, 1315 }; 1316 struct file *file; 1317 int err; 1318 1319 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1320 if (!file) 1321 return -EBADF; 1322 1323 /* rtnl_lock is already held here, but ppp_create_interface() locks 1324 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1325 * possible deadlock due to lock order inversion, at the cost of 1326 * pushing the problem back to userspace. 1327 */ 1328 if (!mutex_trylock(&ppp_mutex)) { 1329 err = -EBUSY; 1330 goto out; 1331 } 1332 1333 if (file->f_op != &ppp_device_fops || file->private_data) { 1334 err = -EBADF; 1335 goto out_unlock; 1336 } 1337 1338 conf.file = file; 1339 1340 /* Don't use device name generated by the rtnetlink layer when ifname 1341 * isn't specified. Let ppp_dev_configure() set the device name using 1342 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1343 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1344 */ 1345 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME])) 1346 conf.ifname_is_set = false; 1347 1348 err = ppp_dev_configure(link_net, dev, &conf); 1349 1350 out_unlock: 1351 mutex_unlock(&ppp_mutex); 1352 out: 1353 fput(file); 1354 1355 return err; 1356 } 1357 1358 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1359 { 1360 unregister_netdevice_queue(dev, head); 1361 } 1362 1363 static size_t ppp_nl_get_size(const struct net_device *dev) 1364 { 1365 return 0; 1366 } 1367 1368 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1369 { 1370 return 0; 1371 } 1372 1373 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1374 { 1375 struct ppp *ppp = netdev_priv(dev); 1376 1377 return READ_ONCE(ppp->ppp_net); 1378 } 1379 1380 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1381 .kind = "ppp", 1382 .maxtype = IFLA_PPP_MAX, 1383 .policy = ppp_nl_policy, 1384 .priv_size = sizeof(struct ppp), 1385 .setup = ppp_setup, 1386 .validate = ppp_nl_validate, 1387 .newlink = ppp_nl_newlink, 1388 .dellink = ppp_nl_dellink, 1389 .get_size = ppp_nl_get_size, 1390 .fill_info = ppp_nl_fill_info, 1391 .get_link_net = ppp_nl_get_link_net, 1392 }; 1393 1394 #define PPP_MAJOR 108 1395 1396 /* Called at boot time if ppp is compiled into the kernel, 1397 or at module load time (from init_module) if compiled as a module. */ 1398 static int __init ppp_init(void) 1399 { 1400 int err; 1401 1402 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1403 1404 err = register_pernet_device(&ppp_net_ops); 1405 if (err) { 1406 pr_err("failed to register PPP pernet device (%d)\n", err); 1407 goto out; 1408 } 1409 1410 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1411 if (err) { 1412 pr_err("failed to register PPP device (%d)\n", err); 1413 goto out_net; 1414 } 1415 1416 err = class_register(&ppp_class); 1417 if (err) 1418 goto out_chrdev; 1419 1420 err = rtnl_link_register(&ppp_link_ops); 1421 if (err) { 1422 pr_err("failed to register rtnetlink PPP handler\n"); 1423 goto out_class; 1424 } 1425 1426 /* not a big deal if we fail here :-) */ 1427 device_create(&ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1428 1429 return 0; 1430 1431 out_class: 1432 class_unregister(&ppp_class); 1433 out_chrdev: 1434 unregister_chrdev(PPP_MAJOR, "ppp"); 1435 out_net: 1436 unregister_pernet_device(&ppp_net_ops); 1437 out: 1438 return err; 1439 } 1440 1441 /* 1442 * Network interface unit routines. 1443 */ 1444 static netdev_tx_t 1445 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1446 { 1447 struct ppp *ppp = netdev_priv(dev); 1448 int npi, proto; 1449 unsigned char *pp; 1450 1451 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1452 if (npi < 0) 1453 goto outf; 1454 1455 /* Drop, accept or reject the packet */ 1456 switch (ppp->npmode[npi]) { 1457 case NPMODE_PASS: 1458 break; 1459 case NPMODE_QUEUE: 1460 /* it would be nice to have a way to tell the network 1461 system to queue this one up for later. */ 1462 goto outf; 1463 case NPMODE_DROP: 1464 case NPMODE_ERROR: 1465 goto outf; 1466 } 1467 1468 /* Put the 2-byte PPP protocol number on the front, 1469 making sure there is room for the address and control fields. */ 1470 if (skb_cow_head(skb, PPP_HDRLEN)) 1471 goto outf; 1472 1473 pp = skb_push(skb, 2); 1474 proto = npindex_to_proto[npi]; 1475 put_unaligned_be16(proto, pp); 1476 1477 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1478 ppp_xmit_process(ppp, skb); 1479 1480 return NETDEV_TX_OK; 1481 1482 outf: 1483 kfree_skb(skb); 1484 ++dev->stats.tx_dropped; 1485 return NETDEV_TX_OK; 1486 } 1487 1488 static int 1489 ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 1490 void __user *addr, int cmd) 1491 { 1492 struct ppp *ppp = netdev_priv(dev); 1493 int err = -EFAULT; 1494 struct ppp_stats stats; 1495 struct ppp_comp_stats cstats; 1496 char *vers; 1497 1498 switch (cmd) { 1499 case SIOCGPPPSTATS: 1500 ppp_get_stats(ppp, &stats); 1501 if (copy_to_user(addr, &stats, sizeof(stats))) 1502 break; 1503 err = 0; 1504 break; 1505 1506 case SIOCGPPPCSTATS: 1507 memset(&cstats, 0, sizeof(cstats)); 1508 if (ppp->xc_state) 1509 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1510 if (ppp->rc_state) 1511 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1512 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1513 break; 1514 err = 0; 1515 break; 1516 1517 case SIOCGPPPVER: 1518 vers = PPP_VERSION; 1519 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1520 break; 1521 err = 0; 1522 break; 1523 1524 default: 1525 err = -EINVAL; 1526 } 1527 1528 return err; 1529 } 1530 1531 static void 1532 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1533 { 1534 stats64->rx_errors = dev->stats.rx_errors; 1535 stats64->tx_errors = dev->stats.tx_errors; 1536 stats64->rx_dropped = dev->stats.rx_dropped; 1537 stats64->tx_dropped = dev->stats.tx_dropped; 1538 stats64->rx_length_errors = dev->stats.rx_length_errors; 1539 dev_fetch_sw_netstats(stats64, dev->tstats); 1540 } 1541 1542 static int ppp_dev_init(struct net_device *dev) 1543 { 1544 struct ppp *ppp; 1545 1546 netdev_lockdep_set_classes(dev); 1547 1548 ppp = netdev_priv(dev); 1549 /* Let the netdevice take a reference on the ppp file. This ensures 1550 * that ppp_destroy_interface() won't run before the device gets 1551 * unregistered. 1552 */ 1553 refcount_inc(&ppp->file.refcnt); 1554 1555 return 0; 1556 } 1557 1558 static void ppp_dev_uninit(struct net_device *dev) 1559 { 1560 struct ppp *ppp = netdev_priv(dev); 1561 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1562 1563 ppp_lock(ppp); 1564 ppp->closing = 1; 1565 ppp_unlock(ppp); 1566 1567 mutex_lock(&pn->all_ppp_mutex); 1568 unit_put(&pn->units_idr, ppp->file.index); 1569 mutex_unlock(&pn->all_ppp_mutex); 1570 1571 ppp->owner = NULL; 1572 1573 ppp->file.dead = 1; 1574 wake_up_interruptible(&ppp->file.rwait); 1575 } 1576 1577 static void ppp_dev_priv_destructor(struct net_device *dev) 1578 { 1579 struct ppp *ppp; 1580 1581 ppp = netdev_priv(dev); 1582 ppp_release_interface(ppp); 1583 } 1584 1585 static int ppp_fill_forward_path(struct net_device_path_ctx *ctx, 1586 struct net_device_path *path) 1587 { 1588 struct ppp *ppp = netdev_priv(ctx->dev); 1589 struct ppp_channel *chan; 1590 struct channel *pch; 1591 1592 if (ppp->flags & SC_MULTILINK) 1593 return -EOPNOTSUPP; 1594 1595 pch = list_first_or_null_rcu(&ppp->channels, struct channel, clist); 1596 if (!pch) 1597 return -ENODEV; 1598 1599 chan = pch->chan; 1600 if (!chan->ops->fill_forward_path) 1601 return -EOPNOTSUPP; 1602 1603 return chan->ops->fill_forward_path(ctx, path, chan); 1604 } 1605 1606 static const struct net_device_ops ppp_netdev_ops = { 1607 .ndo_init = ppp_dev_init, 1608 .ndo_uninit = ppp_dev_uninit, 1609 .ndo_start_xmit = ppp_start_xmit, 1610 .ndo_siocdevprivate = ppp_net_siocdevprivate, 1611 .ndo_get_stats64 = ppp_get_stats64, 1612 .ndo_fill_forward_path = ppp_fill_forward_path, 1613 }; 1614 1615 static const struct device_type ppp_type = { 1616 .name = "ppp", 1617 }; 1618 1619 static void ppp_setup(struct net_device *dev) 1620 { 1621 dev->netdev_ops = &ppp_netdev_ops; 1622 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1623 1624 dev->lltx = true; 1625 1626 dev->hard_header_len = PPP_HDRLEN; 1627 dev->mtu = PPP_MRU; 1628 dev->addr_len = 0; 1629 dev->tx_queue_len = 3; 1630 dev->type = ARPHRD_PPP; 1631 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1632 dev->priv_destructor = ppp_dev_priv_destructor; 1633 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; 1634 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST; 1635 dev->hw_features = dev->features; 1636 netif_keep_dst(dev); 1637 } 1638 1639 /* 1640 * Transmit-side routines. 1641 */ 1642 1643 /* Called to do any work queued up on the transmit side that can now be done */ 1644 static void ppp_xmit_flush(struct ppp *ppp) 1645 { 1646 struct sk_buff *skb; 1647 1648 while ((skb = skb_dequeue(&ppp->file.xq))) { 1649 if (unlikely(!ppp_push(ppp, skb))) { 1650 skb_queue_head(&ppp->file.xq, skb); 1651 return; 1652 } 1653 } 1654 /* If there's no work left to do, tell the core net code that we can 1655 * accept some more. 1656 */ 1657 netif_wake_queue(ppp->dev); 1658 } 1659 1660 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1661 { 1662 ppp_xmit_lock(ppp); 1663 if (unlikely(ppp->closing)) { 1664 kfree_skb(skb); 1665 goto out; 1666 } 1667 if (unlikely(ppp_prepare_tx_skb(ppp, &skb))) 1668 goto out; 1669 /* Fastpath: No backlog, just send the new skb. */ 1670 if (likely(skb_queue_empty(&ppp->file.xq))) { 1671 if (unlikely(!ppp_push(ppp, skb))) { 1672 skb_queue_tail(&ppp->file.xq, skb); 1673 netif_stop_queue(ppp->dev); 1674 } 1675 goto out; 1676 } 1677 1678 /* Slowpath: Enqueue the new skb and process backlog */ 1679 skb_queue_tail(&ppp->file.xq, skb); 1680 ppp_xmit_flush(ppp); 1681 out: 1682 ppp_xmit_unlock(ppp); 1683 } 1684 1685 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1686 { 1687 struct ppp_xmit_recursion *xmit_recursion; 1688 1689 local_bh_disable(); 1690 1691 xmit_recursion = this_cpu_ptr(ppp->xmit_recursion); 1692 if (xmit_recursion->owner == current) 1693 goto err; 1694 local_lock_nested_bh(&ppp->xmit_recursion->bh_lock); 1695 xmit_recursion->owner = current; 1696 1697 __ppp_xmit_process(ppp, skb); 1698 1699 xmit_recursion->owner = NULL; 1700 local_unlock_nested_bh(&ppp->xmit_recursion->bh_lock); 1701 local_bh_enable(); 1702 1703 return; 1704 1705 err: 1706 local_bh_enable(); 1707 1708 kfree_skb(skb); 1709 1710 if (net_ratelimit()) 1711 netdev_err(ppp->dev, "recursion detected\n"); 1712 } 1713 1714 static inline struct sk_buff * 1715 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1716 { 1717 struct sk_buff *new_skb; 1718 int len; 1719 int new_skb_size = ppp->dev->mtu + 1720 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1721 int compressor_skb_size = ppp->dev->mtu + 1722 ppp->xcomp->comp_extra + PPP_HDRLEN; 1723 1724 if (skb_linearize(skb)) 1725 return NULL; 1726 1727 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1728 if (!new_skb) { 1729 if (net_ratelimit()) 1730 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1731 return NULL; 1732 } 1733 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1734 skb_reserve(new_skb, 1735 ppp->dev->hard_header_len - PPP_HDRLEN); 1736 1737 /* compressor still expects A/C bytes in hdr */ 1738 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1739 new_skb->data, skb->len + 2, 1740 compressor_skb_size); 1741 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1742 consume_skb(skb); 1743 skb = new_skb; 1744 skb_put(skb, len); 1745 skb_pull(skb, 2); /* pull off A/C bytes */ 1746 } else if (len == 0) { 1747 /* didn't compress, or CCP not up yet */ 1748 consume_skb(new_skb); 1749 new_skb = skb; 1750 } else { 1751 /* 1752 * (len < 0) 1753 * MPPE requires that we do not send unencrypted 1754 * frames. The compressor will return -1 if we 1755 * should drop the frame. We cannot simply test 1756 * the compress_proto because MPPE and MPPC share 1757 * the same number. 1758 */ 1759 if (net_ratelimit()) 1760 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1761 consume_skb(new_skb); 1762 new_skb = NULL; 1763 } 1764 return new_skb; 1765 } 1766 1767 /* 1768 * Compress and prepare to send a frame. 1769 * The caller should have locked the xmit path. 1770 * Returns 1 if the skb was consumed, 0 if it can be passed to ppp_push(). 1771 * @pskb is updated if a compressor is in use. 1772 */ 1773 static int 1774 ppp_prepare_tx_skb(struct ppp *ppp, struct sk_buff **pskb) 1775 { 1776 struct sk_buff *skb = *pskb; 1777 int proto = PPP_PROTO(skb); 1778 struct sk_buff *new_skb; 1779 int len; 1780 unsigned char *cp; 1781 1782 skb->dev = ppp->dev; 1783 1784 if (proto < 0x8000) { 1785 #ifdef CONFIG_PPP_FILTER 1786 /* check if the packet passes the pass and active filters. 1787 * See comment for PPP_FILTER_OUTBOUND_TAG above. 1788 */ 1789 *(__be16 *)skb_push(skb, 2) = htons(PPP_FILTER_OUTBOUND_TAG); 1790 if (ppp->pass_filter && 1791 bpf_prog_run(ppp->pass_filter, skb) == 0) { 1792 if (ppp->debug & 1) 1793 netdev_printk(KERN_DEBUG, ppp->dev, 1794 "PPP: outbound frame " 1795 "not passed\n"); 1796 kfree_skb(skb); 1797 return 1; 1798 } 1799 /* if this packet passes the active filter, record the time */ 1800 if (!(ppp->active_filter && 1801 bpf_prog_run(ppp->active_filter, skb) == 0)) 1802 ppp->last_xmit = jiffies; 1803 skb_pull(skb, 2); 1804 #else 1805 /* for data packets, record the time */ 1806 ppp->last_xmit = jiffies; 1807 #endif /* CONFIG_PPP_FILTER */ 1808 } 1809 1810 dev_sw_netstats_tx_add(ppp->dev, 1, skb->len - PPP_PROTO_LEN); 1811 1812 switch (proto) { 1813 case PPP_IP: 1814 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1815 break; 1816 1817 if (skb_linearize(skb)) 1818 goto drop; 1819 1820 /* try to do VJ TCP header compression */ 1821 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1822 GFP_ATOMIC); 1823 if (!new_skb) { 1824 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1825 goto drop; 1826 } 1827 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1828 cp = skb->data + 2; 1829 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1830 new_skb->data + 2, &cp, 1831 !(ppp->flags & SC_NO_TCP_CCID)); 1832 if (cp == skb->data + 2) { 1833 /* didn't compress */ 1834 consume_skb(new_skb); 1835 } else { 1836 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1837 proto = PPP_VJC_COMP; 1838 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1839 } else { 1840 proto = PPP_VJC_UNCOMP; 1841 cp[0] = skb->data[2]; 1842 } 1843 consume_skb(skb); 1844 skb = new_skb; 1845 *pskb = skb; 1846 cp = skb_put(skb, len + 2); 1847 cp[0] = 0; 1848 cp[1] = proto; 1849 } 1850 break; 1851 1852 case PPP_CCP: 1853 /* peek at outbound CCP frames */ 1854 ppp_ccp_peek(ppp, skb, 0); 1855 break; 1856 } 1857 1858 /* try to do packet compression */ 1859 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1860 proto != PPP_LCP && proto != PPP_CCP) { 1861 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1862 if (net_ratelimit()) 1863 netdev_err(ppp->dev, 1864 "ppp: compression required but " 1865 "down - pkt dropped.\n"); 1866 goto drop; 1867 } 1868 new_skb = pad_compress_skb(ppp, skb); 1869 if (!new_skb) 1870 goto drop; 1871 skb = new_skb; 1872 *pskb = skb; 1873 } 1874 1875 /* 1876 * If we are waiting for traffic (demand dialling), 1877 * queue it up for pppd to receive. 1878 */ 1879 if (ppp->flags & SC_LOOP_TRAFFIC) { 1880 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1881 goto drop; 1882 skb_queue_tail(&ppp->file.rq, skb); 1883 wake_up_interruptible(&ppp->file.rwait); 1884 return 1; 1885 } 1886 1887 return 0; 1888 1889 drop: 1890 kfree_skb(skb); 1891 ++ppp->dev->stats.tx_errors; 1892 return 1; 1893 } 1894 1895 /* 1896 * Try to send the frame. 1897 * The caller should have the xmit path locked. 1898 * Returns 1 if the skb was consumed, 0 if not. 1899 */ 1900 static int 1901 ppp_push(struct ppp *ppp, struct sk_buff *skb) 1902 { 1903 struct list_head *list; 1904 struct channel *pch; 1905 1906 list = &ppp->channels; 1907 if (list_empty(list)) { 1908 /* nowhere to send the packet, just drop it */ 1909 kfree_skb(skb); 1910 return 1; 1911 } 1912 1913 if ((ppp->flags & SC_MULTILINK) == 0) { 1914 struct ppp_channel *chan; 1915 int ret; 1916 /* not doing multilink: send it down the first channel */ 1917 list = list->next; 1918 pch = list_entry(list, struct channel, clist); 1919 1920 spin_lock(&pch->downl); 1921 chan = pch->chan; 1922 if (unlikely(!chan->direct_xmit && skb_linearize(skb))) { 1923 /* channel requires a linear skb but linearization 1924 * failed 1925 */ 1926 kfree_skb(skb); 1927 ret = 1; 1928 goto out; 1929 } 1930 1931 ret = chan->ops->start_xmit(chan, skb); 1932 1933 out: 1934 spin_unlock(&pch->downl); 1935 return ret; 1936 } 1937 1938 #ifdef CONFIG_PPP_MULTILINK 1939 /* Multilink: fragment the packet over as many links 1940 as can take the packet at the moment. */ 1941 if (!ppp_mp_explode(ppp, skb)) 1942 return 0; 1943 #endif /* CONFIG_PPP_MULTILINK */ 1944 1945 kfree_skb(skb); 1946 return 1; 1947 } 1948 1949 #ifdef CONFIG_PPP_MULTILINK 1950 static bool mp_protocol_compress __read_mostly = true; 1951 module_param(mp_protocol_compress, bool, 0644); 1952 MODULE_PARM_DESC(mp_protocol_compress, 1953 "compress protocol id in multilink fragments"); 1954 1955 /* 1956 * Divide a packet to be transmitted into fragments and 1957 * send them out the individual links. 1958 */ 1959 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1960 { 1961 int len, totlen; 1962 int i, bits, hdrlen, mtu; 1963 int flen; 1964 int navail, nfree, nzero; 1965 int nbigger; 1966 int totspeed; 1967 int totfree; 1968 unsigned char *p, *q; 1969 struct list_head *list; 1970 struct channel *pch; 1971 struct sk_buff *frag; 1972 struct ppp_channel *chan; 1973 1974 totspeed = 0; /*total bitrate of the bundle*/ 1975 nfree = 0; /* # channels which have no packet already queued */ 1976 navail = 0; /* total # of usable channels (not deregistered) */ 1977 nzero = 0; /* number of channels with zero speed associated*/ 1978 totfree = 0; /*total # of channels available and 1979 *having no queued packets before 1980 *starting the fragmentation*/ 1981 1982 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1983 i = 0; 1984 list_for_each_entry(pch, &ppp->channels, clist) { 1985 pch->avail = 1; 1986 navail++; 1987 pch->speed = pch->chan->speed; 1988 1989 if (skb_queue_empty(&pch->file.xq) || !pch->had_frag) { 1990 if (pch->speed == 0) 1991 nzero++; 1992 else 1993 totspeed += pch->speed; 1994 1995 pch->avail = 2; 1996 ++nfree; 1997 ++totfree; 1998 } 1999 if (!pch->had_frag && i < ppp->nxchan) 2000 ppp->nxchan = i; 2001 2002 ++i; 2003 } 2004 /* 2005 * Don't start sending this packet unless at least half of 2006 * the channels are free. This gives much better TCP 2007 * performance if we have a lot of channels. 2008 */ 2009 if (nfree == 0 || nfree < navail / 2) 2010 return 0; /* can't take now, leave it in transmit queue */ 2011 2012 /* Do protocol field compression */ 2013 if (skb_linearize(skb)) 2014 goto err_linearize; 2015 p = skb->data; 2016 len = skb->len; 2017 if (*p == 0 && mp_protocol_compress) { 2018 ++p; 2019 --len; 2020 } 2021 2022 totlen = len; 2023 nbigger = len % nfree; 2024 2025 /* skip to the channel after the one we last used 2026 and start at that one */ 2027 list = &ppp->channels; 2028 for (i = 0; i < ppp->nxchan; ++i) { 2029 list = list->next; 2030 if (list == &ppp->channels) { 2031 i = 0; 2032 break; 2033 } 2034 } 2035 2036 /* create a fragment for each channel */ 2037 bits = B; 2038 while (len > 0) { 2039 list = list->next; 2040 if (list == &ppp->channels) { 2041 i = 0; 2042 continue; 2043 } 2044 pch = list_entry(list, struct channel, clist); 2045 ++i; 2046 if (!pch->avail) 2047 continue; 2048 2049 /* 2050 * Skip this channel if it has a fragment pending already and 2051 * we haven't given a fragment to all of the free channels. 2052 */ 2053 if (pch->avail == 1) { 2054 if (nfree > 0) 2055 continue; 2056 } else { 2057 pch->avail = 1; 2058 } 2059 2060 spin_lock(&pch->downl); 2061 /* 2062 *if the channel speed is not set divide 2063 *the packet evenly among the free channels; 2064 *otherwise divide it according to the speed 2065 *of the channel we are going to transmit on 2066 */ 2067 flen = len; 2068 if (nfree > 0) { 2069 if (pch->speed == 0) { 2070 flen = len/nfree; 2071 if (nbigger > 0) { 2072 flen++; 2073 nbigger--; 2074 } 2075 } else { 2076 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 2077 ((totspeed*totfree)/pch->speed)) - hdrlen; 2078 if (nbigger > 0) { 2079 flen += ((totfree - nzero)*pch->speed)/totspeed; 2080 nbigger -= ((totfree - nzero)*pch->speed)/ 2081 totspeed; 2082 } 2083 } 2084 nfree--; 2085 } 2086 2087 /* 2088 *check if we are on the last channel or 2089 *we exceded the length of the data to 2090 *fragment 2091 */ 2092 if ((nfree <= 0) || (flen > len)) 2093 flen = len; 2094 /* 2095 *it is not worth to tx on slow channels: 2096 *in that case from the resulting flen according to the 2097 *above formula will be equal or less than zero. 2098 *Skip the channel in this case 2099 */ 2100 if (flen <= 0) { 2101 pch->avail = 2; 2102 spin_unlock(&pch->downl); 2103 continue; 2104 } 2105 2106 /* 2107 * hdrlen includes the 2-byte PPP protocol field, but the 2108 * MTU counts only the payload excluding the protocol field. 2109 * (RFC1661 Section 2) 2110 */ 2111 mtu = pch->chan->mtu - (hdrlen - 2); 2112 if (mtu < 4) 2113 mtu = 4; 2114 if (flen > mtu) 2115 flen = mtu; 2116 if (flen == len) 2117 bits |= E; 2118 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 2119 if (!frag) 2120 goto noskb; 2121 q = skb_put(frag, flen + hdrlen); 2122 2123 /* make the MP header */ 2124 put_unaligned_be16(PPP_MP, q); 2125 if (ppp->flags & SC_MP_XSHORTSEQ) { 2126 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 2127 q[3] = ppp->nxseq; 2128 } else { 2129 q[2] = bits; 2130 q[3] = ppp->nxseq >> 16; 2131 q[4] = ppp->nxseq >> 8; 2132 q[5] = ppp->nxseq; 2133 } 2134 2135 memcpy(q + hdrlen, p, flen); 2136 2137 /* try to send it down the channel */ 2138 chan = pch->chan; 2139 if (!skb_queue_empty(&pch->file.xq) || 2140 !chan->ops->start_xmit(chan, frag)) 2141 skb_queue_tail(&pch->file.xq, frag); 2142 pch->had_frag = 1; 2143 p += flen; 2144 len -= flen; 2145 ++ppp->nxseq; 2146 bits = 0; 2147 spin_unlock(&pch->downl); 2148 } 2149 ppp->nxchan = i; 2150 2151 return 1; 2152 2153 noskb: 2154 spin_unlock(&pch->downl); 2155 err_linearize: 2156 if (ppp->debug & 1) 2157 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 2158 ++ppp->dev->stats.tx_errors; 2159 ++ppp->nxseq; 2160 return 1; /* abandon the frame */ 2161 } 2162 #endif /* CONFIG_PPP_MULTILINK */ 2163 2164 /* Try to send data out on a channel */ 2165 static void __ppp_channel_push(struct channel *pch, struct ppp *ppp) 2166 { 2167 struct sk_buff *skb; 2168 2169 spin_lock(&pch->downl); 2170 if (pch->chan) { 2171 while (!skb_queue_empty(&pch->file.xq)) { 2172 skb = skb_dequeue(&pch->file.xq); 2173 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2174 /* put the packet back and try again later */ 2175 skb_queue_head(&pch->file.xq, skb); 2176 break; 2177 } 2178 } 2179 } else { 2180 /* channel got deregistered */ 2181 skb_queue_purge(&pch->file.xq); 2182 } 2183 spin_unlock(&pch->downl); 2184 /* see if there is anything from the attached unit to be sent */ 2185 if (skb_queue_empty(&pch->file.xq)) { 2186 if (ppp) { 2187 ppp_xmit_lock(ppp); 2188 if (!ppp->closing) 2189 ppp_xmit_flush(ppp); 2190 ppp_xmit_unlock(ppp); 2191 } 2192 } 2193 } 2194 2195 static void ppp_channel_push(struct channel *pch) 2196 { 2197 struct ppp_xmit_recursion *xmit_recursion; 2198 struct ppp *ppp; 2199 2200 rcu_read_lock_bh(); 2201 ppp = rcu_dereference_bh(pch->ppp); 2202 if (ppp) { 2203 xmit_recursion = this_cpu_ptr(ppp->xmit_recursion); 2204 local_lock_nested_bh(&ppp->xmit_recursion->bh_lock); 2205 xmit_recursion->owner = current; 2206 __ppp_channel_push(pch, ppp); 2207 xmit_recursion->owner = NULL; 2208 local_unlock_nested_bh(&ppp->xmit_recursion->bh_lock); 2209 } else { 2210 __ppp_channel_push(pch, NULL); 2211 } 2212 rcu_read_unlock_bh(); 2213 } 2214 2215 /* 2216 * Receive-side routines. 2217 */ 2218 2219 struct ppp_mp_skb_parm { 2220 u32 sequence; 2221 u8 BEbits; 2222 }; 2223 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2224 2225 static inline void 2226 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2227 { 2228 ppp_recv_lock(ppp); 2229 if (!ppp->closing) 2230 ppp_receive_frame(ppp, skb, pch); 2231 else 2232 kfree_skb(skb); 2233 ppp_recv_unlock(ppp); 2234 } 2235 2236 /** 2237 * __ppp_decompress_proto - Decompress protocol field, slim version. 2238 * @skb: Socket buffer where protocol field should be decompressed. It must have 2239 * at least 1 byte of head room and 1 byte of linear data. First byte of 2240 * data must be a protocol field byte. 2241 * 2242 * Decompress protocol field in PPP header if it's compressed, e.g. when 2243 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2244 * length are done in this function. 2245 */ 2246 static void __ppp_decompress_proto(struct sk_buff *skb) 2247 { 2248 if (skb->data[0] & 0x01) 2249 *(u8 *)skb_push(skb, 1) = 0x00; 2250 } 2251 2252 /** 2253 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2254 * @skb: Socket buffer where protocol field should be decompressed. First byte 2255 * of data must be a protocol field byte. 2256 * 2257 * Decompress protocol field in PPP header if it's compressed, e.g. when 2258 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2259 * sure that skb data room is sufficient for Protocol field, before and after 2260 * decompression. 2261 * 2262 * Return: true - decompressed successfully, false - not enough room in skb. 2263 */ 2264 static bool ppp_decompress_proto(struct sk_buff *skb) 2265 { 2266 /* At least one byte should be present (if protocol is compressed) */ 2267 if (!pskb_may_pull(skb, 1)) 2268 return false; 2269 2270 __ppp_decompress_proto(skb); 2271 2272 /* Protocol field should occupy 2 bytes when not compressed */ 2273 return pskb_may_pull(skb, 2); 2274 } 2275 2276 /* Attempt to handle a frame via. a bridged channel, if one exists. 2277 * If the channel is bridged, the frame is consumed by the bridge. 2278 * If not, the caller must handle the frame by normal recv mechanisms. 2279 * Returns true if the frame is consumed, false otherwise. 2280 */ 2281 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) 2282 { 2283 struct channel *pchb; 2284 2285 rcu_read_lock(); 2286 pchb = rcu_dereference(pch->bridge); 2287 if (!pchb) 2288 goto out_rcu; 2289 2290 spin_lock_bh(&pchb->downl); 2291 if (!pchb->chan) { 2292 /* channel got unregistered */ 2293 kfree_skb(skb); 2294 goto outl; 2295 } 2296 2297 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); 2298 if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) 2299 kfree_skb(skb); 2300 2301 outl: 2302 spin_unlock_bh(&pchb->downl); 2303 out_rcu: 2304 rcu_read_unlock(); 2305 2306 /* If pchb is set then we've consumed the packet */ 2307 return !!pchb; 2308 } 2309 2310 void 2311 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2312 { 2313 struct channel *pch = chan->ppp; 2314 struct ppp *ppp; 2315 int proto; 2316 2317 if (!pch) { 2318 kfree_skb(skb); 2319 return; 2320 } 2321 2322 /* If the channel is bridged, transmit via. bridge */ 2323 if (ppp_channel_bridge_input(pch, skb)) 2324 return; 2325 2326 rcu_read_lock_bh(); 2327 ppp = rcu_dereference_bh(pch->ppp); 2328 if (!ppp_decompress_proto(skb)) { 2329 kfree_skb(skb); 2330 if (ppp) { 2331 ++ppp->dev->stats.rx_length_errors; 2332 ppp_receive_error(ppp); 2333 } 2334 goto done; 2335 } 2336 2337 proto = PPP_PROTO(skb); 2338 if (!ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2339 /* put it on the channel queue */ 2340 skb_queue_tail(&pch->file.rq, skb); 2341 /* drop old frames if queue too long */ 2342 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2343 (skb = skb_dequeue(&pch->file.rq))) 2344 kfree_skb(skb); 2345 wake_up_interruptible(&pch->file.rwait); 2346 } else { 2347 ppp_do_recv(ppp, skb, pch); 2348 } 2349 2350 done: 2351 rcu_read_unlock_bh(); 2352 } 2353 2354 void 2355 ppp_input_error(struct ppp_channel *chan) 2356 { 2357 struct channel *pch = chan->ppp; 2358 struct ppp *ppp; 2359 2360 if (!pch) 2361 return; 2362 2363 rcu_read_lock_bh(); 2364 ppp = rcu_dereference_bh(pch->ppp); 2365 if (ppp) { 2366 ppp_recv_lock(ppp); 2367 ppp_receive_error(ppp); 2368 ppp_recv_unlock(ppp); 2369 } 2370 rcu_read_unlock_bh(); 2371 } 2372 2373 /* 2374 * We come in here to process a received frame. 2375 * The receive side of the ppp unit is locked. 2376 */ 2377 static void 2378 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2379 { 2380 skb_checksum_complete_unset(skb); 2381 #ifdef CONFIG_PPP_MULTILINK 2382 /* XXX do channel-level decompression here */ 2383 if (PPP_PROTO(skb) == PPP_MP) 2384 ppp_receive_mp_frame(ppp, skb, pch); 2385 else 2386 #endif /* CONFIG_PPP_MULTILINK */ 2387 ppp_receive_nonmp_frame(ppp, skb); 2388 } 2389 2390 static void 2391 ppp_receive_error(struct ppp *ppp) 2392 { 2393 ++ppp->dev->stats.rx_errors; 2394 if (ppp->vj) 2395 slhc_toss(ppp->vj); 2396 } 2397 2398 static void 2399 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2400 { 2401 struct sk_buff *ns; 2402 int proto, len, npi; 2403 2404 /* 2405 * Decompress the frame, if compressed. 2406 * Note that some decompressors need to see uncompressed frames 2407 * that come in as well as compressed frames. 2408 */ 2409 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2410 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2411 skb = ppp_decompress_frame(ppp, skb); 2412 2413 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2414 goto err; 2415 2416 /* At this point the "Protocol" field MUST be decompressed, either in 2417 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2418 */ 2419 proto = PPP_PROTO(skb); 2420 switch (proto) { 2421 case PPP_VJC_COMP: 2422 /* decompress VJ compressed packets */ 2423 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2424 goto err; 2425 2426 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2427 /* copy to a new sk_buff with more tailroom */ 2428 ns = dev_alloc_skb(skb->len + 128); 2429 if (!ns) { 2430 netdev_err(ppp->dev, "PPP: no memory " 2431 "(VJ decomp)\n"); 2432 goto err; 2433 } 2434 skb_reserve(ns, 2); 2435 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2436 consume_skb(skb); 2437 skb = ns; 2438 } 2439 else 2440 skb->ip_summed = CHECKSUM_NONE; 2441 2442 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2443 if (len <= 0) { 2444 netdev_printk(KERN_DEBUG, ppp->dev, 2445 "PPP: VJ decompression error\n"); 2446 goto err; 2447 } 2448 len += 2; 2449 if (len > skb->len) 2450 skb_put(skb, len - skb->len); 2451 else if (len < skb->len) 2452 skb_trim(skb, len); 2453 proto = PPP_IP; 2454 break; 2455 2456 case PPP_VJC_UNCOMP: 2457 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2458 goto err; 2459 2460 /* Until we fix the decompressor need to make sure 2461 * data portion is linear. 2462 */ 2463 if (!pskb_may_pull(skb, skb->len)) 2464 goto err; 2465 2466 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2467 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2468 goto err; 2469 } 2470 proto = PPP_IP; 2471 break; 2472 2473 case PPP_CCP: 2474 ppp_ccp_peek(ppp, skb, 1); 2475 break; 2476 } 2477 2478 dev_sw_netstats_rx_add(ppp->dev, skb->len - PPP_PROTO_LEN); 2479 2480 npi = proto_to_npindex(proto); 2481 if (npi < 0) { 2482 /* control or unknown frame - pass it to pppd */ 2483 skb_queue_tail(&ppp->file.rq, skb); 2484 /* limit queue length by dropping old frames */ 2485 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2486 (skb = skb_dequeue(&ppp->file.rq))) 2487 kfree_skb(skb); 2488 /* wake up any process polling or blocking on read */ 2489 wake_up_interruptible(&ppp->file.rwait); 2490 2491 } else { 2492 /* network protocol frame - give it to the kernel */ 2493 2494 #ifdef CONFIG_PPP_FILTER 2495 if (ppp->pass_filter || ppp->active_filter) { 2496 if (skb_unclone(skb, GFP_ATOMIC)) 2497 goto err; 2498 /* Check if the packet passes the pass and active filters. 2499 * See comment for PPP_FILTER_INBOUND_TAG above. 2500 */ 2501 *(__be16 *)skb_push(skb, 2) = htons(PPP_FILTER_INBOUND_TAG); 2502 if (ppp->pass_filter && 2503 bpf_prog_run(ppp->pass_filter, skb) == 0) { 2504 if (ppp->debug & 1) 2505 netdev_printk(KERN_DEBUG, ppp->dev, 2506 "PPP: inbound frame " 2507 "not passed\n"); 2508 kfree_skb(skb); 2509 return; 2510 } 2511 if (!(ppp->active_filter && 2512 bpf_prog_run(ppp->active_filter, skb) == 0)) 2513 ppp->last_recv = jiffies; 2514 __skb_pull(skb, 2); 2515 } else 2516 #endif /* CONFIG_PPP_FILTER */ 2517 ppp->last_recv = jiffies; 2518 2519 if ((ppp->dev->flags & IFF_UP) == 0 || 2520 ppp->npmode[npi] != NPMODE_PASS) { 2521 kfree_skb(skb); 2522 } else { 2523 /* chop off protocol */ 2524 skb_pull_rcsum(skb, 2); 2525 skb->dev = ppp->dev; 2526 skb->protocol = htons(npindex_to_ethertype[npi]); 2527 skb_reset_mac_header(skb); 2528 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2529 dev_net(ppp->dev))); 2530 netif_rx(skb); 2531 } 2532 } 2533 return; 2534 2535 err: 2536 kfree_skb(skb); 2537 ppp_receive_error(ppp); 2538 } 2539 2540 static struct sk_buff * 2541 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2542 { 2543 int proto = PPP_PROTO(skb); 2544 struct sk_buff *ns; 2545 int len; 2546 2547 /* Until we fix all the decompressor's need to make sure 2548 * data portion is linear. 2549 */ 2550 if (!pskb_may_pull(skb, skb->len)) 2551 goto err; 2552 2553 if (proto == PPP_COMP) { 2554 int obuff_size; 2555 2556 switch(ppp->rcomp->compress_proto) { 2557 case CI_MPPE: 2558 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2559 break; 2560 default: 2561 obuff_size = ppp->mru + PPP_HDRLEN; 2562 break; 2563 } 2564 2565 ns = dev_alloc_skb(obuff_size); 2566 if (!ns) { 2567 netdev_err(ppp->dev, "ppp_decompress_frame: " 2568 "no memory\n"); 2569 goto err; 2570 } 2571 /* the decompressor still expects the A/C bytes in the hdr */ 2572 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2573 skb->len + 2, ns->data, obuff_size); 2574 if (len < 0) { 2575 /* Pass the compressed frame to pppd as an 2576 error indication. */ 2577 if (len == DECOMP_FATALERROR) 2578 ppp->rstate |= SC_DC_FERROR; 2579 kfree_skb(ns); 2580 goto err; 2581 } 2582 2583 consume_skb(skb); 2584 skb = ns; 2585 skb_put(skb, len); 2586 skb_pull(skb, 2); /* pull off the A/C bytes */ 2587 2588 /* Don't call __ppp_decompress_proto() here, but instead rely on 2589 * corresponding algo (mppe/bsd/deflate) to decompress it. 2590 */ 2591 } else { 2592 /* Uncompressed frame - pass to decompressor so it 2593 can update its dictionary if necessary. */ 2594 if (ppp->rcomp->incomp) 2595 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2596 skb->len + 2); 2597 } 2598 2599 return skb; 2600 2601 err: 2602 ppp->rstate |= SC_DC_ERROR; 2603 ppp_receive_error(ppp); 2604 return skb; 2605 } 2606 2607 #ifdef CONFIG_PPP_MULTILINK 2608 /* 2609 * Receive a multilink frame. 2610 * We put it on the reconstruction queue and then pull off 2611 * as many completed frames as we can. 2612 */ 2613 static void 2614 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2615 { 2616 u32 mask, seq; 2617 struct channel *ch; 2618 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2619 2620 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2621 goto err; /* no good, throw it away */ 2622 2623 /* Decode sequence number and begin/end bits */ 2624 if (ppp->flags & SC_MP_SHORTSEQ) { 2625 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2626 mask = 0xfff; 2627 } else { 2628 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2629 mask = 0xffffff; 2630 } 2631 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2632 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2633 2634 /* 2635 * Do protocol ID decompression on the first fragment of each packet. 2636 * We have to do that here, because ppp_receive_nonmp_frame() expects 2637 * decompressed protocol field. 2638 */ 2639 if (PPP_MP_CB(skb)->BEbits & B) 2640 __ppp_decompress_proto(skb); 2641 2642 /* 2643 * Expand sequence number to 32 bits, making it as close 2644 * as possible to ppp->minseq. 2645 */ 2646 seq |= ppp->minseq & ~mask; 2647 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2648 seq += mask + 1; 2649 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2650 seq -= mask + 1; /* should never happen */ 2651 PPP_MP_CB(skb)->sequence = seq; 2652 pch->lastseq = seq; 2653 2654 /* 2655 * If this packet comes before the next one we were expecting, 2656 * drop it. 2657 */ 2658 if (seq_before(seq, ppp->nextseq)) { 2659 kfree_skb(skb); 2660 ++ppp->dev->stats.rx_dropped; 2661 ppp_receive_error(ppp); 2662 return; 2663 } 2664 2665 /* 2666 * Reevaluate minseq, the minimum over all channels of the 2667 * last sequence number received on each channel. Because of 2668 * the increasing sequence number rule, we know that any fragment 2669 * before `minseq' which hasn't arrived is never going to arrive. 2670 * The list of channels can't change because we have the receive 2671 * side of the ppp unit locked. 2672 */ 2673 list_for_each_entry(ch, &ppp->channels, clist) { 2674 if (seq_before(ch->lastseq, seq)) 2675 seq = ch->lastseq; 2676 } 2677 if (seq_before(ppp->minseq, seq)) 2678 ppp->minseq = seq; 2679 2680 /* Put the fragment on the reconstruction queue */ 2681 ppp_mp_insert(ppp, skb); 2682 2683 /* If the queue is getting long, don't wait any longer for packets 2684 before the start of the queue. */ 2685 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2686 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2687 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2688 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2689 } 2690 2691 /* Pull completed packets off the queue and receive them. */ 2692 while ((skb = ppp_mp_reconstruct(ppp))) { 2693 if (pskb_may_pull(skb, 2)) 2694 ppp_receive_nonmp_frame(ppp, skb); 2695 else { 2696 ++ppp->dev->stats.rx_length_errors; 2697 kfree_skb(skb); 2698 ppp_receive_error(ppp); 2699 } 2700 } 2701 2702 return; 2703 2704 err: 2705 kfree_skb(skb); 2706 ppp_receive_error(ppp); 2707 } 2708 2709 /* 2710 * Insert a fragment on the MP reconstruction queue. 2711 * The queue is ordered by increasing sequence number. 2712 */ 2713 static void 2714 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2715 { 2716 struct sk_buff *p; 2717 struct sk_buff_head *list = &ppp->mrq; 2718 u32 seq = PPP_MP_CB(skb)->sequence; 2719 2720 /* N.B. we don't need to lock the list lock because we have the 2721 ppp unit receive-side lock. */ 2722 skb_queue_walk(list, p) { 2723 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2724 break; 2725 } 2726 __skb_queue_before(list, p, skb); 2727 } 2728 2729 /* 2730 * Reconstruct a packet from the MP fragment queue. 2731 * We go through increasing sequence numbers until we find a 2732 * complete packet, or we get to the sequence number for a fragment 2733 * which hasn't arrived but might still do so. 2734 */ 2735 static struct sk_buff * 2736 ppp_mp_reconstruct(struct ppp *ppp) 2737 { 2738 u32 seq = ppp->nextseq; 2739 u32 minseq = ppp->minseq; 2740 struct sk_buff_head *list = &ppp->mrq; 2741 struct sk_buff *p, *tmp; 2742 struct sk_buff *head, *tail; 2743 struct sk_buff *skb = NULL; 2744 int lost = 0, len = 0; 2745 2746 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2747 return NULL; 2748 head = __skb_peek(list); 2749 tail = NULL; 2750 skb_queue_walk_safe(list, p, tmp) { 2751 again: 2752 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2753 /* this can't happen, anyway ignore the skb */ 2754 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2755 "seq %u < %u\n", 2756 PPP_MP_CB(p)->sequence, seq); 2757 __skb_unlink(p, list); 2758 kfree_skb(p); 2759 continue; 2760 } 2761 if (PPP_MP_CB(p)->sequence != seq) { 2762 u32 oldseq; 2763 /* Fragment `seq' is missing. If it is after 2764 minseq, it might arrive later, so stop here. */ 2765 if (seq_after(seq, minseq)) 2766 break; 2767 /* Fragment `seq' is lost, keep going. */ 2768 lost = 1; 2769 oldseq = seq; 2770 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2771 minseq + 1: PPP_MP_CB(p)->sequence; 2772 2773 if (ppp->debug & 1) 2774 netdev_printk(KERN_DEBUG, ppp->dev, 2775 "lost frag %u..%u\n", 2776 oldseq, seq-1); 2777 2778 goto again; 2779 } 2780 2781 /* 2782 * At this point we know that all the fragments from 2783 * ppp->nextseq to seq are either present or lost. 2784 * Also, there are no complete packets in the queue 2785 * that have no missing fragments and end before this 2786 * fragment. 2787 */ 2788 2789 /* B bit set indicates this fragment starts a packet */ 2790 if (PPP_MP_CB(p)->BEbits & B) { 2791 head = p; 2792 lost = 0; 2793 len = 0; 2794 } 2795 2796 len += p->len; 2797 2798 /* Got a complete packet yet? */ 2799 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2800 (PPP_MP_CB(head)->BEbits & B)) { 2801 if (len > ppp->mrru + 2) { 2802 ++ppp->dev->stats.rx_length_errors; 2803 netdev_printk(KERN_DEBUG, ppp->dev, 2804 "PPP: reconstructed packet" 2805 " is too long (%d)\n", len); 2806 } else { 2807 tail = p; 2808 break; 2809 } 2810 ppp->nextseq = seq + 1; 2811 } 2812 2813 /* 2814 * If this is the ending fragment of a packet, 2815 * and we haven't found a complete valid packet yet, 2816 * we can discard up to and including this fragment. 2817 */ 2818 if (PPP_MP_CB(p)->BEbits & E) { 2819 struct sk_buff *tmp2; 2820 2821 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2822 if (ppp->debug & 1) 2823 netdev_printk(KERN_DEBUG, ppp->dev, 2824 "discarding frag %u\n", 2825 PPP_MP_CB(p)->sequence); 2826 __skb_unlink(p, list); 2827 kfree_skb(p); 2828 } 2829 head = skb_peek(list); 2830 if (!head) 2831 break; 2832 } 2833 ++seq; 2834 } 2835 2836 /* If we have a complete packet, copy it all into one skb. */ 2837 if (tail != NULL) { 2838 /* If we have discarded any fragments, 2839 signal a receive error. */ 2840 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2841 skb_queue_walk_safe(list, p, tmp) { 2842 if (p == head) 2843 break; 2844 if (ppp->debug & 1) 2845 netdev_printk(KERN_DEBUG, ppp->dev, 2846 "discarding frag %u\n", 2847 PPP_MP_CB(p)->sequence); 2848 __skb_unlink(p, list); 2849 kfree_skb(p); 2850 } 2851 2852 if (ppp->debug & 1) 2853 netdev_printk(KERN_DEBUG, ppp->dev, 2854 " missed pkts %u..%u\n", 2855 ppp->nextseq, 2856 PPP_MP_CB(head)->sequence-1); 2857 ++ppp->dev->stats.rx_dropped; 2858 ppp_receive_error(ppp); 2859 } 2860 2861 skb = head; 2862 if (head != tail) { 2863 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2864 p = skb_queue_next(list, head); 2865 __skb_unlink(skb, list); 2866 skb_queue_walk_from_safe(list, p, tmp) { 2867 __skb_unlink(p, list); 2868 *fragpp = p; 2869 p->next = NULL; 2870 fragpp = &p->next; 2871 2872 skb->len += p->len; 2873 skb->data_len += p->len; 2874 skb->truesize += p->truesize; 2875 2876 if (p == tail) 2877 break; 2878 } 2879 } else { 2880 __skb_unlink(skb, list); 2881 } 2882 2883 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2884 } 2885 2886 return skb; 2887 } 2888 #endif /* CONFIG_PPP_MULTILINK */ 2889 2890 /* 2891 * Channel interface. 2892 */ 2893 2894 /* Create a new, unattached ppp channel. */ 2895 int ppp_register_channel(struct ppp_channel *chan) 2896 { 2897 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2898 } 2899 2900 /* Create a new, unattached ppp channel for specified net. */ 2901 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2902 { 2903 struct channel *pch; 2904 struct ppp_net *pn; 2905 2906 pch = kzalloc_obj(struct channel); 2907 if (!pch) 2908 return -ENOMEM; 2909 2910 pn = ppp_pernet(net); 2911 2912 pch->chan = chan; 2913 pch->chan_net = get_net_track(net, &pch->ns_tracker, GFP_KERNEL); 2914 chan->ppp = pch; 2915 init_ppp_file(&pch->file, CHANNEL); 2916 pch->file.hdrlen = chan->hdrlen; 2917 #ifdef CONFIG_PPP_MULTILINK 2918 pch->lastseq = -1; 2919 #endif /* CONFIG_PPP_MULTILINK */ 2920 init_rwsem(&pch->chan_sem); 2921 spin_lock_init(&pch->downl); 2922 spin_lock_init(&pch->upl); 2923 2924 spin_lock_bh(&pn->all_channels_lock); 2925 pch->file.index = ++pn->last_channel_index; 2926 list_add(&pch->list, &pn->new_channels); 2927 atomic_inc(&channel_count); 2928 spin_unlock_bh(&pn->all_channels_lock); 2929 2930 return 0; 2931 } 2932 2933 /* 2934 * Return the index of a channel. 2935 */ 2936 int ppp_channel_index(struct ppp_channel *chan) 2937 { 2938 struct channel *pch = chan->ppp; 2939 2940 if (pch) 2941 return pch->file.index; 2942 return -1; 2943 } 2944 2945 /* 2946 * Return the PPP unit number to which a channel is connected. 2947 */ 2948 int ppp_unit_number(struct ppp_channel *chan) 2949 { 2950 struct channel *pch = chan->ppp; 2951 struct ppp *ppp; 2952 int unit = -1; 2953 2954 if (pch) { 2955 rcu_read_lock(); 2956 ppp = rcu_dereference(pch->ppp); 2957 if (ppp) 2958 unit = ppp->file.index; 2959 rcu_read_unlock(); 2960 } 2961 return unit; 2962 } 2963 2964 /* 2965 * Return the PPP device interface name of a channel. 2966 * Caller must hold RCU read lock. 2967 */ 2968 char *ppp_dev_name(struct ppp_channel *chan) 2969 { 2970 struct channel *pch = chan->ppp; 2971 char *name = NULL; 2972 struct ppp *ppp; 2973 2974 if (pch) { 2975 ppp = rcu_dereference(pch->ppp); 2976 if (ppp && ppp->dev) 2977 name = ppp->dev->name; 2978 } 2979 return name; 2980 } 2981 2982 2983 /* 2984 * Disconnect a channel from the generic layer. 2985 * This must be called in process context. 2986 */ 2987 void 2988 ppp_unregister_channel(struct ppp_channel *chan) 2989 { 2990 struct channel *pch = chan->ppp; 2991 struct ppp_net *pn; 2992 2993 if (!pch) 2994 return; /* should never happen */ 2995 2996 chan->ppp = NULL; 2997 2998 /* 2999 * This ensures that we have returned from any calls into 3000 * the channel's start_xmit or ioctl routine before we proceed. 3001 */ 3002 ppp_disconnect_channel(pch); 3003 down_write(&pch->chan_sem); 3004 spin_lock_bh(&pch->downl); 3005 pch->chan = NULL; 3006 spin_unlock_bh(&pch->downl); 3007 up_write(&pch->chan_sem); 3008 3009 pn = ppp_pernet(pch->chan_net); 3010 spin_lock_bh(&pn->all_channels_lock); 3011 list_del(&pch->list); 3012 spin_unlock_bh(&pn->all_channels_lock); 3013 3014 ppp_unbridge_channels(pch); 3015 3016 pch->file.dead = 1; 3017 wake_up_interruptible(&pch->file.rwait); 3018 3019 ppp_release_channel(pch); 3020 } 3021 3022 /* 3023 * Callback from a channel when it can accept more to transmit. 3024 * This should be called at BH/softirq level, not interrupt level. 3025 */ 3026 void 3027 ppp_output_wakeup(struct ppp_channel *chan) 3028 { 3029 struct channel *pch = chan->ppp; 3030 3031 if (!pch) 3032 return; 3033 ppp_channel_push(pch); 3034 } 3035 3036 /* 3037 * Compression control. 3038 */ 3039 3040 /* Process the PPPIOCSCOMPRESS ioctl. */ 3041 static int 3042 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 3043 { 3044 int err = -EFAULT; 3045 struct compressor *cp, *ocomp; 3046 void *state, *ostate; 3047 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 3048 3049 if (data->length > CCP_MAX_OPTION_LENGTH) 3050 goto out; 3051 if (copy_from_user(ccp_option, data->ptr, data->length)) 3052 goto out; 3053 3054 err = -EINVAL; 3055 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 3056 goto out; 3057 3058 cp = try_then_request_module( 3059 find_compressor(ccp_option[0]), 3060 "ppp-compress-%d", ccp_option[0]); 3061 if (!cp) 3062 goto out; 3063 3064 err = -ENOBUFS; 3065 if (data->transmit) { 3066 state = cp->comp_alloc(ccp_option, data->length); 3067 if (state) { 3068 ppp_xmit_lock(ppp); 3069 ppp->xstate &= ~SC_COMP_RUN; 3070 ocomp = ppp->xcomp; 3071 ostate = ppp->xc_state; 3072 ppp->xcomp = cp; 3073 ppp->xc_state = state; 3074 ppp_xmit_unlock(ppp); 3075 if (ostate) { 3076 ocomp->comp_free(ostate); 3077 module_put(ocomp->owner); 3078 } 3079 err = 0; 3080 } else 3081 module_put(cp->owner); 3082 3083 } else { 3084 state = cp->decomp_alloc(ccp_option, data->length); 3085 if (state) { 3086 ppp_recv_lock(ppp); 3087 ppp->rstate &= ~SC_DECOMP_RUN; 3088 ocomp = ppp->rcomp; 3089 ostate = ppp->rc_state; 3090 ppp->rcomp = cp; 3091 ppp->rc_state = state; 3092 ppp_recv_unlock(ppp); 3093 if (ostate) { 3094 ocomp->decomp_free(ostate); 3095 module_put(ocomp->owner); 3096 } 3097 err = 0; 3098 } else 3099 module_put(cp->owner); 3100 } 3101 3102 out: 3103 return err; 3104 } 3105 3106 /* 3107 * Look at a CCP packet and update our state accordingly. 3108 * We assume the caller has the xmit or recv path locked. 3109 */ 3110 static void 3111 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 3112 { 3113 unsigned char *dp; 3114 int len; 3115 3116 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 3117 return; /* no header */ 3118 dp = skb->data + 2; 3119 3120 switch (CCP_CODE(dp)) { 3121 case CCP_CONFREQ: 3122 3123 /* A ConfReq starts negotiation of compression 3124 * in one direction of transmission, 3125 * and hence brings it down...but which way? 3126 * 3127 * Remember: 3128 * A ConfReq indicates what the sender would like to receive 3129 */ 3130 if(inbound) 3131 /* He is proposing what I should send */ 3132 ppp->xstate &= ~SC_COMP_RUN; 3133 else 3134 /* I am proposing to what he should send */ 3135 ppp->rstate &= ~SC_DECOMP_RUN; 3136 3137 break; 3138 3139 case CCP_TERMREQ: 3140 case CCP_TERMACK: 3141 /* 3142 * CCP is going down, both directions of transmission 3143 */ 3144 ppp->rstate &= ~SC_DECOMP_RUN; 3145 ppp->xstate &= ~SC_COMP_RUN; 3146 break; 3147 3148 case CCP_CONFACK: 3149 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 3150 break; 3151 len = CCP_LENGTH(dp); 3152 if (!pskb_may_pull(skb, len + 2)) 3153 return; /* too short */ 3154 dp += CCP_HDRLEN; 3155 len -= CCP_HDRLEN; 3156 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 3157 break; 3158 if (inbound) { 3159 /* we will start receiving compressed packets */ 3160 if (!ppp->rc_state) 3161 break; 3162 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 3163 ppp->file.index, 0, ppp->mru, ppp->debug)) { 3164 ppp->rstate |= SC_DECOMP_RUN; 3165 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 3166 } 3167 } else { 3168 /* we will soon start sending compressed packets */ 3169 if (!ppp->xc_state) 3170 break; 3171 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 3172 ppp->file.index, 0, ppp->debug)) 3173 ppp->xstate |= SC_COMP_RUN; 3174 } 3175 break; 3176 3177 case CCP_RESETACK: 3178 /* reset the [de]compressor */ 3179 if ((ppp->flags & SC_CCP_UP) == 0) 3180 break; 3181 if (inbound) { 3182 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 3183 ppp->rcomp->decomp_reset(ppp->rc_state); 3184 ppp->rstate &= ~SC_DC_ERROR; 3185 } 3186 } else { 3187 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 3188 ppp->xcomp->comp_reset(ppp->xc_state); 3189 } 3190 break; 3191 } 3192 } 3193 3194 /* Free up compression resources. */ 3195 static void 3196 ppp_ccp_closed(struct ppp *ppp) 3197 { 3198 void *xstate, *rstate; 3199 struct compressor *xcomp, *rcomp; 3200 3201 ppp_lock(ppp); 3202 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 3203 ppp->xstate = 0; 3204 xcomp = ppp->xcomp; 3205 xstate = ppp->xc_state; 3206 ppp->xc_state = NULL; 3207 ppp->rstate = 0; 3208 rcomp = ppp->rcomp; 3209 rstate = ppp->rc_state; 3210 ppp->rc_state = NULL; 3211 ppp_unlock(ppp); 3212 3213 if (xstate) { 3214 xcomp->comp_free(xstate); 3215 module_put(xcomp->owner); 3216 } 3217 if (rstate) { 3218 rcomp->decomp_free(rstate); 3219 module_put(rcomp->owner); 3220 } 3221 } 3222 3223 /* List of compressors. */ 3224 static LIST_HEAD(compressor_list); 3225 static DEFINE_SPINLOCK(compressor_list_lock); 3226 3227 struct compressor_entry { 3228 struct list_head list; 3229 struct compressor *comp; 3230 }; 3231 3232 static struct compressor_entry * 3233 find_comp_entry(int proto) 3234 { 3235 struct compressor_entry *ce; 3236 3237 list_for_each_entry(ce, &compressor_list, list) { 3238 if (ce->comp->compress_proto == proto) 3239 return ce; 3240 } 3241 return NULL; 3242 } 3243 3244 /* Register a compressor */ 3245 int 3246 ppp_register_compressor(struct compressor *cp) 3247 { 3248 struct compressor_entry *ce; 3249 int ret; 3250 spin_lock(&compressor_list_lock); 3251 ret = -EEXIST; 3252 if (find_comp_entry(cp->compress_proto)) 3253 goto out; 3254 ret = -ENOMEM; 3255 ce = kmalloc_obj(struct compressor_entry, GFP_ATOMIC); 3256 if (!ce) 3257 goto out; 3258 ret = 0; 3259 ce->comp = cp; 3260 list_add(&ce->list, &compressor_list); 3261 out: 3262 spin_unlock(&compressor_list_lock); 3263 return ret; 3264 } 3265 3266 /* Unregister a compressor */ 3267 void 3268 ppp_unregister_compressor(struct compressor *cp) 3269 { 3270 struct compressor_entry *ce; 3271 3272 spin_lock(&compressor_list_lock); 3273 ce = find_comp_entry(cp->compress_proto); 3274 if (ce && ce->comp == cp) { 3275 list_del(&ce->list); 3276 kfree(ce); 3277 } 3278 spin_unlock(&compressor_list_lock); 3279 } 3280 3281 /* Find a compressor. */ 3282 static struct compressor * 3283 find_compressor(int type) 3284 { 3285 struct compressor_entry *ce; 3286 struct compressor *cp = NULL; 3287 3288 spin_lock(&compressor_list_lock); 3289 ce = find_comp_entry(type); 3290 if (ce) { 3291 cp = ce->comp; 3292 if (!try_module_get(cp->owner)) 3293 cp = NULL; 3294 } 3295 spin_unlock(&compressor_list_lock); 3296 return cp; 3297 } 3298 3299 /* 3300 * Miscelleneous stuff. 3301 */ 3302 3303 static void 3304 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3305 { 3306 struct slcompress *vj = ppp->vj; 3307 int cpu; 3308 3309 memset(st, 0, sizeof(*st)); 3310 for_each_possible_cpu(cpu) { 3311 struct pcpu_sw_netstats *p = per_cpu_ptr(ppp->dev->tstats, cpu); 3312 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 3313 3314 rx_packets = u64_stats_read(&p->rx_packets); 3315 rx_bytes = u64_stats_read(&p->rx_bytes); 3316 tx_packets = u64_stats_read(&p->tx_packets); 3317 tx_bytes = u64_stats_read(&p->tx_bytes); 3318 3319 st->p.ppp_ipackets += rx_packets; 3320 st->p.ppp_ibytes += rx_bytes; 3321 st->p.ppp_opackets += tx_packets; 3322 st->p.ppp_obytes += tx_bytes; 3323 } 3324 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3325 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3326 if (!vj) 3327 return; 3328 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3329 st->vj.vjs_compressed = vj->sls_o_compressed; 3330 st->vj.vjs_searches = vj->sls_o_searches; 3331 st->vj.vjs_misses = vj->sls_o_misses; 3332 st->vj.vjs_errorin = vj->sls_i_error; 3333 st->vj.vjs_tossed = vj->sls_i_tossed; 3334 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3335 st->vj.vjs_compressedin = vj->sls_i_compressed; 3336 } 3337 3338 /* 3339 * Stuff for handling the lists of ppp units and channels 3340 * and for initialization. 3341 */ 3342 3343 /* 3344 * Create a new ppp interface unit. Fails if it can't allocate memory 3345 * or if there is already a unit with the requested number. 3346 * unit == -1 means allocate a new number. 3347 */ 3348 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3349 { 3350 struct ppp_config conf = { 3351 .file = file, 3352 .unit = *unit, 3353 .ifname_is_set = false, 3354 }; 3355 struct net_device *dev; 3356 struct ppp *ppp; 3357 int err; 3358 3359 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3360 if (!dev) { 3361 err = -ENOMEM; 3362 goto err; 3363 } 3364 dev_net_set(dev, net); 3365 dev->rtnl_link_ops = &ppp_link_ops; 3366 3367 rtnl_lock(); 3368 3369 err = ppp_dev_configure(net, dev, &conf); 3370 if (err < 0) 3371 goto err_dev; 3372 ppp = netdev_priv(dev); 3373 *unit = ppp->file.index; 3374 3375 rtnl_unlock(); 3376 3377 return 0; 3378 3379 err_dev: 3380 rtnl_unlock(); 3381 free_netdev(dev); 3382 err: 3383 return err; 3384 } 3385 3386 /* 3387 * Initialize a ppp_file structure. 3388 */ 3389 static void 3390 init_ppp_file(struct ppp_file *pf, int kind) 3391 { 3392 pf->kind = kind; 3393 skb_queue_head_init(&pf->xq); 3394 skb_queue_head_init(&pf->rq); 3395 refcount_set(&pf->refcnt, 1); 3396 init_waitqueue_head(&pf->rwait); 3397 } 3398 3399 /* 3400 * Drop a reference to a ppp unit and free its memory if the refcount reaches 3401 * zero. 3402 */ 3403 static void ppp_release_interface(struct ppp *ppp) 3404 { 3405 if (!refcount_dec_and_test(&ppp->file.refcnt)) 3406 return; 3407 3408 atomic_dec(&ppp_unit_count); 3409 3410 if (!ppp->file.dead || ppp->n_channels) { 3411 /* "can't happen" */ 3412 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3413 "but dead=%d n_channels=%d !\n", 3414 ppp, ppp->file.dead, ppp->n_channels); 3415 return; 3416 } 3417 3418 ppp_ccp_closed(ppp); 3419 if (ppp->vj) { 3420 slhc_free(ppp->vj); 3421 ppp->vj = NULL; 3422 } 3423 skb_queue_purge(&ppp->file.xq); 3424 skb_queue_purge(&ppp->file.rq); 3425 #ifdef CONFIG_PPP_MULTILINK 3426 skb_queue_purge(&ppp->mrq); 3427 #endif /* CONFIG_PPP_MULTILINK */ 3428 #ifdef CONFIG_PPP_FILTER 3429 if (ppp->pass_filter) { 3430 bpf_prog_destroy(ppp->pass_filter); 3431 ppp->pass_filter = NULL; 3432 } 3433 3434 if (ppp->active_filter) { 3435 bpf_prog_destroy(ppp->active_filter); 3436 ppp->active_filter = NULL; 3437 } 3438 #endif /* CONFIG_PPP_FILTER */ 3439 3440 free_percpu(ppp->xmit_recursion); 3441 3442 free_netdev(ppp->dev); 3443 } 3444 3445 /* 3446 * Locate an existing ppp unit. 3447 * The caller should have locked the all_ppp_mutex. 3448 */ 3449 static struct ppp * 3450 ppp_find_unit(struct ppp_net *pn, int unit) 3451 { 3452 return unit_find(&pn->units_idr, unit); 3453 } 3454 3455 /* 3456 * Locate an existing ppp channel. 3457 * The caller should have locked the all_channels_lock. 3458 * First we look in the new_channels list, then in the 3459 * all_channels list. If found in the new_channels list, 3460 * we move it to the all_channels list. This is for speed 3461 * when we have a lot of channels in use. 3462 */ 3463 static struct channel * 3464 ppp_find_channel(struct ppp_net *pn, int unit) 3465 { 3466 struct channel *pch; 3467 3468 list_for_each_entry(pch, &pn->new_channels, list) { 3469 if (pch->file.index == unit) { 3470 list_move(&pch->list, &pn->all_channels); 3471 return pch; 3472 } 3473 } 3474 3475 list_for_each_entry(pch, &pn->all_channels, list) { 3476 if (pch->file.index == unit) 3477 return pch; 3478 } 3479 3480 return NULL; 3481 } 3482 3483 /* 3484 * Connect a PPP channel to a PPP interface unit. 3485 */ 3486 static int 3487 ppp_connect_channel(struct channel *pch, int unit) 3488 { 3489 struct ppp *ppp; 3490 struct ppp_net *pn; 3491 int ret = -ENXIO; 3492 int hdrlen; 3493 3494 pn = ppp_pernet(pch->chan_net); 3495 3496 mutex_lock(&pn->all_ppp_mutex); 3497 ppp = ppp_find_unit(pn, unit); 3498 if (!ppp) 3499 goto out; 3500 spin_lock(&pch->upl); 3501 ret = -EINVAL; 3502 if (rcu_dereference_protected(pch->ppp, lockdep_is_held(&pch->upl)) || 3503 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) 3504 goto outl; 3505 3506 ppp_lock(ppp); 3507 spin_lock_bh(&pch->downl); 3508 if (!pch->chan) { 3509 /* Don't connect unregistered channels */ 3510 spin_unlock_bh(&pch->downl); 3511 ppp_unlock(ppp); 3512 ret = -ENOTCONN; 3513 goto outl; 3514 } 3515 if (pch->chan->direct_xmit) 3516 ppp->dev->priv_flags |= IFF_NO_QUEUE; 3517 else 3518 ppp->dev->priv_flags &= ~IFF_NO_QUEUE; 3519 spin_unlock_bh(&pch->downl); 3520 if (pch->file.hdrlen > ppp->file.hdrlen) 3521 ppp->file.hdrlen = pch->file.hdrlen; 3522 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3523 if (hdrlen > ppp->dev->hard_header_len) 3524 ppp->dev->hard_header_len = hdrlen; 3525 list_add_tail_rcu(&pch->clist, &ppp->channels); 3526 ++ppp->n_channels; 3527 rcu_assign_pointer(pch->ppp, ppp); 3528 refcount_inc(&ppp->file.refcnt); 3529 ppp_unlock(ppp); 3530 ret = 0; 3531 3532 outl: 3533 spin_unlock(&pch->upl); 3534 out: 3535 mutex_unlock(&pn->all_ppp_mutex); 3536 return ret; 3537 } 3538 3539 /* 3540 * Disconnect a channel from its ppp unit. 3541 */ 3542 static int 3543 ppp_disconnect_channel(struct channel *pch) 3544 { 3545 struct ppp *ppp; 3546 int err = -EINVAL; 3547 3548 spin_lock(&pch->upl); 3549 ppp = rcu_replace_pointer(pch->ppp, NULL, lockdep_is_held(&pch->upl)); 3550 spin_unlock(&pch->upl); 3551 if (ppp) { 3552 /* remove it from the ppp unit's list */ 3553 ppp_lock(ppp); 3554 list_del_rcu(&pch->clist); 3555 if (--ppp->n_channels == 0) 3556 wake_up_interruptible(&ppp->file.rwait); 3557 ppp_unlock(ppp); 3558 synchronize_net(); 3559 ppp_release_interface(ppp); 3560 err = 0; 3561 } 3562 return err; 3563 } 3564 3565 /* 3566 * Drop a reference to a ppp channel and free its memory if the refcount reaches 3567 * zero. 3568 */ 3569 static void ppp_release_channel(struct channel *pch) 3570 { 3571 if (!refcount_dec_and_test(&pch->file.refcnt)) 3572 return; 3573 3574 put_net_track(pch->chan_net, &pch->ns_tracker); 3575 pch->chan_net = NULL; 3576 3577 atomic_dec(&channel_count); 3578 3579 if (!pch->file.dead) { 3580 /* "can't happen" */ 3581 pr_err("ppp: destroying undead channel %p !\n", pch); 3582 return; 3583 } 3584 skb_queue_purge(&pch->file.xq); 3585 skb_queue_purge(&pch->file.rq); 3586 kfree(pch); 3587 } 3588 3589 static void __exit ppp_cleanup(void) 3590 { 3591 /* should never happen */ 3592 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3593 pr_err("PPP: removing module but units remain!\n"); 3594 rtnl_link_unregister(&ppp_link_ops); 3595 unregister_chrdev(PPP_MAJOR, "ppp"); 3596 device_destroy(&ppp_class, MKDEV(PPP_MAJOR, 0)); 3597 class_unregister(&ppp_class); 3598 unregister_pernet_device(&ppp_net_ops); 3599 } 3600 3601 /* 3602 * Units handling. Caller must protect concurrent access 3603 * by holding all_ppp_mutex 3604 */ 3605 3606 /* associate pointer with specified number */ 3607 static int unit_set(struct idr *p, void *ptr, int n) 3608 { 3609 int unit; 3610 3611 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3612 if (unit == -ENOSPC) 3613 unit = -EINVAL; 3614 return unit; 3615 } 3616 3617 /* get new free unit number and associate pointer with it */ 3618 static int unit_get(struct idr *p, void *ptr, int min) 3619 { 3620 return idr_alloc(p, ptr, min, 0, GFP_KERNEL); 3621 } 3622 3623 /* put unit number back to a pool */ 3624 static void unit_put(struct idr *p, int n) 3625 { 3626 idr_remove(p, n); 3627 } 3628 3629 /* get pointer associated with the number */ 3630 static void *unit_find(struct idr *p, int n) 3631 { 3632 return idr_find(p, n); 3633 } 3634 3635 /* Module/initialization stuff */ 3636 3637 module_init(ppp_init); 3638 module_exit(ppp_cleanup); 3639 3640 EXPORT_SYMBOL(ppp_register_net_channel); 3641 EXPORT_SYMBOL(ppp_register_channel); 3642 EXPORT_SYMBOL(ppp_unregister_channel); 3643 EXPORT_SYMBOL(ppp_channel_index); 3644 EXPORT_SYMBOL(ppp_unit_number); 3645 EXPORT_SYMBOL(ppp_dev_name); 3646 EXPORT_SYMBOL(ppp_input); 3647 EXPORT_SYMBOL(ppp_input_error); 3648 EXPORT_SYMBOL(ppp_output_wakeup); 3649 EXPORT_SYMBOL(ppp_register_compressor); 3650 EXPORT_SYMBOL(ppp_unregister_compressor); 3651 MODULE_DESCRIPTION("Generic PPP layer driver"); 3652 MODULE_LICENSE("GPL"); 3653 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3654 MODULE_ALIAS_RTNL_LINK("ppp"); 3655 MODULE_ALIAS("devname:ppp"); 3656