1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Generic PPP layer for Linux. 4 * 5 * Copyright 1999-2002 Paul Mackerras. 6 * 7 * The generic PPP layer handles the PPP network interfaces, the 8 * /dev/ppp device, packet and VJ compression, and multilink. 9 * It talks to PPP `channels' via the interface defined in 10 * include/linux/ppp_channel.h. Channels provide the basic means for 11 * sending and receiving PPP frames on some kind of communications 12 * channel. 13 * 14 * Part of the code in this driver was inspired by the old async-only 15 * PPP driver, written by Michael Callahan and Al Longyear, and 16 * subsequently hacked by Paul Mackerras. 17 * 18 * ==FILEVERSION 20041108== 19 */ 20 21 #include <linux/module.h> 22 #include <linux/kernel.h> 23 #include <linux/sched/signal.h> 24 #include <linux/kmod.h> 25 #include <linux/init.h> 26 #include <linux/list.h> 27 #include <linux/idr.h> 28 #include <linux/netdevice.h> 29 #include <linux/poll.h> 30 #include <linux/ppp_defs.h> 31 #include <linux/filter.h> 32 #include <linux/ppp-ioctl.h> 33 #include <linux/ppp_channel.h> 34 #include <linux/ppp-comp.h> 35 #include <linux/skbuff.h> 36 #include <linux/rtnetlink.h> 37 #include <linux/if_arp.h> 38 #include <linux/ip.h> 39 #include <linux/tcp.h> 40 #include <linux/spinlock.h> 41 #include <linux/rwsem.h> 42 #include <linux/stddef.h> 43 #include <linux/device.h> 44 #include <linux/mutex.h> 45 #include <linux/slab.h> 46 #include <linux/file.h> 47 #include <asm/unaligned.h> 48 #include <net/slhc_vj.h> 49 #include <linux/atomic.h> 50 #include <linux/refcount.h> 51 52 #include <linux/nsproxy.h> 53 #include <net/net_namespace.h> 54 #include <net/netns/generic.h> 55 56 #define PPP_VERSION "2.4.2" 57 58 /* 59 * Network protocols we support. 60 */ 61 #define NP_IP 0 /* Internet Protocol V4 */ 62 #define NP_IPV6 1 /* Internet Protocol V6 */ 63 #define NP_IPX 2 /* IPX protocol */ 64 #define NP_AT 3 /* Appletalk protocol */ 65 #define NP_MPLS_UC 4 /* MPLS unicast */ 66 #define NP_MPLS_MC 5 /* MPLS multicast */ 67 #define NUM_NP 6 /* Number of NPs. */ 68 69 #define MPHDRLEN 6 /* multilink protocol header length */ 70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 71 72 #define PPP_PROTO_LEN 2 73 #define PPP_LCP_HDRLEN 4 74 75 /* 76 * An instance of /dev/ppp can be associated with either a ppp 77 * interface unit or a ppp channel. In both cases, file->private_data 78 * points to one of these. 79 */ 80 struct ppp_file { 81 enum { 82 INTERFACE=1, CHANNEL 83 } kind; 84 struct sk_buff_head xq; /* pppd transmit queue */ 85 struct sk_buff_head rq; /* receive queue for pppd */ 86 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 87 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 88 int hdrlen; /* space to leave for headers */ 89 int index; /* interface unit / channel number */ 90 int dead; /* unit/channel has been shut down */ 91 }; 92 93 #define PF_TO_X(pf, X) container_of(pf, X, file) 94 95 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 96 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 97 98 /* 99 * Data structure to hold primary network stats for which 100 * we want to use 64 bit storage. Other network stats 101 * are stored in dev->stats of the ppp strucute. 102 */ 103 struct ppp_link_stats { 104 u64 rx_packets; 105 u64 tx_packets; 106 u64 rx_bytes; 107 u64 tx_bytes; 108 }; 109 110 /* 111 * Data structure describing one ppp unit. 112 * A ppp unit corresponds to a ppp network interface device 113 * and represents a multilink bundle. 114 * It can have 0 or more ppp channels connected to it. 115 */ 116 struct ppp { 117 struct ppp_file file; /* stuff for read/write/poll 0 */ 118 struct file *owner; /* file that owns this unit 48 */ 119 struct list_head channels; /* list of attached channels 4c */ 120 int n_channels; /* how many channels are attached 54 */ 121 spinlock_t rlock; /* lock for receive side 58 */ 122 spinlock_t wlock; /* lock for transmit side 5c */ 123 int __percpu *xmit_recursion; /* xmit recursion detect */ 124 int mru; /* max receive unit 60 */ 125 unsigned int flags; /* control bits 64 */ 126 unsigned int xstate; /* transmit state bits 68 */ 127 unsigned int rstate; /* receive state bits 6c */ 128 int debug; /* debug flags 70 */ 129 struct slcompress *vj; /* state for VJ header compression */ 130 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 131 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 132 struct compressor *xcomp; /* transmit packet compressor 8c */ 133 void *xc_state; /* its internal state 90 */ 134 struct compressor *rcomp; /* receive decompressor 94 */ 135 void *rc_state; /* its internal state 98 */ 136 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 137 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 138 struct net_device *dev; /* network interface device a4 */ 139 int closing; /* is device closing down? a8 */ 140 #ifdef CONFIG_PPP_MULTILINK 141 int nxchan; /* next channel to send something on */ 142 u32 nxseq; /* next sequence number to send */ 143 int mrru; /* MP: max reconst. receive unit */ 144 u32 nextseq; /* MP: seq no of next packet */ 145 u32 minseq; /* MP: min of most recent seqnos */ 146 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 147 #endif /* CONFIG_PPP_MULTILINK */ 148 #ifdef CONFIG_PPP_FILTER 149 struct bpf_prog *pass_filter; /* filter for packets to pass */ 150 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 151 #endif /* CONFIG_PPP_FILTER */ 152 struct net *ppp_net; /* the net we belong to */ 153 struct ppp_link_stats stats64; /* 64 bit network stats */ 154 }; 155 156 /* 157 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 158 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 159 * SC_MUST_COMP 160 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 161 * Bits in xstate: SC_COMP_RUN 162 */ 163 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 164 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 165 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 166 167 /* 168 * Private data structure for each channel. 169 * This includes the data structure used for multilink. 170 */ 171 struct channel { 172 struct ppp_file file; /* stuff for read/write/poll */ 173 struct list_head list; /* link in all/new_channels list */ 174 struct ppp_channel *chan; /* public channel data structure */ 175 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 176 spinlock_t downl; /* protects `chan', file.xq dequeue */ 177 struct ppp *ppp; /* ppp unit we're connected to */ 178 struct net *chan_net; /* the net channel belongs to */ 179 netns_tracker ns_tracker; 180 struct list_head clist; /* link in list of channels per unit */ 181 rwlock_t upl; /* protects `ppp' and 'bridge' */ 182 struct channel __rcu *bridge; /* "bridged" ppp channel */ 183 #ifdef CONFIG_PPP_MULTILINK 184 u8 avail; /* flag used in multilink stuff */ 185 u8 had_frag; /* >= 1 fragments have been sent */ 186 u32 lastseq; /* MP: last sequence # received */ 187 int speed; /* speed of the corresponding ppp channel*/ 188 #endif /* CONFIG_PPP_MULTILINK */ 189 }; 190 191 struct ppp_config { 192 struct file *file; 193 s32 unit; 194 bool ifname_is_set; 195 }; 196 197 /* 198 * SMP locking issues: 199 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 200 * list and the ppp.n_channels field, you need to take both locks 201 * before you modify them. 202 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 203 * channel.downl. 204 */ 205 206 static DEFINE_MUTEX(ppp_mutex); 207 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 208 static atomic_t channel_count = ATOMIC_INIT(0); 209 210 /* per-net private data for this module */ 211 static unsigned int ppp_net_id __read_mostly; 212 struct ppp_net { 213 /* units to ppp mapping */ 214 struct idr units_idr; 215 216 /* 217 * all_ppp_mutex protects the units_idr mapping. 218 * It also ensures that finding a ppp unit in the units_idr 219 * map and updating its file.refcnt field is atomic. 220 */ 221 struct mutex all_ppp_mutex; 222 223 /* channels */ 224 struct list_head all_channels; 225 struct list_head new_channels; 226 int last_channel_index; 227 228 /* 229 * all_channels_lock protects all_channels and 230 * last_channel_index, and the atomicity of find 231 * a channel and updating its file.refcnt field. 232 */ 233 spinlock_t all_channels_lock; 234 }; 235 236 /* Get the PPP protocol number from a skb */ 237 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 238 239 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 240 #define PPP_MAX_RQLEN 32 241 242 /* 243 * Maximum number of multilink fragments queued up. 244 * This has to be large enough to cope with the maximum latency of 245 * the slowest channel relative to the others. Strictly it should 246 * depend on the number of channels and their characteristics. 247 */ 248 #define PPP_MP_MAX_QLEN 128 249 250 /* Multilink header bits. */ 251 #define B 0x80 /* this fragment begins a packet */ 252 #define E 0x40 /* this fragment ends a packet */ 253 254 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 255 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 256 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 257 258 /* Prototypes. */ 259 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 260 struct file *file, unsigned int cmd, unsigned long arg); 261 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 262 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 263 static void ppp_push(struct ppp *ppp); 264 static void ppp_channel_push(struct channel *pch); 265 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 266 struct channel *pch); 267 static void ppp_receive_error(struct ppp *ppp); 268 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 269 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 270 struct sk_buff *skb); 271 #ifdef CONFIG_PPP_MULTILINK 272 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 273 struct channel *pch); 274 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 275 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 276 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 277 #endif /* CONFIG_PPP_MULTILINK */ 278 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data); 279 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 280 static void ppp_ccp_closed(struct ppp *ppp); 281 static struct compressor *find_compressor(int type); 282 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 283 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 284 static void init_ppp_file(struct ppp_file *pf, int kind); 285 static void ppp_destroy_interface(struct ppp *ppp); 286 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 287 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 288 static int ppp_connect_channel(struct channel *pch, int unit); 289 static int ppp_disconnect_channel(struct channel *pch); 290 static void ppp_destroy_channel(struct channel *pch); 291 static int unit_get(struct idr *p, void *ptr, int min); 292 static int unit_set(struct idr *p, void *ptr, int n); 293 static void unit_put(struct idr *p, int n); 294 static void *unit_find(struct idr *p, int n); 295 static void ppp_setup(struct net_device *dev); 296 297 static const struct net_device_ops ppp_netdev_ops; 298 299 static struct class *ppp_class; 300 301 /* per net-namespace data */ 302 static inline struct ppp_net *ppp_pernet(struct net *net) 303 { 304 return net_generic(net, ppp_net_id); 305 } 306 307 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 308 static inline int proto_to_npindex(int proto) 309 { 310 switch (proto) { 311 case PPP_IP: 312 return NP_IP; 313 case PPP_IPV6: 314 return NP_IPV6; 315 case PPP_IPX: 316 return NP_IPX; 317 case PPP_AT: 318 return NP_AT; 319 case PPP_MPLS_UC: 320 return NP_MPLS_UC; 321 case PPP_MPLS_MC: 322 return NP_MPLS_MC; 323 } 324 return -EINVAL; 325 } 326 327 /* Translates an NP index into a PPP protocol number */ 328 static const int npindex_to_proto[NUM_NP] = { 329 PPP_IP, 330 PPP_IPV6, 331 PPP_IPX, 332 PPP_AT, 333 PPP_MPLS_UC, 334 PPP_MPLS_MC, 335 }; 336 337 /* Translates an ethertype into an NP index */ 338 static inline int ethertype_to_npindex(int ethertype) 339 { 340 switch (ethertype) { 341 case ETH_P_IP: 342 return NP_IP; 343 case ETH_P_IPV6: 344 return NP_IPV6; 345 case ETH_P_IPX: 346 return NP_IPX; 347 case ETH_P_PPPTALK: 348 case ETH_P_ATALK: 349 return NP_AT; 350 case ETH_P_MPLS_UC: 351 return NP_MPLS_UC; 352 case ETH_P_MPLS_MC: 353 return NP_MPLS_MC; 354 } 355 return -1; 356 } 357 358 /* Translates an NP index into an ethertype */ 359 static const int npindex_to_ethertype[NUM_NP] = { 360 ETH_P_IP, 361 ETH_P_IPV6, 362 ETH_P_IPX, 363 ETH_P_PPPTALK, 364 ETH_P_MPLS_UC, 365 ETH_P_MPLS_MC, 366 }; 367 368 /* 369 * Locking shorthand. 370 */ 371 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 372 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 373 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 374 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 375 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 376 ppp_recv_lock(ppp); } while (0) 377 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 378 ppp_xmit_unlock(ppp); } while (0) 379 380 /* 381 * /dev/ppp device routines. 382 * The /dev/ppp device is used by pppd to control the ppp unit. 383 * It supports the read, write, ioctl and poll functions. 384 * Open instances of /dev/ppp can be in one of three states: 385 * unattached, attached to a ppp unit, or attached to a ppp channel. 386 */ 387 static int ppp_open(struct inode *inode, struct file *file) 388 { 389 /* 390 * This could (should?) be enforced by the permissions on /dev/ppp. 391 */ 392 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 393 return -EPERM; 394 return 0; 395 } 396 397 static int ppp_release(struct inode *unused, struct file *file) 398 { 399 struct ppp_file *pf = file->private_data; 400 struct ppp *ppp; 401 402 if (pf) { 403 file->private_data = NULL; 404 if (pf->kind == INTERFACE) { 405 ppp = PF_TO_PPP(pf); 406 rtnl_lock(); 407 if (file == ppp->owner) 408 unregister_netdevice(ppp->dev); 409 rtnl_unlock(); 410 } 411 if (refcount_dec_and_test(&pf->refcnt)) { 412 switch (pf->kind) { 413 case INTERFACE: 414 ppp_destroy_interface(PF_TO_PPP(pf)); 415 break; 416 case CHANNEL: 417 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 418 break; 419 } 420 } 421 } 422 return 0; 423 } 424 425 static ssize_t ppp_read(struct file *file, char __user *buf, 426 size_t count, loff_t *ppos) 427 { 428 struct ppp_file *pf = file->private_data; 429 DECLARE_WAITQUEUE(wait, current); 430 ssize_t ret; 431 struct sk_buff *skb = NULL; 432 struct iovec iov; 433 struct iov_iter to; 434 435 ret = count; 436 437 if (!pf) 438 return -ENXIO; 439 add_wait_queue(&pf->rwait, &wait); 440 for (;;) { 441 set_current_state(TASK_INTERRUPTIBLE); 442 skb = skb_dequeue(&pf->rq); 443 if (skb) 444 break; 445 ret = 0; 446 if (pf->dead) 447 break; 448 if (pf->kind == INTERFACE) { 449 /* 450 * Return 0 (EOF) on an interface that has no 451 * channels connected, unless it is looping 452 * network traffic (demand mode). 453 */ 454 struct ppp *ppp = PF_TO_PPP(pf); 455 456 ppp_recv_lock(ppp); 457 if (ppp->n_channels == 0 && 458 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 459 ppp_recv_unlock(ppp); 460 break; 461 } 462 ppp_recv_unlock(ppp); 463 } 464 ret = -EAGAIN; 465 if (file->f_flags & O_NONBLOCK) 466 break; 467 ret = -ERESTARTSYS; 468 if (signal_pending(current)) 469 break; 470 schedule(); 471 } 472 set_current_state(TASK_RUNNING); 473 remove_wait_queue(&pf->rwait, &wait); 474 475 if (!skb) 476 goto out; 477 478 ret = -EOVERFLOW; 479 if (skb->len > count) 480 goto outf; 481 ret = -EFAULT; 482 iov.iov_base = buf; 483 iov.iov_len = count; 484 iov_iter_init(&to, ITER_DEST, &iov, 1, count); 485 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 486 goto outf; 487 ret = skb->len; 488 489 outf: 490 kfree_skb(skb); 491 out: 492 return ret; 493 } 494 495 static bool ppp_check_packet(struct sk_buff *skb, size_t count) 496 { 497 /* LCP packets must include LCP header which 4 bytes long: 498 * 1-byte code, 1-byte identifier, and 2-byte length. 499 */ 500 return get_unaligned_be16(skb->data) != PPP_LCP || 501 count >= PPP_PROTO_LEN + PPP_LCP_HDRLEN; 502 } 503 504 static ssize_t ppp_write(struct file *file, const char __user *buf, 505 size_t count, loff_t *ppos) 506 { 507 struct ppp_file *pf = file->private_data; 508 struct sk_buff *skb; 509 ssize_t ret; 510 511 if (!pf) 512 return -ENXIO; 513 /* All PPP packets should start with the 2-byte protocol */ 514 if (count < PPP_PROTO_LEN) 515 return -EINVAL; 516 ret = -ENOMEM; 517 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 518 if (!skb) 519 goto out; 520 skb_reserve(skb, pf->hdrlen); 521 ret = -EFAULT; 522 if (copy_from_user(skb_put(skb, count), buf, count)) { 523 kfree_skb(skb); 524 goto out; 525 } 526 ret = -EINVAL; 527 if (unlikely(!ppp_check_packet(skb, count))) { 528 kfree_skb(skb); 529 goto out; 530 } 531 532 switch (pf->kind) { 533 case INTERFACE: 534 ppp_xmit_process(PF_TO_PPP(pf), skb); 535 break; 536 case CHANNEL: 537 skb_queue_tail(&pf->xq, skb); 538 ppp_channel_push(PF_TO_CHANNEL(pf)); 539 break; 540 } 541 542 ret = count; 543 544 out: 545 return ret; 546 } 547 548 /* No kernel lock - fine */ 549 static __poll_t ppp_poll(struct file *file, poll_table *wait) 550 { 551 struct ppp_file *pf = file->private_data; 552 __poll_t mask; 553 554 if (!pf) 555 return 0; 556 poll_wait(file, &pf->rwait, wait); 557 mask = EPOLLOUT | EPOLLWRNORM; 558 if (skb_peek(&pf->rq)) 559 mask |= EPOLLIN | EPOLLRDNORM; 560 if (pf->dead) 561 mask |= EPOLLHUP; 562 else if (pf->kind == INTERFACE) { 563 /* see comment in ppp_read */ 564 struct ppp *ppp = PF_TO_PPP(pf); 565 566 ppp_recv_lock(ppp); 567 if (ppp->n_channels == 0 && 568 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 569 mask |= EPOLLIN | EPOLLRDNORM; 570 ppp_recv_unlock(ppp); 571 } 572 573 return mask; 574 } 575 576 #ifdef CONFIG_PPP_FILTER 577 static struct bpf_prog *get_filter(struct sock_fprog *uprog) 578 { 579 struct sock_fprog_kern fprog; 580 struct bpf_prog *res = NULL; 581 int err; 582 583 if (!uprog->len) 584 return NULL; 585 586 /* uprog->len is unsigned short, so no overflow here */ 587 fprog.len = uprog->len; 588 fprog.filter = memdup_user(uprog->filter, 589 uprog->len * sizeof(struct sock_filter)); 590 if (IS_ERR(fprog.filter)) 591 return ERR_CAST(fprog.filter); 592 593 err = bpf_prog_create(&res, &fprog); 594 kfree(fprog.filter); 595 596 return err ? ERR_PTR(err) : res; 597 } 598 599 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p) 600 { 601 struct sock_fprog uprog; 602 603 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog))) 604 return ERR_PTR(-EFAULT); 605 return get_filter(&uprog); 606 } 607 608 #ifdef CONFIG_COMPAT 609 struct sock_fprog32 { 610 unsigned short len; 611 compat_caddr_t filter; 612 }; 613 614 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32) 615 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32) 616 617 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) 618 { 619 struct sock_fprog32 uprog32; 620 struct sock_fprog uprog; 621 622 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32))) 623 return ERR_PTR(-EFAULT); 624 uprog.len = uprog32.len; 625 uprog.filter = compat_ptr(uprog32.filter); 626 return get_filter(&uprog); 627 } 628 #endif 629 #endif 630 631 /* Bridge one PPP channel to another. 632 * When two channels are bridged, ppp_input on one channel is redirected to 633 * the other's ops->start_xmit handler. 634 * In order to safely bridge channels we must reject channels which are already 635 * part of a bridge instance, or which form part of an existing unit. 636 * Once successfully bridged, each channel holds a reference on the other 637 * to prevent it being freed while the bridge is extant. 638 */ 639 static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) 640 { 641 write_lock_bh(&pch->upl); 642 if (pch->ppp || 643 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) { 644 write_unlock_bh(&pch->upl); 645 return -EALREADY; 646 } 647 refcount_inc(&pchb->file.refcnt); 648 rcu_assign_pointer(pch->bridge, pchb); 649 write_unlock_bh(&pch->upl); 650 651 write_lock_bh(&pchb->upl); 652 if (pchb->ppp || 653 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) { 654 write_unlock_bh(&pchb->upl); 655 goto err_unset; 656 } 657 refcount_inc(&pch->file.refcnt); 658 rcu_assign_pointer(pchb->bridge, pch); 659 write_unlock_bh(&pchb->upl); 660 661 return 0; 662 663 err_unset: 664 write_lock_bh(&pch->upl); 665 /* Re-read pch->bridge with upl held in case it was modified concurrently */ 666 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 667 RCU_INIT_POINTER(pch->bridge, NULL); 668 write_unlock_bh(&pch->upl); 669 synchronize_rcu(); 670 671 if (pchb) 672 if (refcount_dec_and_test(&pchb->file.refcnt)) 673 ppp_destroy_channel(pchb); 674 675 return -EALREADY; 676 } 677 678 static int ppp_unbridge_channels(struct channel *pch) 679 { 680 struct channel *pchb, *pchbb; 681 682 write_lock_bh(&pch->upl); 683 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 684 if (!pchb) { 685 write_unlock_bh(&pch->upl); 686 return -EINVAL; 687 } 688 RCU_INIT_POINTER(pch->bridge, NULL); 689 write_unlock_bh(&pch->upl); 690 691 /* Only modify pchb if phcb->bridge points back to pch. 692 * If not, it implies that there has been a race unbridging (and possibly 693 * even rebridging) pchb. We should leave pchb alone to avoid either a 694 * refcount underflow, or breaking another established bridge instance. 695 */ 696 write_lock_bh(&pchb->upl); 697 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl)); 698 if (pchbb == pch) 699 RCU_INIT_POINTER(pchb->bridge, NULL); 700 write_unlock_bh(&pchb->upl); 701 702 synchronize_rcu(); 703 704 if (pchbb == pch) 705 if (refcount_dec_and_test(&pch->file.refcnt)) 706 ppp_destroy_channel(pch); 707 708 if (refcount_dec_and_test(&pchb->file.refcnt)) 709 ppp_destroy_channel(pchb); 710 711 return 0; 712 } 713 714 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 715 { 716 struct ppp_file *pf; 717 struct ppp *ppp; 718 int err = -EFAULT, val, val2, i; 719 struct ppp_idle32 idle32; 720 struct ppp_idle64 idle64; 721 struct npioctl npi; 722 int unit, cflags; 723 struct slcompress *vj; 724 void __user *argp = (void __user *)arg; 725 int __user *p = argp; 726 727 mutex_lock(&ppp_mutex); 728 729 pf = file->private_data; 730 if (!pf) { 731 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 732 pf, file, cmd, arg); 733 goto out; 734 } 735 736 if (cmd == PPPIOCDETACH) { 737 /* 738 * PPPIOCDETACH is no longer supported as it was heavily broken, 739 * and is only known to have been used by pppd older than 740 * ppp-2.4.2 (released November 2003). 741 */ 742 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 743 current->comm, current->pid); 744 err = -EINVAL; 745 goto out; 746 } 747 748 if (pf->kind == CHANNEL) { 749 struct channel *pch, *pchb; 750 struct ppp_channel *chan; 751 struct ppp_net *pn; 752 753 pch = PF_TO_CHANNEL(pf); 754 755 switch (cmd) { 756 case PPPIOCCONNECT: 757 if (get_user(unit, p)) 758 break; 759 err = ppp_connect_channel(pch, unit); 760 break; 761 762 case PPPIOCDISCONN: 763 err = ppp_disconnect_channel(pch); 764 break; 765 766 case PPPIOCBRIDGECHAN: 767 if (get_user(unit, p)) 768 break; 769 err = -ENXIO; 770 pn = ppp_pernet(current->nsproxy->net_ns); 771 spin_lock_bh(&pn->all_channels_lock); 772 pchb = ppp_find_channel(pn, unit); 773 /* Hold a reference to prevent pchb being freed while 774 * we establish the bridge. 775 */ 776 if (pchb) 777 refcount_inc(&pchb->file.refcnt); 778 spin_unlock_bh(&pn->all_channels_lock); 779 if (!pchb) 780 break; 781 err = ppp_bridge_channels(pch, pchb); 782 /* Drop earlier refcount now bridge establishment is complete */ 783 if (refcount_dec_and_test(&pchb->file.refcnt)) 784 ppp_destroy_channel(pchb); 785 break; 786 787 case PPPIOCUNBRIDGECHAN: 788 err = ppp_unbridge_channels(pch); 789 break; 790 791 default: 792 down_read(&pch->chan_sem); 793 chan = pch->chan; 794 err = -ENOTTY; 795 if (chan && chan->ops->ioctl) 796 err = chan->ops->ioctl(chan, cmd, arg); 797 up_read(&pch->chan_sem); 798 } 799 goto out; 800 } 801 802 if (pf->kind != INTERFACE) { 803 /* can't happen */ 804 pr_err("PPP: not interface or channel??\n"); 805 err = -EINVAL; 806 goto out; 807 } 808 809 ppp = PF_TO_PPP(pf); 810 switch (cmd) { 811 case PPPIOCSMRU: 812 if (get_user(val, p)) 813 break; 814 ppp->mru = val; 815 err = 0; 816 break; 817 818 case PPPIOCSFLAGS: 819 if (get_user(val, p)) 820 break; 821 ppp_lock(ppp); 822 cflags = ppp->flags & ~val; 823 #ifdef CONFIG_PPP_MULTILINK 824 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 825 ppp->nextseq = 0; 826 #endif 827 ppp->flags = val & SC_FLAG_BITS; 828 ppp_unlock(ppp); 829 if (cflags & SC_CCP_OPEN) 830 ppp_ccp_closed(ppp); 831 err = 0; 832 break; 833 834 case PPPIOCGFLAGS: 835 val = ppp->flags | ppp->xstate | ppp->rstate; 836 if (put_user(val, p)) 837 break; 838 err = 0; 839 break; 840 841 case PPPIOCSCOMPRESS: 842 { 843 struct ppp_option_data data; 844 if (copy_from_user(&data, argp, sizeof(data))) 845 err = -EFAULT; 846 else 847 err = ppp_set_compress(ppp, &data); 848 break; 849 } 850 case PPPIOCGUNIT: 851 if (put_user(ppp->file.index, p)) 852 break; 853 err = 0; 854 break; 855 856 case PPPIOCSDEBUG: 857 if (get_user(val, p)) 858 break; 859 ppp->debug = val; 860 err = 0; 861 break; 862 863 case PPPIOCGDEBUG: 864 if (put_user(ppp->debug, p)) 865 break; 866 err = 0; 867 break; 868 869 case PPPIOCGIDLE32: 870 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 871 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; 872 if (copy_to_user(argp, &idle32, sizeof(idle32))) 873 break; 874 err = 0; 875 break; 876 877 case PPPIOCGIDLE64: 878 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 879 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; 880 if (copy_to_user(argp, &idle64, sizeof(idle64))) 881 break; 882 err = 0; 883 break; 884 885 case PPPIOCSMAXCID: 886 if (get_user(val, p)) 887 break; 888 val2 = 15; 889 if ((val >> 16) != 0) { 890 val2 = val >> 16; 891 val &= 0xffff; 892 } 893 vj = slhc_init(val2+1, val+1); 894 if (IS_ERR(vj)) { 895 err = PTR_ERR(vj); 896 break; 897 } 898 ppp_lock(ppp); 899 if (ppp->vj) 900 slhc_free(ppp->vj); 901 ppp->vj = vj; 902 ppp_unlock(ppp); 903 err = 0; 904 break; 905 906 case PPPIOCGNPMODE: 907 case PPPIOCSNPMODE: 908 if (copy_from_user(&npi, argp, sizeof(npi))) 909 break; 910 err = proto_to_npindex(npi.protocol); 911 if (err < 0) 912 break; 913 i = err; 914 if (cmd == PPPIOCGNPMODE) { 915 err = -EFAULT; 916 npi.mode = ppp->npmode[i]; 917 if (copy_to_user(argp, &npi, sizeof(npi))) 918 break; 919 } else { 920 ppp->npmode[i] = npi.mode; 921 /* we may be able to transmit more packets now (??) */ 922 netif_wake_queue(ppp->dev); 923 } 924 err = 0; 925 break; 926 927 #ifdef CONFIG_PPP_FILTER 928 case PPPIOCSPASS: 929 case PPPIOCSACTIVE: 930 { 931 struct bpf_prog *filter = ppp_get_filter(argp); 932 struct bpf_prog **which; 933 934 if (IS_ERR(filter)) { 935 err = PTR_ERR(filter); 936 break; 937 } 938 if (cmd == PPPIOCSPASS) 939 which = &ppp->pass_filter; 940 else 941 which = &ppp->active_filter; 942 ppp_lock(ppp); 943 if (*which) 944 bpf_prog_destroy(*which); 945 *which = filter; 946 ppp_unlock(ppp); 947 err = 0; 948 break; 949 } 950 #endif /* CONFIG_PPP_FILTER */ 951 952 #ifdef CONFIG_PPP_MULTILINK 953 case PPPIOCSMRRU: 954 if (get_user(val, p)) 955 break; 956 ppp_recv_lock(ppp); 957 ppp->mrru = val; 958 ppp_recv_unlock(ppp); 959 err = 0; 960 break; 961 #endif /* CONFIG_PPP_MULTILINK */ 962 963 default: 964 err = -ENOTTY; 965 } 966 967 out: 968 mutex_unlock(&ppp_mutex); 969 970 return err; 971 } 972 973 #ifdef CONFIG_COMPAT 974 struct ppp_option_data32 { 975 compat_uptr_t ptr; 976 u32 length; 977 compat_int_t transmit; 978 }; 979 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) 980 981 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 982 { 983 struct ppp_file *pf; 984 int err = -ENOIOCTLCMD; 985 void __user *argp = (void __user *)arg; 986 987 mutex_lock(&ppp_mutex); 988 989 pf = file->private_data; 990 if (pf && pf->kind == INTERFACE) { 991 struct ppp *ppp = PF_TO_PPP(pf); 992 switch (cmd) { 993 #ifdef CONFIG_PPP_FILTER 994 case PPPIOCSPASS32: 995 case PPPIOCSACTIVE32: 996 { 997 struct bpf_prog *filter = compat_ppp_get_filter(argp); 998 struct bpf_prog **which; 999 1000 if (IS_ERR(filter)) { 1001 err = PTR_ERR(filter); 1002 break; 1003 } 1004 if (cmd == PPPIOCSPASS32) 1005 which = &ppp->pass_filter; 1006 else 1007 which = &ppp->active_filter; 1008 ppp_lock(ppp); 1009 if (*which) 1010 bpf_prog_destroy(*which); 1011 *which = filter; 1012 ppp_unlock(ppp); 1013 err = 0; 1014 break; 1015 } 1016 #endif /* CONFIG_PPP_FILTER */ 1017 case PPPIOCSCOMPRESS32: 1018 { 1019 struct ppp_option_data32 data32; 1020 if (copy_from_user(&data32, argp, sizeof(data32))) { 1021 err = -EFAULT; 1022 } else { 1023 struct ppp_option_data data = { 1024 .ptr = compat_ptr(data32.ptr), 1025 .length = data32.length, 1026 .transmit = data32.transmit 1027 }; 1028 err = ppp_set_compress(ppp, &data); 1029 } 1030 break; 1031 } 1032 } 1033 } 1034 mutex_unlock(&ppp_mutex); 1035 1036 /* all other commands have compatible arguments */ 1037 if (err == -ENOIOCTLCMD) 1038 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1039 1040 return err; 1041 } 1042 #endif 1043 1044 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 1045 struct file *file, unsigned int cmd, unsigned long arg) 1046 { 1047 int unit, err = -EFAULT; 1048 struct ppp *ppp; 1049 struct channel *chan; 1050 struct ppp_net *pn; 1051 int __user *p = (int __user *)arg; 1052 1053 switch (cmd) { 1054 case PPPIOCNEWUNIT: 1055 /* Create a new ppp unit */ 1056 if (get_user(unit, p)) 1057 break; 1058 err = ppp_create_interface(net, file, &unit); 1059 if (err < 0) 1060 break; 1061 1062 err = -EFAULT; 1063 if (put_user(unit, p)) 1064 break; 1065 err = 0; 1066 break; 1067 1068 case PPPIOCATTACH: 1069 /* Attach to an existing ppp unit */ 1070 if (get_user(unit, p)) 1071 break; 1072 err = -ENXIO; 1073 pn = ppp_pernet(net); 1074 mutex_lock(&pn->all_ppp_mutex); 1075 ppp = ppp_find_unit(pn, unit); 1076 if (ppp) { 1077 refcount_inc(&ppp->file.refcnt); 1078 file->private_data = &ppp->file; 1079 err = 0; 1080 } 1081 mutex_unlock(&pn->all_ppp_mutex); 1082 break; 1083 1084 case PPPIOCATTCHAN: 1085 if (get_user(unit, p)) 1086 break; 1087 err = -ENXIO; 1088 pn = ppp_pernet(net); 1089 spin_lock_bh(&pn->all_channels_lock); 1090 chan = ppp_find_channel(pn, unit); 1091 if (chan) { 1092 refcount_inc(&chan->file.refcnt); 1093 file->private_data = &chan->file; 1094 err = 0; 1095 } 1096 spin_unlock_bh(&pn->all_channels_lock); 1097 break; 1098 1099 default: 1100 err = -ENOTTY; 1101 } 1102 1103 return err; 1104 } 1105 1106 static const struct file_operations ppp_device_fops = { 1107 .owner = THIS_MODULE, 1108 .read = ppp_read, 1109 .write = ppp_write, 1110 .poll = ppp_poll, 1111 .unlocked_ioctl = ppp_ioctl, 1112 #ifdef CONFIG_COMPAT 1113 .compat_ioctl = ppp_compat_ioctl, 1114 #endif 1115 .open = ppp_open, 1116 .release = ppp_release, 1117 .llseek = noop_llseek, 1118 }; 1119 1120 static __net_init int ppp_init_net(struct net *net) 1121 { 1122 struct ppp_net *pn = net_generic(net, ppp_net_id); 1123 1124 idr_init(&pn->units_idr); 1125 mutex_init(&pn->all_ppp_mutex); 1126 1127 INIT_LIST_HEAD(&pn->all_channels); 1128 INIT_LIST_HEAD(&pn->new_channels); 1129 1130 spin_lock_init(&pn->all_channels_lock); 1131 1132 return 0; 1133 } 1134 1135 static __net_exit void ppp_exit_net(struct net *net) 1136 { 1137 struct ppp_net *pn = net_generic(net, ppp_net_id); 1138 struct net_device *dev; 1139 struct net_device *aux; 1140 struct ppp *ppp; 1141 LIST_HEAD(list); 1142 int id; 1143 1144 rtnl_lock(); 1145 for_each_netdev_safe(net, dev, aux) { 1146 if (dev->netdev_ops == &ppp_netdev_ops) 1147 unregister_netdevice_queue(dev, &list); 1148 } 1149 1150 idr_for_each_entry(&pn->units_idr, ppp, id) 1151 /* Skip devices already unregistered by previous loop */ 1152 if (!net_eq(dev_net(ppp->dev), net)) 1153 unregister_netdevice_queue(ppp->dev, &list); 1154 1155 unregister_netdevice_many(&list); 1156 rtnl_unlock(); 1157 1158 mutex_destroy(&pn->all_ppp_mutex); 1159 idr_destroy(&pn->units_idr); 1160 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 1161 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 1162 } 1163 1164 static struct pernet_operations ppp_net_ops = { 1165 .init = ppp_init_net, 1166 .exit = ppp_exit_net, 1167 .id = &ppp_net_id, 1168 .size = sizeof(struct ppp_net), 1169 }; 1170 1171 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 1172 { 1173 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1174 int ret; 1175 1176 mutex_lock(&pn->all_ppp_mutex); 1177 1178 if (unit < 0) { 1179 ret = unit_get(&pn->units_idr, ppp, 0); 1180 if (ret < 0) 1181 goto err; 1182 if (!ifname_is_set) { 1183 while (1) { 1184 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret); 1185 if (!netdev_name_in_use(ppp->ppp_net, ppp->dev->name)) 1186 break; 1187 unit_put(&pn->units_idr, ret); 1188 ret = unit_get(&pn->units_idr, ppp, ret + 1); 1189 if (ret < 0) 1190 goto err; 1191 } 1192 } 1193 } else { 1194 /* Caller asked for a specific unit number. Fail with -EEXIST 1195 * if unavailable. For backward compatibility, return -EEXIST 1196 * too if idr allocation fails; this makes pppd retry without 1197 * requesting a specific unit number. 1198 */ 1199 if (unit_find(&pn->units_idr, unit)) { 1200 ret = -EEXIST; 1201 goto err; 1202 } 1203 ret = unit_set(&pn->units_idr, ppp, unit); 1204 if (ret < 0) { 1205 /* Rewrite error for backward compatibility */ 1206 ret = -EEXIST; 1207 goto err; 1208 } 1209 } 1210 ppp->file.index = ret; 1211 1212 if (!ifname_is_set) 1213 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1214 1215 mutex_unlock(&pn->all_ppp_mutex); 1216 1217 ret = register_netdevice(ppp->dev); 1218 if (ret < 0) 1219 goto err_unit; 1220 1221 atomic_inc(&ppp_unit_count); 1222 1223 return 0; 1224 1225 err_unit: 1226 mutex_lock(&pn->all_ppp_mutex); 1227 unit_put(&pn->units_idr, ppp->file.index); 1228 err: 1229 mutex_unlock(&pn->all_ppp_mutex); 1230 1231 return ret; 1232 } 1233 1234 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1235 const struct ppp_config *conf) 1236 { 1237 struct ppp *ppp = netdev_priv(dev); 1238 int indx; 1239 int err; 1240 int cpu; 1241 1242 ppp->dev = dev; 1243 ppp->ppp_net = src_net; 1244 ppp->mru = PPP_MRU; 1245 ppp->owner = conf->file; 1246 1247 init_ppp_file(&ppp->file, INTERFACE); 1248 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1249 1250 for (indx = 0; indx < NUM_NP; ++indx) 1251 ppp->npmode[indx] = NPMODE_PASS; 1252 INIT_LIST_HEAD(&ppp->channels); 1253 spin_lock_init(&ppp->rlock); 1254 spin_lock_init(&ppp->wlock); 1255 1256 ppp->xmit_recursion = alloc_percpu(int); 1257 if (!ppp->xmit_recursion) { 1258 err = -ENOMEM; 1259 goto err1; 1260 } 1261 for_each_possible_cpu(cpu) 1262 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1263 1264 #ifdef CONFIG_PPP_MULTILINK 1265 ppp->minseq = -1; 1266 skb_queue_head_init(&ppp->mrq); 1267 #endif /* CONFIG_PPP_MULTILINK */ 1268 #ifdef CONFIG_PPP_FILTER 1269 ppp->pass_filter = NULL; 1270 ppp->active_filter = NULL; 1271 #endif /* CONFIG_PPP_FILTER */ 1272 1273 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1274 if (err < 0) 1275 goto err2; 1276 1277 conf->file->private_data = &ppp->file; 1278 1279 return 0; 1280 err2: 1281 free_percpu(ppp->xmit_recursion); 1282 err1: 1283 return err; 1284 } 1285 1286 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1287 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1288 }; 1289 1290 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1291 struct netlink_ext_ack *extack) 1292 { 1293 if (!data) 1294 return -EINVAL; 1295 1296 if (!data[IFLA_PPP_DEV_FD]) 1297 return -EINVAL; 1298 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1299 return -EBADF; 1300 1301 return 0; 1302 } 1303 1304 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1305 struct nlattr *tb[], struct nlattr *data[], 1306 struct netlink_ext_ack *extack) 1307 { 1308 struct ppp_config conf = { 1309 .unit = -1, 1310 .ifname_is_set = true, 1311 }; 1312 struct file *file; 1313 int err; 1314 1315 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1316 if (!file) 1317 return -EBADF; 1318 1319 /* rtnl_lock is already held here, but ppp_create_interface() locks 1320 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1321 * possible deadlock due to lock order inversion, at the cost of 1322 * pushing the problem back to userspace. 1323 */ 1324 if (!mutex_trylock(&ppp_mutex)) { 1325 err = -EBUSY; 1326 goto out; 1327 } 1328 1329 if (file->f_op != &ppp_device_fops || file->private_data) { 1330 err = -EBADF; 1331 goto out_unlock; 1332 } 1333 1334 conf.file = file; 1335 1336 /* Don't use device name generated by the rtnetlink layer when ifname 1337 * isn't specified. Let ppp_dev_configure() set the device name using 1338 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1339 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1340 */ 1341 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME])) 1342 conf.ifname_is_set = false; 1343 1344 err = ppp_dev_configure(src_net, dev, &conf); 1345 1346 out_unlock: 1347 mutex_unlock(&ppp_mutex); 1348 out: 1349 fput(file); 1350 1351 return err; 1352 } 1353 1354 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1355 { 1356 unregister_netdevice_queue(dev, head); 1357 } 1358 1359 static size_t ppp_nl_get_size(const struct net_device *dev) 1360 { 1361 return 0; 1362 } 1363 1364 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1365 { 1366 return 0; 1367 } 1368 1369 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1370 { 1371 struct ppp *ppp = netdev_priv(dev); 1372 1373 return ppp->ppp_net; 1374 } 1375 1376 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1377 .kind = "ppp", 1378 .maxtype = IFLA_PPP_MAX, 1379 .policy = ppp_nl_policy, 1380 .priv_size = sizeof(struct ppp), 1381 .setup = ppp_setup, 1382 .validate = ppp_nl_validate, 1383 .newlink = ppp_nl_newlink, 1384 .dellink = ppp_nl_dellink, 1385 .get_size = ppp_nl_get_size, 1386 .fill_info = ppp_nl_fill_info, 1387 .get_link_net = ppp_nl_get_link_net, 1388 }; 1389 1390 #define PPP_MAJOR 108 1391 1392 /* Called at boot time if ppp is compiled into the kernel, 1393 or at module load time (from init_module) if compiled as a module. */ 1394 static int __init ppp_init(void) 1395 { 1396 int err; 1397 1398 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1399 1400 err = register_pernet_device(&ppp_net_ops); 1401 if (err) { 1402 pr_err("failed to register PPP pernet device (%d)\n", err); 1403 goto out; 1404 } 1405 1406 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1407 if (err) { 1408 pr_err("failed to register PPP device (%d)\n", err); 1409 goto out_net; 1410 } 1411 1412 ppp_class = class_create("ppp"); 1413 if (IS_ERR(ppp_class)) { 1414 err = PTR_ERR(ppp_class); 1415 goto out_chrdev; 1416 } 1417 1418 err = rtnl_link_register(&ppp_link_ops); 1419 if (err) { 1420 pr_err("failed to register rtnetlink PPP handler\n"); 1421 goto out_class; 1422 } 1423 1424 /* not a big deal if we fail here :-) */ 1425 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1426 1427 return 0; 1428 1429 out_class: 1430 class_destroy(ppp_class); 1431 out_chrdev: 1432 unregister_chrdev(PPP_MAJOR, "ppp"); 1433 out_net: 1434 unregister_pernet_device(&ppp_net_ops); 1435 out: 1436 return err; 1437 } 1438 1439 /* 1440 * Network interface unit routines. 1441 */ 1442 static netdev_tx_t 1443 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1444 { 1445 struct ppp *ppp = netdev_priv(dev); 1446 int npi, proto; 1447 unsigned char *pp; 1448 1449 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1450 if (npi < 0) 1451 goto outf; 1452 1453 /* Drop, accept or reject the packet */ 1454 switch (ppp->npmode[npi]) { 1455 case NPMODE_PASS: 1456 break; 1457 case NPMODE_QUEUE: 1458 /* it would be nice to have a way to tell the network 1459 system to queue this one up for later. */ 1460 goto outf; 1461 case NPMODE_DROP: 1462 case NPMODE_ERROR: 1463 goto outf; 1464 } 1465 1466 /* Put the 2-byte PPP protocol number on the front, 1467 making sure there is room for the address and control fields. */ 1468 if (skb_cow_head(skb, PPP_HDRLEN)) 1469 goto outf; 1470 1471 pp = skb_push(skb, 2); 1472 proto = npindex_to_proto[npi]; 1473 put_unaligned_be16(proto, pp); 1474 1475 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1476 ppp_xmit_process(ppp, skb); 1477 1478 return NETDEV_TX_OK; 1479 1480 outf: 1481 kfree_skb(skb); 1482 ++dev->stats.tx_dropped; 1483 return NETDEV_TX_OK; 1484 } 1485 1486 static int 1487 ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 1488 void __user *addr, int cmd) 1489 { 1490 struct ppp *ppp = netdev_priv(dev); 1491 int err = -EFAULT; 1492 struct ppp_stats stats; 1493 struct ppp_comp_stats cstats; 1494 char *vers; 1495 1496 switch (cmd) { 1497 case SIOCGPPPSTATS: 1498 ppp_get_stats(ppp, &stats); 1499 if (copy_to_user(addr, &stats, sizeof(stats))) 1500 break; 1501 err = 0; 1502 break; 1503 1504 case SIOCGPPPCSTATS: 1505 memset(&cstats, 0, sizeof(cstats)); 1506 if (ppp->xc_state) 1507 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1508 if (ppp->rc_state) 1509 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1510 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1511 break; 1512 err = 0; 1513 break; 1514 1515 case SIOCGPPPVER: 1516 vers = PPP_VERSION; 1517 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1518 break; 1519 err = 0; 1520 break; 1521 1522 default: 1523 err = -EINVAL; 1524 } 1525 1526 return err; 1527 } 1528 1529 static void 1530 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1531 { 1532 struct ppp *ppp = netdev_priv(dev); 1533 1534 ppp_recv_lock(ppp); 1535 stats64->rx_packets = ppp->stats64.rx_packets; 1536 stats64->rx_bytes = ppp->stats64.rx_bytes; 1537 ppp_recv_unlock(ppp); 1538 1539 ppp_xmit_lock(ppp); 1540 stats64->tx_packets = ppp->stats64.tx_packets; 1541 stats64->tx_bytes = ppp->stats64.tx_bytes; 1542 ppp_xmit_unlock(ppp); 1543 1544 stats64->rx_errors = dev->stats.rx_errors; 1545 stats64->tx_errors = dev->stats.tx_errors; 1546 stats64->rx_dropped = dev->stats.rx_dropped; 1547 stats64->tx_dropped = dev->stats.tx_dropped; 1548 stats64->rx_length_errors = dev->stats.rx_length_errors; 1549 } 1550 1551 static int ppp_dev_init(struct net_device *dev) 1552 { 1553 struct ppp *ppp; 1554 1555 netdev_lockdep_set_classes(dev); 1556 1557 ppp = netdev_priv(dev); 1558 /* Let the netdevice take a reference on the ppp file. This ensures 1559 * that ppp_destroy_interface() won't run before the device gets 1560 * unregistered. 1561 */ 1562 refcount_inc(&ppp->file.refcnt); 1563 1564 return 0; 1565 } 1566 1567 static void ppp_dev_uninit(struct net_device *dev) 1568 { 1569 struct ppp *ppp = netdev_priv(dev); 1570 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1571 1572 ppp_lock(ppp); 1573 ppp->closing = 1; 1574 ppp_unlock(ppp); 1575 1576 mutex_lock(&pn->all_ppp_mutex); 1577 unit_put(&pn->units_idr, ppp->file.index); 1578 mutex_unlock(&pn->all_ppp_mutex); 1579 1580 ppp->owner = NULL; 1581 1582 ppp->file.dead = 1; 1583 wake_up_interruptible(&ppp->file.rwait); 1584 } 1585 1586 static void ppp_dev_priv_destructor(struct net_device *dev) 1587 { 1588 struct ppp *ppp; 1589 1590 ppp = netdev_priv(dev); 1591 if (refcount_dec_and_test(&ppp->file.refcnt)) 1592 ppp_destroy_interface(ppp); 1593 } 1594 1595 static int ppp_fill_forward_path(struct net_device_path_ctx *ctx, 1596 struct net_device_path *path) 1597 { 1598 struct ppp *ppp = netdev_priv(ctx->dev); 1599 struct ppp_channel *chan; 1600 struct channel *pch; 1601 1602 if (ppp->flags & SC_MULTILINK) 1603 return -EOPNOTSUPP; 1604 1605 if (list_empty(&ppp->channels)) 1606 return -ENODEV; 1607 1608 pch = list_first_entry(&ppp->channels, struct channel, clist); 1609 chan = pch->chan; 1610 if (!chan->ops->fill_forward_path) 1611 return -EOPNOTSUPP; 1612 1613 return chan->ops->fill_forward_path(ctx, path, chan); 1614 } 1615 1616 static const struct net_device_ops ppp_netdev_ops = { 1617 .ndo_init = ppp_dev_init, 1618 .ndo_uninit = ppp_dev_uninit, 1619 .ndo_start_xmit = ppp_start_xmit, 1620 .ndo_siocdevprivate = ppp_net_siocdevprivate, 1621 .ndo_get_stats64 = ppp_get_stats64, 1622 .ndo_fill_forward_path = ppp_fill_forward_path, 1623 }; 1624 1625 static struct device_type ppp_type = { 1626 .name = "ppp", 1627 }; 1628 1629 static void ppp_setup(struct net_device *dev) 1630 { 1631 dev->netdev_ops = &ppp_netdev_ops; 1632 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1633 1634 dev->features |= NETIF_F_LLTX; 1635 1636 dev->hard_header_len = PPP_HDRLEN; 1637 dev->mtu = PPP_MRU; 1638 dev->addr_len = 0; 1639 dev->tx_queue_len = 3; 1640 dev->type = ARPHRD_PPP; 1641 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1642 dev->priv_destructor = ppp_dev_priv_destructor; 1643 netif_keep_dst(dev); 1644 } 1645 1646 /* 1647 * Transmit-side routines. 1648 */ 1649 1650 /* Called to do any work queued up on the transmit side that can now be done */ 1651 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1652 { 1653 ppp_xmit_lock(ppp); 1654 if (!ppp->closing) { 1655 ppp_push(ppp); 1656 1657 if (skb) 1658 skb_queue_tail(&ppp->file.xq, skb); 1659 while (!ppp->xmit_pending && 1660 (skb = skb_dequeue(&ppp->file.xq))) 1661 ppp_send_frame(ppp, skb); 1662 /* If there's no work left to do, tell the core net 1663 code that we can accept some more. */ 1664 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1665 netif_wake_queue(ppp->dev); 1666 else 1667 netif_stop_queue(ppp->dev); 1668 } else { 1669 kfree_skb(skb); 1670 } 1671 ppp_xmit_unlock(ppp); 1672 } 1673 1674 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1675 { 1676 local_bh_disable(); 1677 1678 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1679 goto err; 1680 1681 (*this_cpu_ptr(ppp->xmit_recursion))++; 1682 __ppp_xmit_process(ppp, skb); 1683 (*this_cpu_ptr(ppp->xmit_recursion))--; 1684 1685 local_bh_enable(); 1686 1687 return; 1688 1689 err: 1690 local_bh_enable(); 1691 1692 kfree_skb(skb); 1693 1694 if (net_ratelimit()) 1695 netdev_err(ppp->dev, "recursion detected\n"); 1696 } 1697 1698 static inline struct sk_buff * 1699 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1700 { 1701 struct sk_buff *new_skb; 1702 int len; 1703 int new_skb_size = ppp->dev->mtu + 1704 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1705 int compressor_skb_size = ppp->dev->mtu + 1706 ppp->xcomp->comp_extra + PPP_HDRLEN; 1707 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1708 if (!new_skb) { 1709 if (net_ratelimit()) 1710 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1711 return NULL; 1712 } 1713 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1714 skb_reserve(new_skb, 1715 ppp->dev->hard_header_len - PPP_HDRLEN); 1716 1717 /* compressor still expects A/C bytes in hdr */ 1718 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1719 new_skb->data, skb->len + 2, 1720 compressor_skb_size); 1721 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1722 consume_skb(skb); 1723 skb = new_skb; 1724 skb_put(skb, len); 1725 skb_pull(skb, 2); /* pull off A/C bytes */ 1726 } else if (len == 0) { 1727 /* didn't compress, or CCP not up yet */ 1728 consume_skb(new_skb); 1729 new_skb = skb; 1730 } else { 1731 /* 1732 * (len < 0) 1733 * MPPE requires that we do not send unencrypted 1734 * frames. The compressor will return -1 if we 1735 * should drop the frame. We cannot simply test 1736 * the compress_proto because MPPE and MPPC share 1737 * the same number. 1738 */ 1739 if (net_ratelimit()) 1740 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1741 kfree_skb(skb); 1742 consume_skb(new_skb); 1743 new_skb = NULL; 1744 } 1745 return new_skb; 1746 } 1747 1748 /* 1749 * Compress and send a frame. 1750 * The caller should have locked the xmit path, 1751 * and xmit_pending should be 0. 1752 */ 1753 static void 1754 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1755 { 1756 int proto = PPP_PROTO(skb); 1757 struct sk_buff *new_skb; 1758 int len; 1759 unsigned char *cp; 1760 1761 skb->dev = ppp->dev; 1762 1763 if (proto < 0x8000) { 1764 #ifdef CONFIG_PPP_FILTER 1765 /* check if we should pass this packet */ 1766 /* the filter instructions are constructed assuming 1767 a four-byte PPP header on each packet */ 1768 *(u8 *)skb_push(skb, 2) = 1; 1769 if (ppp->pass_filter && 1770 bpf_prog_run(ppp->pass_filter, skb) == 0) { 1771 if (ppp->debug & 1) 1772 netdev_printk(KERN_DEBUG, ppp->dev, 1773 "PPP: outbound frame " 1774 "not passed\n"); 1775 kfree_skb(skb); 1776 return; 1777 } 1778 /* if this packet passes the active filter, record the time */ 1779 if (!(ppp->active_filter && 1780 bpf_prog_run(ppp->active_filter, skb) == 0)) 1781 ppp->last_xmit = jiffies; 1782 skb_pull(skb, 2); 1783 #else 1784 /* for data packets, record the time */ 1785 ppp->last_xmit = jiffies; 1786 #endif /* CONFIG_PPP_FILTER */ 1787 } 1788 1789 ++ppp->stats64.tx_packets; 1790 ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN; 1791 1792 switch (proto) { 1793 case PPP_IP: 1794 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1795 break; 1796 /* try to do VJ TCP header compression */ 1797 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1798 GFP_ATOMIC); 1799 if (!new_skb) { 1800 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1801 goto drop; 1802 } 1803 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1804 cp = skb->data + 2; 1805 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1806 new_skb->data + 2, &cp, 1807 !(ppp->flags & SC_NO_TCP_CCID)); 1808 if (cp == skb->data + 2) { 1809 /* didn't compress */ 1810 consume_skb(new_skb); 1811 } else { 1812 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1813 proto = PPP_VJC_COMP; 1814 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1815 } else { 1816 proto = PPP_VJC_UNCOMP; 1817 cp[0] = skb->data[2]; 1818 } 1819 consume_skb(skb); 1820 skb = new_skb; 1821 cp = skb_put(skb, len + 2); 1822 cp[0] = 0; 1823 cp[1] = proto; 1824 } 1825 break; 1826 1827 case PPP_CCP: 1828 /* peek at outbound CCP frames */ 1829 ppp_ccp_peek(ppp, skb, 0); 1830 break; 1831 } 1832 1833 /* try to do packet compression */ 1834 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1835 proto != PPP_LCP && proto != PPP_CCP) { 1836 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1837 if (net_ratelimit()) 1838 netdev_err(ppp->dev, 1839 "ppp: compression required but " 1840 "down - pkt dropped.\n"); 1841 goto drop; 1842 } 1843 skb = pad_compress_skb(ppp, skb); 1844 if (!skb) 1845 goto drop; 1846 } 1847 1848 /* 1849 * If we are waiting for traffic (demand dialling), 1850 * queue it up for pppd to receive. 1851 */ 1852 if (ppp->flags & SC_LOOP_TRAFFIC) { 1853 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1854 goto drop; 1855 skb_queue_tail(&ppp->file.rq, skb); 1856 wake_up_interruptible(&ppp->file.rwait); 1857 return; 1858 } 1859 1860 ppp->xmit_pending = skb; 1861 ppp_push(ppp); 1862 return; 1863 1864 drop: 1865 kfree_skb(skb); 1866 ++ppp->dev->stats.tx_errors; 1867 } 1868 1869 /* 1870 * Try to send the frame in xmit_pending. 1871 * The caller should have the xmit path locked. 1872 */ 1873 static void 1874 ppp_push(struct ppp *ppp) 1875 { 1876 struct list_head *list; 1877 struct channel *pch; 1878 struct sk_buff *skb = ppp->xmit_pending; 1879 1880 if (!skb) 1881 return; 1882 1883 list = &ppp->channels; 1884 if (list_empty(list)) { 1885 /* nowhere to send the packet, just drop it */ 1886 ppp->xmit_pending = NULL; 1887 kfree_skb(skb); 1888 return; 1889 } 1890 1891 if ((ppp->flags & SC_MULTILINK) == 0) { 1892 /* not doing multilink: send it down the first channel */ 1893 list = list->next; 1894 pch = list_entry(list, struct channel, clist); 1895 1896 spin_lock(&pch->downl); 1897 if (pch->chan) { 1898 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1899 ppp->xmit_pending = NULL; 1900 } else { 1901 /* channel got unregistered */ 1902 kfree_skb(skb); 1903 ppp->xmit_pending = NULL; 1904 } 1905 spin_unlock(&pch->downl); 1906 return; 1907 } 1908 1909 #ifdef CONFIG_PPP_MULTILINK 1910 /* Multilink: fragment the packet over as many links 1911 as can take the packet at the moment. */ 1912 if (!ppp_mp_explode(ppp, skb)) 1913 return; 1914 #endif /* CONFIG_PPP_MULTILINK */ 1915 1916 ppp->xmit_pending = NULL; 1917 kfree_skb(skb); 1918 } 1919 1920 #ifdef CONFIG_PPP_MULTILINK 1921 static bool mp_protocol_compress __read_mostly = true; 1922 module_param(mp_protocol_compress, bool, 0644); 1923 MODULE_PARM_DESC(mp_protocol_compress, 1924 "compress protocol id in multilink fragments"); 1925 1926 /* 1927 * Divide a packet to be transmitted into fragments and 1928 * send them out the individual links. 1929 */ 1930 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1931 { 1932 int len, totlen; 1933 int i, bits, hdrlen, mtu; 1934 int flen; 1935 int navail, nfree, nzero; 1936 int nbigger; 1937 int totspeed; 1938 int totfree; 1939 unsigned char *p, *q; 1940 struct list_head *list; 1941 struct channel *pch; 1942 struct sk_buff *frag; 1943 struct ppp_channel *chan; 1944 1945 totspeed = 0; /*total bitrate of the bundle*/ 1946 nfree = 0; /* # channels which have no packet already queued */ 1947 navail = 0; /* total # of usable channels (not deregistered) */ 1948 nzero = 0; /* number of channels with zero speed associated*/ 1949 totfree = 0; /*total # of channels available and 1950 *having no queued packets before 1951 *starting the fragmentation*/ 1952 1953 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1954 i = 0; 1955 list_for_each_entry(pch, &ppp->channels, clist) { 1956 if (pch->chan) { 1957 pch->avail = 1; 1958 navail++; 1959 pch->speed = pch->chan->speed; 1960 } else { 1961 pch->avail = 0; 1962 } 1963 if (pch->avail) { 1964 if (skb_queue_empty(&pch->file.xq) || 1965 !pch->had_frag) { 1966 if (pch->speed == 0) 1967 nzero++; 1968 else 1969 totspeed += pch->speed; 1970 1971 pch->avail = 2; 1972 ++nfree; 1973 ++totfree; 1974 } 1975 if (!pch->had_frag && i < ppp->nxchan) 1976 ppp->nxchan = i; 1977 } 1978 ++i; 1979 } 1980 /* 1981 * Don't start sending this packet unless at least half of 1982 * the channels are free. This gives much better TCP 1983 * performance if we have a lot of channels. 1984 */ 1985 if (nfree == 0 || nfree < navail / 2) 1986 return 0; /* can't take now, leave it in xmit_pending */ 1987 1988 /* Do protocol field compression */ 1989 p = skb->data; 1990 len = skb->len; 1991 if (*p == 0 && mp_protocol_compress) { 1992 ++p; 1993 --len; 1994 } 1995 1996 totlen = len; 1997 nbigger = len % nfree; 1998 1999 /* skip to the channel after the one we last used 2000 and start at that one */ 2001 list = &ppp->channels; 2002 for (i = 0; i < ppp->nxchan; ++i) { 2003 list = list->next; 2004 if (list == &ppp->channels) { 2005 i = 0; 2006 break; 2007 } 2008 } 2009 2010 /* create a fragment for each channel */ 2011 bits = B; 2012 while (len > 0) { 2013 list = list->next; 2014 if (list == &ppp->channels) { 2015 i = 0; 2016 continue; 2017 } 2018 pch = list_entry(list, struct channel, clist); 2019 ++i; 2020 if (!pch->avail) 2021 continue; 2022 2023 /* 2024 * Skip this channel if it has a fragment pending already and 2025 * we haven't given a fragment to all of the free channels. 2026 */ 2027 if (pch->avail == 1) { 2028 if (nfree > 0) 2029 continue; 2030 } else { 2031 pch->avail = 1; 2032 } 2033 2034 /* check the channel's mtu and whether it is still attached. */ 2035 spin_lock(&pch->downl); 2036 if (pch->chan == NULL) { 2037 /* can't use this channel, it's being deregistered */ 2038 if (pch->speed == 0) 2039 nzero--; 2040 else 2041 totspeed -= pch->speed; 2042 2043 spin_unlock(&pch->downl); 2044 pch->avail = 0; 2045 totlen = len; 2046 totfree--; 2047 nfree--; 2048 if (--navail == 0) 2049 break; 2050 continue; 2051 } 2052 2053 /* 2054 *if the channel speed is not set divide 2055 *the packet evenly among the free channels; 2056 *otherwise divide it according to the speed 2057 *of the channel we are going to transmit on 2058 */ 2059 flen = len; 2060 if (nfree > 0) { 2061 if (pch->speed == 0) { 2062 flen = len/nfree; 2063 if (nbigger > 0) { 2064 flen++; 2065 nbigger--; 2066 } 2067 } else { 2068 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 2069 ((totspeed*totfree)/pch->speed)) - hdrlen; 2070 if (nbigger > 0) { 2071 flen += ((totfree - nzero)*pch->speed)/totspeed; 2072 nbigger -= ((totfree - nzero)*pch->speed)/ 2073 totspeed; 2074 } 2075 } 2076 nfree--; 2077 } 2078 2079 /* 2080 *check if we are on the last channel or 2081 *we exceded the length of the data to 2082 *fragment 2083 */ 2084 if ((nfree <= 0) || (flen > len)) 2085 flen = len; 2086 /* 2087 *it is not worth to tx on slow channels: 2088 *in that case from the resulting flen according to the 2089 *above formula will be equal or less than zero. 2090 *Skip the channel in this case 2091 */ 2092 if (flen <= 0) { 2093 pch->avail = 2; 2094 spin_unlock(&pch->downl); 2095 continue; 2096 } 2097 2098 /* 2099 * hdrlen includes the 2-byte PPP protocol field, but the 2100 * MTU counts only the payload excluding the protocol field. 2101 * (RFC1661 Section 2) 2102 */ 2103 mtu = pch->chan->mtu - (hdrlen - 2); 2104 if (mtu < 4) 2105 mtu = 4; 2106 if (flen > mtu) 2107 flen = mtu; 2108 if (flen == len) 2109 bits |= E; 2110 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 2111 if (!frag) 2112 goto noskb; 2113 q = skb_put(frag, flen + hdrlen); 2114 2115 /* make the MP header */ 2116 put_unaligned_be16(PPP_MP, q); 2117 if (ppp->flags & SC_MP_XSHORTSEQ) { 2118 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 2119 q[3] = ppp->nxseq; 2120 } else { 2121 q[2] = bits; 2122 q[3] = ppp->nxseq >> 16; 2123 q[4] = ppp->nxseq >> 8; 2124 q[5] = ppp->nxseq; 2125 } 2126 2127 memcpy(q + hdrlen, p, flen); 2128 2129 /* try to send it down the channel */ 2130 chan = pch->chan; 2131 if (!skb_queue_empty(&pch->file.xq) || 2132 !chan->ops->start_xmit(chan, frag)) 2133 skb_queue_tail(&pch->file.xq, frag); 2134 pch->had_frag = 1; 2135 p += flen; 2136 len -= flen; 2137 ++ppp->nxseq; 2138 bits = 0; 2139 spin_unlock(&pch->downl); 2140 } 2141 ppp->nxchan = i; 2142 2143 return 1; 2144 2145 noskb: 2146 spin_unlock(&pch->downl); 2147 if (ppp->debug & 1) 2148 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 2149 ++ppp->dev->stats.tx_errors; 2150 ++ppp->nxseq; 2151 return 1; /* abandon the frame */ 2152 } 2153 #endif /* CONFIG_PPP_MULTILINK */ 2154 2155 /* Try to send data out on a channel */ 2156 static void __ppp_channel_push(struct channel *pch) 2157 { 2158 struct sk_buff *skb; 2159 struct ppp *ppp; 2160 2161 spin_lock(&pch->downl); 2162 if (pch->chan) { 2163 while (!skb_queue_empty(&pch->file.xq)) { 2164 skb = skb_dequeue(&pch->file.xq); 2165 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2166 /* put the packet back and try again later */ 2167 skb_queue_head(&pch->file.xq, skb); 2168 break; 2169 } 2170 } 2171 } else { 2172 /* channel got deregistered */ 2173 skb_queue_purge(&pch->file.xq); 2174 } 2175 spin_unlock(&pch->downl); 2176 /* see if there is anything from the attached unit to be sent */ 2177 if (skb_queue_empty(&pch->file.xq)) { 2178 ppp = pch->ppp; 2179 if (ppp) 2180 __ppp_xmit_process(ppp, NULL); 2181 } 2182 } 2183 2184 static void ppp_channel_push(struct channel *pch) 2185 { 2186 read_lock_bh(&pch->upl); 2187 if (pch->ppp) { 2188 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 2189 __ppp_channel_push(pch); 2190 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 2191 } else { 2192 __ppp_channel_push(pch); 2193 } 2194 read_unlock_bh(&pch->upl); 2195 } 2196 2197 /* 2198 * Receive-side routines. 2199 */ 2200 2201 struct ppp_mp_skb_parm { 2202 u32 sequence; 2203 u8 BEbits; 2204 }; 2205 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2206 2207 static inline void 2208 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2209 { 2210 ppp_recv_lock(ppp); 2211 if (!ppp->closing) 2212 ppp_receive_frame(ppp, skb, pch); 2213 else 2214 kfree_skb(skb); 2215 ppp_recv_unlock(ppp); 2216 } 2217 2218 /** 2219 * __ppp_decompress_proto - Decompress protocol field, slim version. 2220 * @skb: Socket buffer where protocol field should be decompressed. It must have 2221 * at least 1 byte of head room and 1 byte of linear data. First byte of 2222 * data must be a protocol field byte. 2223 * 2224 * Decompress protocol field in PPP header if it's compressed, e.g. when 2225 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2226 * length are done in this function. 2227 */ 2228 static void __ppp_decompress_proto(struct sk_buff *skb) 2229 { 2230 if (skb->data[0] & 0x01) 2231 *(u8 *)skb_push(skb, 1) = 0x00; 2232 } 2233 2234 /** 2235 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2236 * @skb: Socket buffer where protocol field should be decompressed. First byte 2237 * of data must be a protocol field byte. 2238 * 2239 * Decompress protocol field in PPP header if it's compressed, e.g. when 2240 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2241 * sure that skb data room is sufficient for Protocol field, before and after 2242 * decompression. 2243 * 2244 * Return: true - decompressed successfully, false - not enough room in skb. 2245 */ 2246 static bool ppp_decompress_proto(struct sk_buff *skb) 2247 { 2248 /* At least one byte should be present (if protocol is compressed) */ 2249 if (!pskb_may_pull(skb, 1)) 2250 return false; 2251 2252 __ppp_decompress_proto(skb); 2253 2254 /* Protocol field should occupy 2 bytes when not compressed */ 2255 return pskb_may_pull(skb, 2); 2256 } 2257 2258 /* Attempt to handle a frame via. a bridged channel, if one exists. 2259 * If the channel is bridged, the frame is consumed by the bridge. 2260 * If not, the caller must handle the frame by normal recv mechanisms. 2261 * Returns true if the frame is consumed, false otherwise. 2262 */ 2263 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) 2264 { 2265 struct channel *pchb; 2266 2267 rcu_read_lock(); 2268 pchb = rcu_dereference(pch->bridge); 2269 if (!pchb) 2270 goto out_rcu; 2271 2272 spin_lock(&pchb->downl); 2273 if (!pchb->chan) { 2274 /* channel got unregistered */ 2275 kfree_skb(skb); 2276 goto outl; 2277 } 2278 2279 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); 2280 if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) 2281 kfree_skb(skb); 2282 2283 outl: 2284 spin_unlock(&pchb->downl); 2285 out_rcu: 2286 rcu_read_unlock(); 2287 2288 /* If pchb is set then we've consumed the packet */ 2289 return !!pchb; 2290 } 2291 2292 void 2293 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2294 { 2295 struct channel *pch = chan->ppp; 2296 int proto; 2297 2298 if (!pch) { 2299 kfree_skb(skb); 2300 return; 2301 } 2302 2303 /* If the channel is bridged, transmit via. bridge */ 2304 if (ppp_channel_bridge_input(pch, skb)) 2305 return; 2306 2307 read_lock_bh(&pch->upl); 2308 if (!ppp_decompress_proto(skb)) { 2309 kfree_skb(skb); 2310 if (pch->ppp) { 2311 ++pch->ppp->dev->stats.rx_length_errors; 2312 ppp_receive_error(pch->ppp); 2313 } 2314 goto done; 2315 } 2316 2317 proto = PPP_PROTO(skb); 2318 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2319 /* put it on the channel queue */ 2320 skb_queue_tail(&pch->file.rq, skb); 2321 /* drop old frames if queue too long */ 2322 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2323 (skb = skb_dequeue(&pch->file.rq))) 2324 kfree_skb(skb); 2325 wake_up_interruptible(&pch->file.rwait); 2326 } else { 2327 ppp_do_recv(pch->ppp, skb, pch); 2328 } 2329 2330 done: 2331 read_unlock_bh(&pch->upl); 2332 } 2333 2334 /* Put a 0-length skb in the receive queue as an error indication */ 2335 void 2336 ppp_input_error(struct ppp_channel *chan, int code) 2337 { 2338 struct channel *pch = chan->ppp; 2339 struct sk_buff *skb; 2340 2341 if (!pch) 2342 return; 2343 2344 read_lock_bh(&pch->upl); 2345 if (pch->ppp) { 2346 skb = alloc_skb(0, GFP_ATOMIC); 2347 if (skb) { 2348 skb->len = 0; /* probably unnecessary */ 2349 skb->cb[0] = code; 2350 ppp_do_recv(pch->ppp, skb, pch); 2351 } 2352 } 2353 read_unlock_bh(&pch->upl); 2354 } 2355 2356 /* 2357 * We come in here to process a received frame. 2358 * The receive side of the ppp unit is locked. 2359 */ 2360 static void 2361 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2362 { 2363 /* note: a 0-length skb is used as an error indication */ 2364 if (skb->len > 0) { 2365 skb_checksum_complete_unset(skb); 2366 #ifdef CONFIG_PPP_MULTILINK 2367 /* XXX do channel-level decompression here */ 2368 if (PPP_PROTO(skb) == PPP_MP) 2369 ppp_receive_mp_frame(ppp, skb, pch); 2370 else 2371 #endif /* CONFIG_PPP_MULTILINK */ 2372 ppp_receive_nonmp_frame(ppp, skb); 2373 } else { 2374 kfree_skb(skb); 2375 ppp_receive_error(ppp); 2376 } 2377 } 2378 2379 static void 2380 ppp_receive_error(struct ppp *ppp) 2381 { 2382 ++ppp->dev->stats.rx_errors; 2383 if (ppp->vj) 2384 slhc_toss(ppp->vj); 2385 } 2386 2387 static void 2388 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2389 { 2390 struct sk_buff *ns; 2391 int proto, len, npi; 2392 2393 /* 2394 * Decompress the frame, if compressed. 2395 * Note that some decompressors need to see uncompressed frames 2396 * that come in as well as compressed frames. 2397 */ 2398 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2399 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2400 skb = ppp_decompress_frame(ppp, skb); 2401 2402 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2403 goto err; 2404 2405 /* At this point the "Protocol" field MUST be decompressed, either in 2406 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2407 */ 2408 proto = PPP_PROTO(skb); 2409 switch (proto) { 2410 case PPP_VJC_COMP: 2411 /* decompress VJ compressed packets */ 2412 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2413 goto err; 2414 2415 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2416 /* copy to a new sk_buff with more tailroom */ 2417 ns = dev_alloc_skb(skb->len + 128); 2418 if (!ns) { 2419 netdev_err(ppp->dev, "PPP: no memory " 2420 "(VJ decomp)\n"); 2421 goto err; 2422 } 2423 skb_reserve(ns, 2); 2424 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2425 consume_skb(skb); 2426 skb = ns; 2427 } 2428 else 2429 skb->ip_summed = CHECKSUM_NONE; 2430 2431 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2432 if (len <= 0) { 2433 netdev_printk(KERN_DEBUG, ppp->dev, 2434 "PPP: VJ decompression error\n"); 2435 goto err; 2436 } 2437 len += 2; 2438 if (len > skb->len) 2439 skb_put(skb, len - skb->len); 2440 else if (len < skb->len) 2441 skb_trim(skb, len); 2442 proto = PPP_IP; 2443 break; 2444 2445 case PPP_VJC_UNCOMP: 2446 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2447 goto err; 2448 2449 /* Until we fix the decompressor need to make sure 2450 * data portion is linear. 2451 */ 2452 if (!pskb_may_pull(skb, skb->len)) 2453 goto err; 2454 2455 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2456 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2457 goto err; 2458 } 2459 proto = PPP_IP; 2460 break; 2461 2462 case PPP_CCP: 2463 ppp_ccp_peek(ppp, skb, 1); 2464 break; 2465 } 2466 2467 ++ppp->stats64.rx_packets; 2468 ppp->stats64.rx_bytes += skb->len - 2; 2469 2470 npi = proto_to_npindex(proto); 2471 if (npi < 0) { 2472 /* control or unknown frame - pass it to pppd */ 2473 skb_queue_tail(&ppp->file.rq, skb); 2474 /* limit queue length by dropping old frames */ 2475 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2476 (skb = skb_dequeue(&ppp->file.rq))) 2477 kfree_skb(skb); 2478 /* wake up any process polling or blocking on read */ 2479 wake_up_interruptible(&ppp->file.rwait); 2480 2481 } else { 2482 /* network protocol frame - give it to the kernel */ 2483 2484 #ifdef CONFIG_PPP_FILTER 2485 /* check if the packet passes the pass and active filters */ 2486 /* the filter instructions are constructed assuming 2487 a four-byte PPP header on each packet */ 2488 if (ppp->pass_filter || ppp->active_filter) { 2489 if (skb_unclone(skb, GFP_ATOMIC)) 2490 goto err; 2491 2492 *(u8 *)skb_push(skb, 2) = 0; 2493 if (ppp->pass_filter && 2494 bpf_prog_run(ppp->pass_filter, skb) == 0) { 2495 if (ppp->debug & 1) 2496 netdev_printk(KERN_DEBUG, ppp->dev, 2497 "PPP: inbound frame " 2498 "not passed\n"); 2499 kfree_skb(skb); 2500 return; 2501 } 2502 if (!(ppp->active_filter && 2503 bpf_prog_run(ppp->active_filter, skb) == 0)) 2504 ppp->last_recv = jiffies; 2505 __skb_pull(skb, 2); 2506 } else 2507 #endif /* CONFIG_PPP_FILTER */ 2508 ppp->last_recv = jiffies; 2509 2510 if ((ppp->dev->flags & IFF_UP) == 0 || 2511 ppp->npmode[npi] != NPMODE_PASS) { 2512 kfree_skb(skb); 2513 } else { 2514 /* chop off protocol */ 2515 skb_pull_rcsum(skb, 2); 2516 skb->dev = ppp->dev; 2517 skb->protocol = htons(npindex_to_ethertype[npi]); 2518 skb_reset_mac_header(skb); 2519 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2520 dev_net(ppp->dev))); 2521 netif_rx(skb); 2522 } 2523 } 2524 return; 2525 2526 err: 2527 kfree_skb(skb); 2528 ppp_receive_error(ppp); 2529 } 2530 2531 static struct sk_buff * 2532 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2533 { 2534 int proto = PPP_PROTO(skb); 2535 struct sk_buff *ns; 2536 int len; 2537 2538 /* Until we fix all the decompressor's need to make sure 2539 * data portion is linear. 2540 */ 2541 if (!pskb_may_pull(skb, skb->len)) 2542 goto err; 2543 2544 if (proto == PPP_COMP) { 2545 int obuff_size; 2546 2547 switch(ppp->rcomp->compress_proto) { 2548 case CI_MPPE: 2549 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2550 break; 2551 default: 2552 obuff_size = ppp->mru + PPP_HDRLEN; 2553 break; 2554 } 2555 2556 ns = dev_alloc_skb(obuff_size); 2557 if (!ns) { 2558 netdev_err(ppp->dev, "ppp_decompress_frame: " 2559 "no memory\n"); 2560 goto err; 2561 } 2562 /* the decompressor still expects the A/C bytes in the hdr */ 2563 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2564 skb->len + 2, ns->data, obuff_size); 2565 if (len < 0) { 2566 /* Pass the compressed frame to pppd as an 2567 error indication. */ 2568 if (len == DECOMP_FATALERROR) 2569 ppp->rstate |= SC_DC_FERROR; 2570 kfree_skb(ns); 2571 goto err; 2572 } 2573 2574 consume_skb(skb); 2575 skb = ns; 2576 skb_put(skb, len); 2577 skb_pull(skb, 2); /* pull off the A/C bytes */ 2578 2579 /* Don't call __ppp_decompress_proto() here, but instead rely on 2580 * corresponding algo (mppe/bsd/deflate) to decompress it. 2581 */ 2582 } else { 2583 /* Uncompressed frame - pass to decompressor so it 2584 can update its dictionary if necessary. */ 2585 if (ppp->rcomp->incomp) 2586 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2587 skb->len + 2); 2588 } 2589 2590 return skb; 2591 2592 err: 2593 ppp->rstate |= SC_DC_ERROR; 2594 ppp_receive_error(ppp); 2595 return skb; 2596 } 2597 2598 #ifdef CONFIG_PPP_MULTILINK 2599 /* 2600 * Receive a multilink frame. 2601 * We put it on the reconstruction queue and then pull off 2602 * as many completed frames as we can. 2603 */ 2604 static void 2605 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2606 { 2607 u32 mask, seq; 2608 struct channel *ch; 2609 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2610 2611 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2612 goto err; /* no good, throw it away */ 2613 2614 /* Decode sequence number and begin/end bits */ 2615 if (ppp->flags & SC_MP_SHORTSEQ) { 2616 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2617 mask = 0xfff; 2618 } else { 2619 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2620 mask = 0xffffff; 2621 } 2622 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2623 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2624 2625 /* 2626 * Do protocol ID decompression on the first fragment of each packet. 2627 * We have to do that here, because ppp_receive_nonmp_frame() expects 2628 * decompressed protocol field. 2629 */ 2630 if (PPP_MP_CB(skb)->BEbits & B) 2631 __ppp_decompress_proto(skb); 2632 2633 /* 2634 * Expand sequence number to 32 bits, making it as close 2635 * as possible to ppp->minseq. 2636 */ 2637 seq |= ppp->minseq & ~mask; 2638 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2639 seq += mask + 1; 2640 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2641 seq -= mask + 1; /* should never happen */ 2642 PPP_MP_CB(skb)->sequence = seq; 2643 pch->lastseq = seq; 2644 2645 /* 2646 * If this packet comes before the next one we were expecting, 2647 * drop it. 2648 */ 2649 if (seq_before(seq, ppp->nextseq)) { 2650 kfree_skb(skb); 2651 ++ppp->dev->stats.rx_dropped; 2652 ppp_receive_error(ppp); 2653 return; 2654 } 2655 2656 /* 2657 * Reevaluate minseq, the minimum over all channels of the 2658 * last sequence number received on each channel. Because of 2659 * the increasing sequence number rule, we know that any fragment 2660 * before `minseq' which hasn't arrived is never going to arrive. 2661 * The list of channels can't change because we have the receive 2662 * side of the ppp unit locked. 2663 */ 2664 list_for_each_entry(ch, &ppp->channels, clist) { 2665 if (seq_before(ch->lastseq, seq)) 2666 seq = ch->lastseq; 2667 } 2668 if (seq_before(ppp->minseq, seq)) 2669 ppp->minseq = seq; 2670 2671 /* Put the fragment on the reconstruction queue */ 2672 ppp_mp_insert(ppp, skb); 2673 2674 /* If the queue is getting long, don't wait any longer for packets 2675 before the start of the queue. */ 2676 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2677 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2678 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2679 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2680 } 2681 2682 /* Pull completed packets off the queue and receive them. */ 2683 while ((skb = ppp_mp_reconstruct(ppp))) { 2684 if (pskb_may_pull(skb, 2)) 2685 ppp_receive_nonmp_frame(ppp, skb); 2686 else { 2687 ++ppp->dev->stats.rx_length_errors; 2688 kfree_skb(skb); 2689 ppp_receive_error(ppp); 2690 } 2691 } 2692 2693 return; 2694 2695 err: 2696 kfree_skb(skb); 2697 ppp_receive_error(ppp); 2698 } 2699 2700 /* 2701 * Insert a fragment on the MP reconstruction queue. 2702 * The queue is ordered by increasing sequence number. 2703 */ 2704 static void 2705 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2706 { 2707 struct sk_buff *p; 2708 struct sk_buff_head *list = &ppp->mrq; 2709 u32 seq = PPP_MP_CB(skb)->sequence; 2710 2711 /* N.B. we don't need to lock the list lock because we have the 2712 ppp unit receive-side lock. */ 2713 skb_queue_walk(list, p) { 2714 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2715 break; 2716 } 2717 __skb_queue_before(list, p, skb); 2718 } 2719 2720 /* 2721 * Reconstruct a packet from the MP fragment queue. 2722 * We go through increasing sequence numbers until we find a 2723 * complete packet, or we get to the sequence number for a fragment 2724 * which hasn't arrived but might still do so. 2725 */ 2726 static struct sk_buff * 2727 ppp_mp_reconstruct(struct ppp *ppp) 2728 { 2729 u32 seq = ppp->nextseq; 2730 u32 minseq = ppp->minseq; 2731 struct sk_buff_head *list = &ppp->mrq; 2732 struct sk_buff *p, *tmp; 2733 struct sk_buff *head, *tail; 2734 struct sk_buff *skb = NULL; 2735 int lost = 0, len = 0; 2736 2737 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2738 return NULL; 2739 head = __skb_peek(list); 2740 tail = NULL; 2741 skb_queue_walk_safe(list, p, tmp) { 2742 again: 2743 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2744 /* this can't happen, anyway ignore the skb */ 2745 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2746 "seq %u < %u\n", 2747 PPP_MP_CB(p)->sequence, seq); 2748 __skb_unlink(p, list); 2749 kfree_skb(p); 2750 continue; 2751 } 2752 if (PPP_MP_CB(p)->sequence != seq) { 2753 u32 oldseq; 2754 /* Fragment `seq' is missing. If it is after 2755 minseq, it might arrive later, so stop here. */ 2756 if (seq_after(seq, minseq)) 2757 break; 2758 /* Fragment `seq' is lost, keep going. */ 2759 lost = 1; 2760 oldseq = seq; 2761 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2762 minseq + 1: PPP_MP_CB(p)->sequence; 2763 2764 if (ppp->debug & 1) 2765 netdev_printk(KERN_DEBUG, ppp->dev, 2766 "lost frag %u..%u\n", 2767 oldseq, seq-1); 2768 2769 goto again; 2770 } 2771 2772 /* 2773 * At this point we know that all the fragments from 2774 * ppp->nextseq to seq are either present or lost. 2775 * Also, there are no complete packets in the queue 2776 * that have no missing fragments and end before this 2777 * fragment. 2778 */ 2779 2780 /* B bit set indicates this fragment starts a packet */ 2781 if (PPP_MP_CB(p)->BEbits & B) { 2782 head = p; 2783 lost = 0; 2784 len = 0; 2785 } 2786 2787 len += p->len; 2788 2789 /* Got a complete packet yet? */ 2790 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2791 (PPP_MP_CB(head)->BEbits & B)) { 2792 if (len > ppp->mrru + 2) { 2793 ++ppp->dev->stats.rx_length_errors; 2794 netdev_printk(KERN_DEBUG, ppp->dev, 2795 "PPP: reconstructed packet" 2796 " is too long (%d)\n", len); 2797 } else { 2798 tail = p; 2799 break; 2800 } 2801 ppp->nextseq = seq + 1; 2802 } 2803 2804 /* 2805 * If this is the ending fragment of a packet, 2806 * and we haven't found a complete valid packet yet, 2807 * we can discard up to and including this fragment. 2808 */ 2809 if (PPP_MP_CB(p)->BEbits & E) { 2810 struct sk_buff *tmp2; 2811 2812 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2813 if (ppp->debug & 1) 2814 netdev_printk(KERN_DEBUG, ppp->dev, 2815 "discarding frag %u\n", 2816 PPP_MP_CB(p)->sequence); 2817 __skb_unlink(p, list); 2818 kfree_skb(p); 2819 } 2820 head = skb_peek(list); 2821 if (!head) 2822 break; 2823 } 2824 ++seq; 2825 } 2826 2827 /* If we have a complete packet, copy it all into one skb. */ 2828 if (tail != NULL) { 2829 /* If we have discarded any fragments, 2830 signal a receive error. */ 2831 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2832 skb_queue_walk_safe(list, p, tmp) { 2833 if (p == head) 2834 break; 2835 if (ppp->debug & 1) 2836 netdev_printk(KERN_DEBUG, ppp->dev, 2837 "discarding frag %u\n", 2838 PPP_MP_CB(p)->sequence); 2839 __skb_unlink(p, list); 2840 kfree_skb(p); 2841 } 2842 2843 if (ppp->debug & 1) 2844 netdev_printk(KERN_DEBUG, ppp->dev, 2845 " missed pkts %u..%u\n", 2846 ppp->nextseq, 2847 PPP_MP_CB(head)->sequence-1); 2848 ++ppp->dev->stats.rx_dropped; 2849 ppp_receive_error(ppp); 2850 } 2851 2852 skb = head; 2853 if (head != tail) { 2854 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2855 p = skb_queue_next(list, head); 2856 __skb_unlink(skb, list); 2857 skb_queue_walk_from_safe(list, p, tmp) { 2858 __skb_unlink(p, list); 2859 *fragpp = p; 2860 p->next = NULL; 2861 fragpp = &p->next; 2862 2863 skb->len += p->len; 2864 skb->data_len += p->len; 2865 skb->truesize += p->truesize; 2866 2867 if (p == tail) 2868 break; 2869 } 2870 } else { 2871 __skb_unlink(skb, list); 2872 } 2873 2874 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2875 } 2876 2877 return skb; 2878 } 2879 #endif /* CONFIG_PPP_MULTILINK */ 2880 2881 /* 2882 * Channel interface. 2883 */ 2884 2885 /* Create a new, unattached ppp channel. */ 2886 int ppp_register_channel(struct ppp_channel *chan) 2887 { 2888 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2889 } 2890 2891 /* Create a new, unattached ppp channel for specified net. */ 2892 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2893 { 2894 struct channel *pch; 2895 struct ppp_net *pn; 2896 2897 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2898 if (!pch) 2899 return -ENOMEM; 2900 2901 pn = ppp_pernet(net); 2902 2903 pch->ppp = NULL; 2904 pch->chan = chan; 2905 pch->chan_net = get_net_track(net, &pch->ns_tracker, GFP_KERNEL); 2906 chan->ppp = pch; 2907 init_ppp_file(&pch->file, CHANNEL); 2908 pch->file.hdrlen = chan->hdrlen; 2909 #ifdef CONFIG_PPP_MULTILINK 2910 pch->lastseq = -1; 2911 #endif /* CONFIG_PPP_MULTILINK */ 2912 init_rwsem(&pch->chan_sem); 2913 spin_lock_init(&pch->downl); 2914 rwlock_init(&pch->upl); 2915 2916 spin_lock_bh(&pn->all_channels_lock); 2917 pch->file.index = ++pn->last_channel_index; 2918 list_add(&pch->list, &pn->new_channels); 2919 atomic_inc(&channel_count); 2920 spin_unlock_bh(&pn->all_channels_lock); 2921 2922 return 0; 2923 } 2924 2925 /* 2926 * Return the index of a channel. 2927 */ 2928 int ppp_channel_index(struct ppp_channel *chan) 2929 { 2930 struct channel *pch = chan->ppp; 2931 2932 if (pch) 2933 return pch->file.index; 2934 return -1; 2935 } 2936 2937 /* 2938 * Return the PPP unit number to which a channel is connected. 2939 */ 2940 int ppp_unit_number(struct ppp_channel *chan) 2941 { 2942 struct channel *pch = chan->ppp; 2943 int unit = -1; 2944 2945 if (pch) { 2946 read_lock_bh(&pch->upl); 2947 if (pch->ppp) 2948 unit = pch->ppp->file.index; 2949 read_unlock_bh(&pch->upl); 2950 } 2951 return unit; 2952 } 2953 2954 /* 2955 * Return the PPP device interface name of a channel. 2956 */ 2957 char *ppp_dev_name(struct ppp_channel *chan) 2958 { 2959 struct channel *pch = chan->ppp; 2960 char *name = NULL; 2961 2962 if (pch) { 2963 read_lock_bh(&pch->upl); 2964 if (pch->ppp && pch->ppp->dev) 2965 name = pch->ppp->dev->name; 2966 read_unlock_bh(&pch->upl); 2967 } 2968 return name; 2969 } 2970 2971 2972 /* 2973 * Disconnect a channel from the generic layer. 2974 * This must be called in process context. 2975 */ 2976 void 2977 ppp_unregister_channel(struct ppp_channel *chan) 2978 { 2979 struct channel *pch = chan->ppp; 2980 struct ppp_net *pn; 2981 2982 if (!pch) 2983 return; /* should never happen */ 2984 2985 chan->ppp = NULL; 2986 2987 /* 2988 * This ensures that we have returned from any calls into 2989 * the channel's start_xmit or ioctl routine before we proceed. 2990 */ 2991 down_write(&pch->chan_sem); 2992 spin_lock_bh(&pch->downl); 2993 pch->chan = NULL; 2994 spin_unlock_bh(&pch->downl); 2995 up_write(&pch->chan_sem); 2996 ppp_disconnect_channel(pch); 2997 2998 pn = ppp_pernet(pch->chan_net); 2999 spin_lock_bh(&pn->all_channels_lock); 3000 list_del(&pch->list); 3001 spin_unlock_bh(&pn->all_channels_lock); 3002 3003 ppp_unbridge_channels(pch); 3004 3005 pch->file.dead = 1; 3006 wake_up_interruptible(&pch->file.rwait); 3007 3008 if (refcount_dec_and_test(&pch->file.refcnt)) 3009 ppp_destroy_channel(pch); 3010 } 3011 3012 /* 3013 * Callback from a channel when it can accept more to transmit. 3014 * This should be called at BH/softirq level, not interrupt level. 3015 */ 3016 void 3017 ppp_output_wakeup(struct ppp_channel *chan) 3018 { 3019 struct channel *pch = chan->ppp; 3020 3021 if (!pch) 3022 return; 3023 ppp_channel_push(pch); 3024 } 3025 3026 /* 3027 * Compression control. 3028 */ 3029 3030 /* Process the PPPIOCSCOMPRESS ioctl. */ 3031 static int 3032 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 3033 { 3034 int err = -EFAULT; 3035 struct compressor *cp, *ocomp; 3036 void *state, *ostate; 3037 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 3038 3039 if (data->length > CCP_MAX_OPTION_LENGTH) 3040 goto out; 3041 if (copy_from_user(ccp_option, data->ptr, data->length)) 3042 goto out; 3043 3044 err = -EINVAL; 3045 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 3046 goto out; 3047 3048 cp = try_then_request_module( 3049 find_compressor(ccp_option[0]), 3050 "ppp-compress-%d", ccp_option[0]); 3051 if (!cp) 3052 goto out; 3053 3054 err = -ENOBUFS; 3055 if (data->transmit) { 3056 state = cp->comp_alloc(ccp_option, data->length); 3057 if (state) { 3058 ppp_xmit_lock(ppp); 3059 ppp->xstate &= ~SC_COMP_RUN; 3060 ocomp = ppp->xcomp; 3061 ostate = ppp->xc_state; 3062 ppp->xcomp = cp; 3063 ppp->xc_state = state; 3064 ppp_xmit_unlock(ppp); 3065 if (ostate) { 3066 ocomp->comp_free(ostate); 3067 module_put(ocomp->owner); 3068 } 3069 err = 0; 3070 } else 3071 module_put(cp->owner); 3072 3073 } else { 3074 state = cp->decomp_alloc(ccp_option, data->length); 3075 if (state) { 3076 ppp_recv_lock(ppp); 3077 ppp->rstate &= ~SC_DECOMP_RUN; 3078 ocomp = ppp->rcomp; 3079 ostate = ppp->rc_state; 3080 ppp->rcomp = cp; 3081 ppp->rc_state = state; 3082 ppp_recv_unlock(ppp); 3083 if (ostate) { 3084 ocomp->decomp_free(ostate); 3085 module_put(ocomp->owner); 3086 } 3087 err = 0; 3088 } else 3089 module_put(cp->owner); 3090 } 3091 3092 out: 3093 return err; 3094 } 3095 3096 /* 3097 * Look at a CCP packet and update our state accordingly. 3098 * We assume the caller has the xmit or recv path locked. 3099 */ 3100 static void 3101 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 3102 { 3103 unsigned char *dp; 3104 int len; 3105 3106 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 3107 return; /* no header */ 3108 dp = skb->data + 2; 3109 3110 switch (CCP_CODE(dp)) { 3111 case CCP_CONFREQ: 3112 3113 /* A ConfReq starts negotiation of compression 3114 * in one direction of transmission, 3115 * and hence brings it down...but which way? 3116 * 3117 * Remember: 3118 * A ConfReq indicates what the sender would like to receive 3119 */ 3120 if(inbound) 3121 /* He is proposing what I should send */ 3122 ppp->xstate &= ~SC_COMP_RUN; 3123 else 3124 /* I am proposing to what he should send */ 3125 ppp->rstate &= ~SC_DECOMP_RUN; 3126 3127 break; 3128 3129 case CCP_TERMREQ: 3130 case CCP_TERMACK: 3131 /* 3132 * CCP is going down, both directions of transmission 3133 */ 3134 ppp->rstate &= ~SC_DECOMP_RUN; 3135 ppp->xstate &= ~SC_COMP_RUN; 3136 break; 3137 3138 case CCP_CONFACK: 3139 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 3140 break; 3141 len = CCP_LENGTH(dp); 3142 if (!pskb_may_pull(skb, len + 2)) 3143 return; /* too short */ 3144 dp += CCP_HDRLEN; 3145 len -= CCP_HDRLEN; 3146 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 3147 break; 3148 if (inbound) { 3149 /* we will start receiving compressed packets */ 3150 if (!ppp->rc_state) 3151 break; 3152 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 3153 ppp->file.index, 0, ppp->mru, ppp->debug)) { 3154 ppp->rstate |= SC_DECOMP_RUN; 3155 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 3156 } 3157 } else { 3158 /* we will soon start sending compressed packets */ 3159 if (!ppp->xc_state) 3160 break; 3161 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 3162 ppp->file.index, 0, ppp->debug)) 3163 ppp->xstate |= SC_COMP_RUN; 3164 } 3165 break; 3166 3167 case CCP_RESETACK: 3168 /* reset the [de]compressor */ 3169 if ((ppp->flags & SC_CCP_UP) == 0) 3170 break; 3171 if (inbound) { 3172 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 3173 ppp->rcomp->decomp_reset(ppp->rc_state); 3174 ppp->rstate &= ~SC_DC_ERROR; 3175 } 3176 } else { 3177 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 3178 ppp->xcomp->comp_reset(ppp->xc_state); 3179 } 3180 break; 3181 } 3182 } 3183 3184 /* Free up compression resources. */ 3185 static void 3186 ppp_ccp_closed(struct ppp *ppp) 3187 { 3188 void *xstate, *rstate; 3189 struct compressor *xcomp, *rcomp; 3190 3191 ppp_lock(ppp); 3192 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 3193 ppp->xstate = 0; 3194 xcomp = ppp->xcomp; 3195 xstate = ppp->xc_state; 3196 ppp->xc_state = NULL; 3197 ppp->rstate = 0; 3198 rcomp = ppp->rcomp; 3199 rstate = ppp->rc_state; 3200 ppp->rc_state = NULL; 3201 ppp_unlock(ppp); 3202 3203 if (xstate) { 3204 xcomp->comp_free(xstate); 3205 module_put(xcomp->owner); 3206 } 3207 if (rstate) { 3208 rcomp->decomp_free(rstate); 3209 module_put(rcomp->owner); 3210 } 3211 } 3212 3213 /* List of compressors. */ 3214 static LIST_HEAD(compressor_list); 3215 static DEFINE_SPINLOCK(compressor_list_lock); 3216 3217 struct compressor_entry { 3218 struct list_head list; 3219 struct compressor *comp; 3220 }; 3221 3222 static struct compressor_entry * 3223 find_comp_entry(int proto) 3224 { 3225 struct compressor_entry *ce; 3226 3227 list_for_each_entry(ce, &compressor_list, list) { 3228 if (ce->comp->compress_proto == proto) 3229 return ce; 3230 } 3231 return NULL; 3232 } 3233 3234 /* Register a compressor */ 3235 int 3236 ppp_register_compressor(struct compressor *cp) 3237 { 3238 struct compressor_entry *ce; 3239 int ret; 3240 spin_lock(&compressor_list_lock); 3241 ret = -EEXIST; 3242 if (find_comp_entry(cp->compress_proto)) 3243 goto out; 3244 ret = -ENOMEM; 3245 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 3246 if (!ce) 3247 goto out; 3248 ret = 0; 3249 ce->comp = cp; 3250 list_add(&ce->list, &compressor_list); 3251 out: 3252 spin_unlock(&compressor_list_lock); 3253 return ret; 3254 } 3255 3256 /* Unregister a compressor */ 3257 void 3258 ppp_unregister_compressor(struct compressor *cp) 3259 { 3260 struct compressor_entry *ce; 3261 3262 spin_lock(&compressor_list_lock); 3263 ce = find_comp_entry(cp->compress_proto); 3264 if (ce && ce->comp == cp) { 3265 list_del(&ce->list); 3266 kfree(ce); 3267 } 3268 spin_unlock(&compressor_list_lock); 3269 } 3270 3271 /* Find a compressor. */ 3272 static struct compressor * 3273 find_compressor(int type) 3274 { 3275 struct compressor_entry *ce; 3276 struct compressor *cp = NULL; 3277 3278 spin_lock(&compressor_list_lock); 3279 ce = find_comp_entry(type); 3280 if (ce) { 3281 cp = ce->comp; 3282 if (!try_module_get(cp->owner)) 3283 cp = NULL; 3284 } 3285 spin_unlock(&compressor_list_lock); 3286 return cp; 3287 } 3288 3289 /* 3290 * Miscelleneous stuff. 3291 */ 3292 3293 static void 3294 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3295 { 3296 struct slcompress *vj = ppp->vj; 3297 3298 memset(st, 0, sizeof(*st)); 3299 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3300 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3301 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3302 st->p.ppp_opackets = ppp->stats64.tx_packets; 3303 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3304 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3305 if (!vj) 3306 return; 3307 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3308 st->vj.vjs_compressed = vj->sls_o_compressed; 3309 st->vj.vjs_searches = vj->sls_o_searches; 3310 st->vj.vjs_misses = vj->sls_o_misses; 3311 st->vj.vjs_errorin = vj->sls_i_error; 3312 st->vj.vjs_tossed = vj->sls_i_tossed; 3313 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3314 st->vj.vjs_compressedin = vj->sls_i_compressed; 3315 } 3316 3317 /* 3318 * Stuff for handling the lists of ppp units and channels 3319 * and for initialization. 3320 */ 3321 3322 /* 3323 * Create a new ppp interface unit. Fails if it can't allocate memory 3324 * or if there is already a unit with the requested number. 3325 * unit == -1 means allocate a new number. 3326 */ 3327 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3328 { 3329 struct ppp_config conf = { 3330 .file = file, 3331 .unit = *unit, 3332 .ifname_is_set = false, 3333 }; 3334 struct net_device *dev; 3335 struct ppp *ppp; 3336 int err; 3337 3338 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3339 if (!dev) { 3340 err = -ENOMEM; 3341 goto err; 3342 } 3343 dev_net_set(dev, net); 3344 dev->rtnl_link_ops = &ppp_link_ops; 3345 3346 rtnl_lock(); 3347 3348 err = ppp_dev_configure(net, dev, &conf); 3349 if (err < 0) 3350 goto err_dev; 3351 ppp = netdev_priv(dev); 3352 *unit = ppp->file.index; 3353 3354 rtnl_unlock(); 3355 3356 return 0; 3357 3358 err_dev: 3359 rtnl_unlock(); 3360 free_netdev(dev); 3361 err: 3362 return err; 3363 } 3364 3365 /* 3366 * Initialize a ppp_file structure. 3367 */ 3368 static void 3369 init_ppp_file(struct ppp_file *pf, int kind) 3370 { 3371 pf->kind = kind; 3372 skb_queue_head_init(&pf->xq); 3373 skb_queue_head_init(&pf->rq); 3374 refcount_set(&pf->refcnt, 1); 3375 init_waitqueue_head(&pf->rwait); 3376 } 3377 3378 /* 3379 * Free the memory used by a ppp unit. This is only called once 3380 * there are no channels connected to the unit and no file structs 3381 * that reference the unit. 3382 */ 3383 static void ppp_destroy_interface(struct ppp *ppp) 3384 { 3385 atomic_dec(&ppp_unit_count); 3386 3387 if (!ppp->file.dead || ppp->n_channels) { 3388 /* "can't happen" */ 3389 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3390 "but dead=%d n_channels=%d !\n", 3391 ppp, ppp->file.dead, ppp->n_channels); 3392 return; 3393 } 3394 3395 ppp_ccp_closed(ppp); 3396 if (ppp->vj) { 3397 slhc_free(ppp->vj); 3398 ppp->vj = NULL; 3399 } 3400 skb_queue_purge(&ppp->file.xq); 3401 skb_queue_purge(&ppp->file.rq); 3402 #ifdef CONFIG_PPP_MULTILINK 3403 skb_queue_purge(&ppp->mrq); 3404 #endif /* CONFIG_PPP_MULTILINK */ 3405 #ifdef CONFIG_PPP_FILTER 3406 if (ppp->pass_filter) { 3407 bpf_prog_destroy(ppp->pass_filter); 3408 ppp->pass_filter = NULL; 3409 } 3410 3411 if (ppp->active_filter) { 3412 bpf_prog_destroy(ppp->active_filter); 3413 ppp->active_filter = NULL; 3414 } 3415 #endif /* CONFIG_PPP_FILTER */ 3416 3417 kfree_skb(ppp->xmit_pending); 3418 free_percpu(ppp->xmit_recursion); 3419 3420 free_netdev(ppp->dev); 3421 } 3422 3423 /* 3424 * Locate an existing ppp unit. 3425 * The caller should have locked the all_ppp_mutex. 3426 */ 3427 static struct ppp * 3428 ppp_find_unit(struct ppp_net *pn, int unit) 3429 { 3430 return unit_find(&pn->units_idr, unit); 3431 } 3432 3433 /* 3434 * Locate an existing ppp channel. 3435 * The caller should have locked the all_channels_lock. 3436 * First we look in the new_channels list, then in the 3437 * all_channels list. If found in the new_channels list, 3438 * we move it to the all_channels list. This is for speed 3439 * when we have a lot of channels in use. 3440 */ 3441 static struct channel * 3442 ppp_find_channel(struct ppp_net *pn, int unit) 3443 { 3444 struct channel *pch; 3445 3446 list_for_each_entry(pch, &pn->new_channels, list) { 3447 if (pch->file.index == unit) { 3448 list_move(&pch->list, &pn->all_channels); 3449 return pch; 3450 } 3451 } 3452 3453 list_for_each_entry(pch, &pn->all_channels, list) { 3454 if (pch->file.index == unit) 3455 return pch; 3456 } 3457 3458 return NULL; 3459 } 3460 3461 /* 3462 * Connect a PPP channel to a PPP interface unit. 3463 */ 3464 static int 3465 ppp_connect_channel(struct channel *pch, int unit) 3466 { 3467 struct ppp *ppp; 3468 struct ppp_net *pn; 3469 int ret = -ENXIO; 3470 int hdrlen; 3471 3472 pn = ppp_pernet(pch->chan_net); 3473 3474 mutex_lock(&pn->all_ppp_mutex); 3475 ppp = ppp_find_unit(pn, unit); 3476 if (!ppp) 3477 goto out; 3478 write_lock_bh(&pch->upl); 3479 ret = -EINVAL; 3480 if (pch->ppp || 3481 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) 3482 goto outl; 3483 3484 ppp_lock(ppp); 3485 spin_lock_bh(&pch->downl); 3486 if (!pch->chan) { 3487 /* Don't connect unregistered channels */ 3488 spin_unlock_bh(&pch->downl); 3489 ppp_unlock(ppp); 3490 ret = -ENOTCONN; 3491 goto outl; 3492 } 3493 spin_unlock_bh(&pch->downl); 3494 if (pch->file.hdrlen > ppp->file.hdrlen) 3495 ppp->file.hdrlen = pch->file.hdrlen; 3496 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3497 if (hdrlen > ppp->dev->hard_header_len) 3498 ppp->dev->hard_header_len = hdrlen; 3499 list_add_tail(&pch->clist, &ppp->channels); 3500 ++ppp->n_channels; 3501 pch->ppp = ppp; 3502 refcount_inc(&ppp->file.refcnt); 3503 ppp_unlock(ppp); 3504 ret = 0; 3505 3506 outl: 3507 write_unlock_bh(&pch->upl); 3508 out: 3509 mutex_unlock(&pn->all_ppp_mutex); 3510 return ret; 3511 } 3512 3513 /* 3514 * Disconnect a channel from its ppp unit. 3515 */ 3516 static int 3517 ppp_disconnect_channel(struct channel *pch) 3518 { 3519 struct ppp *ppp; 3520 int err = -EINVAL; 3521 3522 write_lock_bh(&pch->upl); 3523 ppp = pch->ppp; 3524 pch->ppp = NULL; 3525 write_unlock_bh(&pch->upl); 3526 if (ppp) { 3527 /* remove it from the ppp unit's list */ 3528 ppp_lock(ppp); 3529 list_del(&pch->clist); 3530 if (--ppp->n_channels == 0) 3531 wake_up_interruptible(&ppp->file.rwait); 3532 ppp_unlock(ppp); 3533 if (refcount_dec_and_test(&ppp->file.refcnt)) 3534 ppp_destroy_interface(ppp); 3535 err = 0; 3536 } 3537 return err; 3538 } 3539 3540 /* 3541 * Free up the resources used by a ppp channel. 3542 */ 3543 static void ppp_destroy_channel(struct channel *pch) 3544 { 3545 put_net_track(pch->chan_net, &pch->ns_tracker); 3546 pch->chan_net = NULL; 3547 3548 atomic_dec(&channel_count); 3549 3550 if (!pch->file.dead) { 3551 /* "can't happen" */ 3552 pr_err("ppp: destroying undead channel %p !\n", pch); 3553 return; 3554 } 3555 skb_queue_purge(&pch->file.xq); 3556 skb_queue_purge(&pch->file.rq); 3557 kfree(pch); 3558 } 3559 3560 static void __exit ppp_cleanup(void) 3561 { 3562 /* should never happen */ 3563 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3564 pr_err("PPP: removing module but units remain!\n"); 3565 rtnl_link_unregister(&ppp_link_ops); 3566 unregister_chrdev(PPP_MAJOR, "ppp"); 3567 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3568 class_destroy(ppp_class); 3569 unregister_pernet_device(&ppp_net_ops); 3570 } 3571 3572 /* 3573 * Units handling. Caller must protect concurrent access 3574 * by holding all_ppp_mutex 3575 */ 3576 3577 /* associate pointer with specified number */ 3578 static int unit_set(struct idr *p, void *ptr, int n) 3579 { 3580 int unit; 3581 3582 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3583 if (unit == -ENOSPC) 3584 unit = -EINVAL; 3585 return unit; 3586 } 3587 3588 /* get new free unit number and associate pointer with it */ 3589 static int unit_get(struct idr *p, void *ptr, int min) 3590 { 3591 return idr_alloc(p, ptr, min, 0, GFP_KERNEL); 3592 } 3593 3594 /* put unit number back to a pool */ 3595 static void unit_put(struct idr *p, int n) 3596 { 3597 idr_remove(p, n); 3598 } 3599 3600 /* get pointer associated with the number */ 3601 static void *unit_find(struct idr *p, int n) 3602 { 3603 return idr_find(p, n); 3604 } 3605 3606 /* Module/initialization stuff */ 3607 3608 module_init(ppp_init); 3609 module_exit(ppp_cleanup); 3610 3611 EXPORT_SYMBOL(ppp_register_net_channel); 3612 EXPORT_SYMBOL(ppp_register_channel); 3613 EXPORT_SYMBOL(ppp_unregister_channel); 3614 EXPORT_SYMBOL(ppp_channel_index); 3615 EXPORT_SYMBOL(ppp_unit_number); 3616 EXPORT_SYMBOL(ppp_dev_name); 3617 EXPORT_SYMBOL(ppp_input); 3618 EXPORT_SYMBOL(ppp_input_error); 3619 EXPORT_SYMBOL(ppp_output_wakeup); 3620 EXPORT_SYMBOL(ppp_register_compressor); 3621 EXPORT_SYMBOL(ppp_unregister_compressor); 3622 MODULE_LICENSE("GPL"); 3623 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3624 MODULE_ALIAS_RTNL_LINK("ppp"); 3625 MODULE_ALIAS("devname:ppp"); 3626