2 * Generic PPP layer for Linux.
4 * Copyright 1999-2002 Paul Mackerras.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
22 * ==FILEVERSION 20041108==
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/kmod.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/idr.h>
31 #include <linux/netdevice.h>
32 #include <linux/poll.h>
33 #include <linux/ppp_defs.h>
34 #include <linux/filter.h>
35 #include <linux/ppp-ioctl.h>
36 #include <linux/ppp_channel.h>
37 #include <linux/ppp-comp.h>
38 #include <linux/skbuff.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/if_arp.h>
42 #include <linux/tcp.h>
43 #include <linux/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <linux/slab.h>
49 #include <asm/unaligned.h>
50 #include <net/slhc_vj.h>
51 #include <linux/atomic.h>
53 #include <linux/nsproxy.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
57 #define PPP_VERSION "2.4.2"
60 * Network protocols we support.
62 #define NP_IP 0 /* Internet Protocol V4 */
63 #define NP_IPV6 1 /* Internet Protocol V6 */
64 #define NP_IPX 2 /* IPX protocol */
65 #define NP_AT 3 /* Appletalk protocol */
66 #define NP_MPLS_UC 4 /* MPLS unicast */
67 #define NP_MPLS_MC 5 /* MPLS multicast */
68 #define NUM_NP 6 /* Number of NPs. */
70 #define MPHDRLEN 6 /* multilink protocol header length */
71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
74 * An instance of /dev/ppp can be associated with either a ppp
75 * interface unit or a ppp channel. In both cases, file->private_data
76 * points to one of these.
82 struct sk_buff_head xq; /* pppd transmit queue */
83 struct sk_buff_head rq; /* receive queue for pppd */
84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
86 int hdrlen; /* space to leave for headers */
87 int index; /* interface unit / channel number */
88 int dead; /* unit/channel has been shut down */
91 #define PF_TO_X(pf, X) container_of(pf, X, file)
93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
97 * Data structure to hold primary network stats for which
98 * we want to use 64 bit storage. Other network stats
99 * are stored in dev->stats of the ppp strucute.
101 struct ppp_link_stats {
109 * Data structure describing one ppp unit.
110 * A ppp unit corresponds to a ppp network interface device
111 * and represents a multilink bundle.
112 * It can have 0 or more ppp channels connected to it.
115 struct ppp_file file; /* stuff for read/write/poll 0 */
116 struct file *owner; /* file that owns this unit 48 */
117 struct list_head channels; /* list of attached channels 4c */
118 int n_channels; /* how many channels are attached 54 */
119 spinlock_t rlock; /* lock for receive side 58 */
120 spinlock_t wlock; /* lock for transmit side 5c */
121 int mru; /* max receive unit 60 */
122 unsigned int flags; /* control bits 64 */
123 unsigned int xstate; /* transmit state bits 68 */
124 unsigned int rstate; /* receive state bits 6c */
125 int debug; /* debug flags 70 */
126 struct slcompress *vj; /* state for VJ header compression */
127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
129 struct compressor *xcomp; /* transmit packet compressor 8c */
130 void *xc_state; /* its internal state 90 */
131 struct compressor *rcomp; /* receive decompressor 94 */
132 void *rc_state; /* its internal state 98 */
133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
135 struct net_device *dev; /* network interface device a4 */
136 int closing; /* is device closing down? a8 */
137 #ifdef CONFIG_PPP_MULTILINK
138 int nxchan; /* next channel to send something on */
139 u32 nxseq; /* next sequence number to send */
140 int mrru; /* MP: max reconst. receive unit */
141 u32 nextseq; /* MP: seq no of next packet */
142 u32 minseq; /* MP: min of most recent seqnos */
143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
144 #endif /* CONFIG_PPP_MULTILINK */
145 #ifdef CONFIG_PPP_FILTER
146 struct sk_filter *pass_filter; /* filter for packets to pass */
147 struct sk_filter *active_filter;/* filter for pkts to reset idle */
148 #endif /* CONFIG_PPP_FILTER */
149 struct net *ppp_net; /* the net we belong to */
150 struct ppp_link_stats stats64; /* 64 bit network stats */
154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
158 * Bits in xstate: SC_COMP_RUN
160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
165 * Private data structure for each channel.
166 * This includes the data structure used for multilink.
169 struct ppp_file file; /* stuff for read/write/poll */
170 struct list_head list; /* link in all/new_channels list */
171 struct ppp_channel *chan; /* public channel data structure */
172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
173 spinlock_t downl; /* protects `chan', file.xq dequeue */
174 struct ppp *ppp; /* ppp unit we're connected to */
175 struct net *chan_net; /* the net channel belongs to */
176 struct list_head clist; /* link in list of channels per unit */
177 rwlock_t upl; /* protects `ppp' */
178 #ifdef CONFIG_PPP_MULTILINK
179 u8 avail; /* flag used in multilink stuff */
180 u8 had_frag; /* >= 1 fragments have been sent */
181 u32 lastseq; /* MP: last sequence # received */
182 int speed; /* speed of the corresponding ppp channel*/
183 #endif /* CONFIG_PPP_MULTILINK */
187 * SMP locking issues:
188 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
189 * list and the ppp.n_channels field, you need to take both locks
190 * before you modify them.
191 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
195 static DEFINE_MUTEX(ppp_mutex);
196 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
197 static atomic_t channel_count = ATOMIC_INIT(0);
199 /* per-net private data for this module */
200 static int ppp_net_id __read_mostly;
202 /* units to ppp mapping */
203 struct idr units_idr;
206 * all_ppp_mutex protects the units_idr mapping.
207 * It also ensures that finding a ppp unit in the units_idr
208 * map and updating its file.refcnt field is atomic.
210 struct mutex all_ppp_mutex;
213 struct list_head all_channels;
214 struct list_head new_channels;
215 int last_channel_index;
218 * all_channels_lock protects all_channels and
219 * last_channel_index, and the atomicity of find
220 * a channel and updating its file.refcnt field.
222 spinlock_t all_channels_lock;
225 /* Get the PPP protocol number from a skb */
226 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
228 /* We limit the length of ppp->file.rq to this (arbitrary) value */
229 #define PPP_MAX_RQLEN 32
232 * Maximum number of multilink fragments queued up.
233 * This has to be large enough to cope with the maximum latency of
234 * the slowest channel relative to the others. Strictly it should
235 * depend on the number of channels and their characteristics.
237 #define PPP_MP_MAX_QLEN 128
239 /* Multilink header bits. */
240 #define B 0x80 /* this fragment begins a packet */
241 #define E 0x40 /* this fragment ends a packet */
243 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
244 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
245 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
248 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
249 struct file *file, unsigned int cmd, unsigned long arg);
250 static void ppp_xmit_process(struct ppp *ppp);
251 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
252 static void ppp_push(struct ppp *ppp);
253 static void ppp_channel_push(struct channel *pch);
254 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
255 struct channel *pch);
256 static void ppp_receive_error(struct ppp *ppp);
257 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
258 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
259 struct sk_buff *skb);
260 #ifdef CONFIG_PPP_MULTILINK
261 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
262 struct channel *pch);
263 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
264 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
265 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
266 #endif /* CONFIG_PPP_MULTILINK */
267 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
268 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
269 static void ppp_ccp_closed(struct ppp *ppp);
270 static struct compressor *find_compressor(int type);
271 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
272 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
273 static void init_ppp_file(struct ppp_file *pf, int kind);
274 static void ppp_shutdown_interface(struct ppp *ppp);
275 static void ppp_destroy_interface(struct ppp *ppp);
276 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
277 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
278 static int ppp_connect_channel(struct channel *pch, int unit);
279 static int ppp_disconnect_channel(struct channel *pch);
280 static void ppp_destroy_channel(struct channel *pch);
281 static int unit_get(struct idr *p, void *ptr);
282 static int unit_set(struct idr *p, void *ptr, int n);
283 static void unit_put(struct idr *p, int n);
284 static void *unit_find(struct idr *p, int n);
286 static struct class *ppp_class;
288 /* per net-namespace data */
289 static inline struct ppp_net *ppp_pernet(struct net *net)
293 return net_generic(net, ppp_net_id);
296 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
297 static inline int proto_to_npindex(int proto)
316 /* Translates an NP index into a PPP protocol number */
317 static const int npindex_to_proto[NUM_NP] = {
326 /* Translates an ethertype into an NP index */
327 static inline int ethertype_to_npindex(int ethertype)
347 /* Translates an NP index into an ethertype */
348 static const int npindex_to_ethertype[NUM_NP] = {
360 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
361 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
362 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
363 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
364 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
365 ppp_recv_lock(ppp); } while (0)
366 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
367 ppp_xmit_unlock(ppp); } while (0)
370 * /dev/ppp device routines.
371 * The /dev/ppp device is used by pppd to control the ppp unit.
372 * It supports the read, write, ioctl and poll functions.
373 * Open instances of /dev/ppp can be in one of three states:
374 * unattached, attached to a ppp unit, or attached to a ppp channel.
376 static int ppp_open(struct inode *inode, struct file *file)
379 * This could (should?) be enforced by the permissions on /dev/ppp.
381 if (!capable(CAP_NET_ADMIN))
386 static int ppp_release(struct inode *unused, struct file *file)
388 struct ppp_file *pf = file->private_data;
392 file->private_data = NULL;
393 if (pf->kind == INTERFACE) {
395 if (file == ppp->owner)
396 ppp_shutdown_interface(ppp);
398 if (atomic_dec_and_test(&pf->refcnt)) {
401 ppp_destroy_interface(PF_TO_PPP(pf));
404 ppp_destroy_channel(PF_TO_CHANNEL(pf));
412 static ssize_t ppp_read(struct file *file, char __user *buf,
413 size_t count, loff_t *ppos)
415 struct ppp_file *pf = file->private_data;
416 DECLARE_WAITQUEUE(wait, current);
418 struct sk_buff *skb = NULL;
425 add_wait_queue(&pf->rwait, &wait);
427 set_current_state(TASK_INTERRUPTIBLE);
428 skb = skb_dequeue(&pf->rq);
434 if (pf->kind == INTERFACE) {
436 * Return 0 (EOF) on an interface that has no
437 * channels connected, unless it is looping
438 * network traffic (demand mode).
440 struct ppp *ppp = PF_TO_PPP(pf);
441 if (ppp->n_channels == 0 &&
442 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
446 if (file->f_flags & O_NONBLOCK)
449 if (signal_pending(current))
453 set_current_state(TASK_RUNNING);
454 remove_wait_queue(&pf->rwait, &wait);
460 if (skb->len > count)
465 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
475 static ssize_t ppp_write(struct file *file, const char __user *buf,
476 size_t count, loff_t *ppos)
478 struct ppp_file *pf = file->private_data;
485 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
488 skb_reserve(skb, pf->hdrlen);
490 if (copy_from_user(skb_put(skb, count), buf, count)) {
495 skb_queue_tail(&pf->xq, skb);
499 ppp_xmit_process(PF_TO_PPP(pf));
502 ppp_channel_push(PF_TO_CHANNEL(pf));
512 /* No kernel lock - fine */
513 static unsigned int ppp_poll(struct file *file, poll_table *wait)
515 struct ppp_file *pf = file->private_data;
520 poll_wait(file, &pf->rwait, wait);
521 mask = POLLOUT | POLLWRNORM;
522 if (skb_peek(&pf->rq))
523 mask |= POLLIN | POLLRDNORM;
526 else if (pf->kind == INTERFACE) {
527 /* see comment in ppp_read */
528 struct ppp *ppp = PF_TO_PPP(pf);
529 if (ppp->n_channels == 0 &&
530 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
531 mask |= POLLIN | POLLRDNORM;
537 #ifdef CONFIG_PPP_FILTER
538 static int get_filter(void __user *arg, struct sock_filter **p)
540 struct sock_fprog uprog;
541 struct sock_filter *code = NULL;
544 if (copy_from_user(&uprog, arg, sizeof(uprog)))
552 len = uprog.len * sizeof(struct sock_filter);
553 code = memdup_user(uprog.filter, len);
555 return PTR_ERR(code);
560 #endif /* CONFIG_PPP_FILTER */
562 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
564 struct ppp_file *pf = file->private_data;
566 int err = -EFAULT, val, val2, i;
567 struct ppp_idle idle;
570 struct slcompress *vj;
571 void __user *argp = (void __user *)arg;
572 int __user *p = argp;
575 return ppp_unattached_ioctl(current->nsproxy->net_ns,
578 if (cmd == PPPIOCDETACH) {
580 * We have to be careful here... if the file descriptor
581 * has been dup'd, we could have another process in the
582 * middle of a poll using the same file *, so we had
583 * better not free the interface data structures -
584 * instead we fail the ioctl. Even in this case, we
585 * shut down the interface if we are the owner of it.
586 * Actually, we should get rid of PPPIOCDETACH, userland
587 * (i.e. pppd) could achieve the same effect by closing
588 * this fd and reopening /dev/ppp.
591 mutex_lock(&ppp_mutex);
592 if (pf->kind == INTERFACE) {
594 if (file == ppp->owner)
595 ppp_shutdown_interface(ppp);
597 if (atomic_long_read(&file->f_count) <= 2) {
598 ppp_release(NULL, file);
601 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
602 atomic_long_read(&file->f_count));
603 mutex_unlock(&ppp_mutex);
607 if (pf->kind == CHANNEL) {
609 struct ppp_channel *chan;
611 mutex_lock(&ppp_mutex);
612 pch = PF_TO_CHANNEL(pf);
616 if (get_user(unit, p))
618 err = ppp_connect_channel(pch, unit);
622 err = ppp_disconnect_channel(pch);
626 down_read(&pch->chan_sem);
629 if (chan && chan->ops->ioctl)
630 err = chan->ops->ioctl(chan, cmd, arg);
631 up_read(&pch->chan_sem);
633 mutex_unlock(&ppp_mutex);
637 if (pf->kind != INTERFACE) {
639 pr_err("PPP: not interface or channel??\n");
643 mutex_lock(&ppp_mutex);
647 if (get_user(val, p))
654 if (get_user(val, p))
657 cflags = ppp->flags & ~val;
658 ppp->flags = val & SC_FLAG_BITS;
660 if (cflags & SC_CCP_OPEN)
666 val = ppp->flags | ppp->xstate | ppp->rstate;
667 if (put_user(val, p))
672 case PPPIOCSCOMPRESS:
673 err = ppp_set_compress(ppp, arg);
677 if (put_user(ppp->file.index, p))
683 if (get_user(val, p))
690 if (put_user(ppp->debug, p))
696 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
697 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
698 if (copy_to_user(argp, &idle, sizeof(idle)))
704 if (get_user(val, p))
707 if ((val >> 16) != 0) {
711 vj = slhc_init(val2+1, val+1);
714 "PPP: no memory (VJ compressor)\n");
728 if (copy_from_user(&npi, argp, sizeof(npi)))
730 err = proto_to_npindex(npi.protocol);
734 if (cmd == PPPIOCGNPMODE) {
736 npi.mode = ppp->npmode[i];
737 if (copy_to_user(argp, &npi, sizeof(npi)))
740 ppp->npmode[i] = npi.mode;
741 /* we may be able to transmit more packets now (??) */
742 netif_wake_queue(ppp->dev);
747 #ifdef CONFIG_PPP_FILTER
750 struct sock_filter *code;
752 err = get_filter(argp, &code);
754 struct sock_fprog_kern fprog = {
760 if (ppp->pass_filter) {
761 sk_unattached_filter_destroy(ppp->pass_filter);
762 ppp->pass_filter = NULL;
764 if (fprog.filter != NULL)
765 err = sk_unattached_filter_create(&ppp->pass_filter,
776 struct sock_filter *code;
778 err = get_filter(argp, &code);
780 struct sock_fprog_kern fprog = {
786 if (ppp->active_filter) {
787 sk_unattached_filter_destroy(ppp->active_filter);
788 ppp->active_filter = NULL;
790 if (fprog.filter != NULL)
791 err = sk_unattached_filter_create(&ppp->active_filter,
800 #endif /* CONFIG_PPP_FILTER */
802 #ifdef CONFIG_PPP_MULTILINK
804 if (get_user(val, p))
808 ppp_recv_unlock(ppp);
811 #endif /* CONFIG_PPP_MULTILINK */
816 mutex_unlock(&ppp_mutex);
820 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
821 struct file *file, unsigned int cmd, unsigned long arg)
823 int unit, err = -EFAULT;
825 struct channel *chan;
827 int __user *p = (int __user *)arg;
829 mutex_lock(&ppp_mutex);
832 /* Create a new ppp unit */
833 if (get_user(unit, p))
835 ppp = ppp_create_interface(net, unit, &err);
838 file->private_data = &ppp->file;
841 if (put_user(ppp->file.index, p))
847 /* Attach to an existing ppp unit */
848 if (get_user(unit, p))
851 pn = ppp_pernet(net);
852 mutex_lock(&pn->all_ppp_mutex);
853 ppp = ppp_find_unit(pn, unit);
855 atomic_inc(&ppp->file.refcnt);
856 file->private_data = &ppp->file;
859 mutex_unlock(&pn->all_ppp_mutex);
863 if (get_user(unit, p))
866 pn = ppp_pernet(net);
867 spin_lock_bh(&pn->all_channels_lock);
868 chan = ppp_find_channel(pn, unit);
870 atomic_inc(&chan->file.refcnt);
871 file->private_data = &chan->file;
874 spin_unlock_bh(&pn->all_channels_lock);
880 mutex_unlock(&ppp_mutex);
884 static const struct file_operations ppp_device_fops = {
885 .owner = THIS_MODULE,
889 .unlocked_ioctl = ppp_ioctl,
891 .release = ppp_release,
892 .llseek = noop_llseek,
895 static __net_init int ppp_init_net(struct net *net)
897 struct ppp_net *pn = net_generic(net, ppp_net_id);
899 idr_init(&pn->units_idr);
900 mutex_init(&pn->all_ppp_mutex);
902 INIT_LIST_HEAD(&pn->all_channels);
903 INIT_LIST_HEAD(&pn->new_channels);
905 spin_lock_init(&pn->all_channels_lock);
910 static __net_exit void ppp_exit_net(struct net *net)
912 struct ppp_net *pn = net_generic(net, ppp_net_id);
914 idr_destroy(&pn->units_idr);
917 static struct pernet_operations ppp_net_ops = {
918 .init = ppp_init_net,
919 .exit = ppp_exit_net,
921 .size = sizeof(struct ppp_net),
924 #define PPP_MAJOR 108
926 /* Called at boot time if ppp is compiled into the kernel,
927 or at module load time (from init_module) if compiled as a module. */
928 static int __init ppp_init(void)
932 pr_info("PPP generic driver version " PPP_VERSION "\n");
934 err = register_pernet_device(&ppp_net_ops);
936 pr_err("failed to register PPP pernet device (%d)\n", err);
940 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
942 pr_err("failed to register PPP device (%d)\n", err);
946 ppp_class = class_create(THIS_MODULE, "ppp");
947 if (IS_ERR(ppp_class)) {
948 err = PTR_ERR(ppp_class);
952 /* not a big deal if we fail here :-) */
953 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
958 unregister_chrdev(PPP_MAJOR, "ppp");
960 unregister_pernet_device(&ppp_net_ops);
966 * Network interface unit routines.
969 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
971 struct ppp *ppp = netdev_priv(dev);
975 npi = ethertype_to_npindex(ntohs(skb->protocol));
979 /* Drop, accept or reject the packet */
980 switch (ppp->npmode[npi]) {
984 /* it would be nice to have a way to tell the network
985 system to queue this one up for later. */
992 /* Put the 2-byte PPP protocol number on the front,
993 making sure there is room for the address and control fields. */
994 if (skb_cow_head(skb, PPP_HDRLEN))
997 pp = skb_push(skb, 2);
998 proto = npindex_to_proto[npi];
999 put_unaligned_be16(proto, pp);
1001 skb_queue_tail(&ppp->file.xq, skb);
1002 ppp_xmit_process(ppp);
1003 return NETDEV_TX_OK;
1007 ++dev->stats.tx_dropped;
1008 return NETDEV_TX_OK;
1012 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1014 struct ppp *ppp = netdev_priv(dev);
1016 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1017 struct ppp_stats stats;
1018 struct ppp_comp_stats cstats;
1023 ppp_get_stats(ppp, &stats);
1024 if (copy_to_user(addr, &stats, sizeof(stats)))
1029 case SIOCGPPPCSTATS:
1030 memset(&cstats, 0, sizeof(cstats));
1032 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1034 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1035 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1042 if (copy_to_user(addr, vers, strlen(vers) + 1))
1054 static struct rtnl_link_stats64*
1055 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1057 struct ppp *ppp = netdev_priv(dev);
1060 stats64->rx_packets = ppp->stats64.rx_packets;
1061 stats64->rx_bytes = ppp->stats64.rx_bytes;
1062 ppp_recv_unlock(ppp);
1065 stats64->tx_packets = ppp->stats64.tx_packets;
1066 stats64->tx_bytes = ppp->stats64.tx_bytes;
1067 ppp_xmit_unlock(ppp);
1069 stats64->rx_errors = dev->stats.rx_errors;
1070 stats64->tx_errors = dev->stats.tx_errors;
1071 stats64->rx_dropped = dev->stats.rx_dropped;
1072 stats64->tx_dropped = dev->stats.tx_dropped;
1073 stats64->rx_length_errors = dev->stats.rx_length_errors;
1078 static struct lock_class_key ppp_tx_busylock;
1079 static int ppp_dev_init(struct net_device *dev)
1081 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1085 static const struct net_device_ops ppp_netdev_ops = {
1086 .ndo_init = ppp_dev_init,
1087 .ndo_start_xmit = ppp_start_xmit,
1088 .ndo_do_ioctl = ppp_net_ioctl,
1089 .ndo_get_stats64 = ppp_get_stats64,
1092 static void ppp_setup(struct net_device *dev)
1094 dev->netdev_ops = &ppp_netdev_ops;
1095 dev->hard_header_len = PPP_HDRLEN;
1098 dev->tx_queue_len = 3;
1099 dev->type = ARPHRD_PPP;
1100 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1101 dev->features |= NETIF_F_NETNS_LOCAL;
1102 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1106 * Transmit-side routines.
1110 * Called to do any work queued up on the transmit side
1111 * that can now be done.
1114 ppp_xmit_process(struct ppp *ppp)
1116 struct sk_buff *skb;
1119 if (!ppp->closing) {
1121 while (!ppp->xmit_pending &&
1122 (skb = skb_dequeue(&ppp->file.xq)))
1123 ppp_send_frame(ppp, skb);
1124 /* If there's no work left to do, tell the core net
1125 code that we can accept some more. */
1126 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1127 netif_wake_queue(ppp->dev);
1129 netif_stop_queue(ppp->dev);
1131 ppp_xmit_unlock(ppp);
1134 static inline struct sk_buff *
1135 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1137 struct sk_buff *new_skb;
1139 int new_skb_size = ppp->dev->mtu +
1140 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1141 int compressor_skb_size = ppp->dev->mtu +
1142 ppp->xcomp->comp_extra + PPP_HDRLEN;
1143 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1145 if (net_ratelimit())
1146 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1149 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1150 skb_reserve(new_skb,
1151 ppp->dev->hard_header_len - PPP_HDRLEN);
1153 /* compressor still expects A/C bytes in hdr */
1154 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1155 new_skb->data, skb->len + 2,
1156 compressor_skb_size);
1157 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1161 skb_pull(skb, 2); /* pull off A/C bytes */
1162 } else if (len == 0) {
1163 /* didn't compress, or CCP not up yet */
1164 consume_skb(new_skb);
1169 * MPPE requires that we do not send unencrypted
1170 * frames. The compressor will return -1 if we
1171 * should drop the frame. We cannot simply test
1172 * the compress_proto because MPPE and MPPC share
1175 if (net_ratelimit())
1176 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1178 consume_skb(new_skb);
1185 * Compress and send a frame.
1186 * The caller should have locked the xmit path,
1187 * and xmit_pending should be 0.
1190 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1192 int proto = PPP_PROTO(skb);
1193 struct sk_buff *new_skb;
1197 if (proto < 0x8000) {
1198 #ifdef CONFIG_PPP_FILTER
1199 /* check if we should pass this packet */
1200 /* the filter instructions are constructed assuming
1201 a four-byte PPP header on each packet */
1202 *skb_push(skb, 2) = 1;
1203 if (ppp->pass_filter &&
1204 SK_RUN_FILTER(ppp->pass_filter, skb) == 0) {
1206 netdev_printk(KERN_DEBUG, ppp->dev,
1207 "PPP: outbound frame "
1212 /* if this packet passes the active filter, record the time */
1213 if (!(ppp->active_filter &&
1214 SK_RUN_FILTER(ppp->active_filter, skb) == 0))
1215 ppp->last_xmit = jiffies;
1218 /* for data packets, record the time */
1219 ppp->last_xmit = jiffies;
1220 #endif /* CONFIG_PPP_FILTER */
1223 ++ppp->stats64.tx_packets;
1224 ppp->stats64.tx_bytes += skb->len - 2;
1228 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1230 /* try to do VJ TCP header compression */
1231 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1234 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1237 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1239 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1240 new_skb->data + 2, &cp,
1241 !(ppp->flags & SC_NO_TCP_CCID));
1242 if (cp == skb->data + 2) {
1243 /* didn't compress */
1244 consume_skb(new_skb);
1246 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1247 proto = PPP_VJC_COMP;
1248 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1250 proto = PPP_VJC_UNCOMP;
1251 cp[0] = skb->data[2];
1255 cp = skb_put(skb, len + 2);
1262 /* peek at outbound CCP frames */
1263 ppp_ccp_peek(ppp, skb, 0);
1267 /* try to do packet compression */
1268 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1269 proto != PPP_LCP && proto != PPP_CCP) {
1270 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1271 if (net_ratelimit())
1272 netdev_err(ppp->dev,
1273 "ppp: compression required but "
1274 "down - pkt dropped.\n");
1277 skb = pad_compress_skb(ppp, skb);
1283 * If we are waiting for traffic (demand dialling),
1284 * queue it up for pppd to receive.
1286 if (ppp->flags & SC_LOOP_TRAFFIC) {
1287 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1289 skb_queue_tail(&ppp->file.rq, skb);
1290 wake_up_interruptible(&ppp->file.rwait);
1294 ppp->xmit_pending = skb;
1300 ++ppp->dev->stats.tx_errors;
1304 * Try to send the frame in xmit_pending.
1305 * The caller should have the xmit path locked.
1308 ppp_push(struct ppp *ppp)
1310 struct list_head *list;
1311 struct channel *pch;
1312 struct sk_buff *skb = ppp->xmit_pending;
1317 list = &ppp->channels;
1318 if (list_empty(list)) {
1319 /* nowhere to send the packet, just drop it */
1320 ppp->xmit_pending = NULL;
1325 if ((ppp->flags & SC_MULTILINK) == 0) {
1326 /* not doing multilink: send it down the first channel */
1328 pch = list_entry(list, struct channel, clist);
1330 spin_lock_bh(&pch->downl);
1332 if (pch->chan->ops->start_xmit(pch->chan, skb))
1333 ppp->xmit_pending = NULL;
1335 /* channel got unregistered */
1337 ppp->xmit_pending = NULL;
1339 spin_unlock_bh(&pch->downl);
1343 #ifdef CONFIG_PPP_MULTILINK
1344 /* Multilink: fragment the packet over as many links
1345 as can take the packet at the moment. */
1346 if (!ppp_mp_explode(ppp, skb))
1348 #endif /* CONFIG_PPP_MULTILINK */
1350 ppp->xmit_pending = NULL;
1354 #ifdef CONFIG_PPP_MULTILINK
1355 static bool mp_protocol_compress __read_mostly = true;
1356 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1357 MODULE_PARM_DESC(mp_protocol_compress,
1358 "compress protocol id in multilink fragments");
1361 * Divide a packet to be transmitted into fragments and
1362 * send them out the individual links.
1364 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1367 int i, bits, hdrlen, mtu;
1369 int navail, nfree, nzero;
1373 unsigned char *p, *q;
1374 struct list_head *list;
1375 struct channel *pch;
1376 struct sk_buff *frag;
1377 struct ppp_channel *chan;
1379 totspeed = 0; /*total bitrate of the bundle*/
1380 nfree = 0; /* # channels which have no packet already queued */
1381 navail = 0; /* total # of usable channels (not deregistered) */
1382 nzero = 0; /* number of channels with zero speed associated*/
1383 totfree = 0; /*total # of channels available and
1384 *having no queued packets before
1385 *starting the fragmentation*/
1387 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1389 list_for_each_entry(pch, &ppp->channels, clist) {
1393 pch->speed = pch->chan->speed;
1398 if (skb_queue_empty(&pch->file.xq) ||
1400 if (pch->speed == 0)
1403 totspeed += pch->speed;
1409 if (!pch->had_frag && i < ppp->nxchan)
1415 * Don't start sending this packet unless at least half of
1416 * the channels are free. This gives much better TCP
1417 * performance if we have a lot of channels.
1419 if (nfree == 0 || nfree < navail / 2)
1420 return 0; /* can't take now, leave it in xmit_pending */
1422 /* Do protocol field compression */
1425 if (*p == 0 && mp_protocol_compress) {
1431 nbigger = len % nfree;
1433 /* skip to the channel after the one we last used
1434 and start at that one */
1435 list = &ppp->channels;
1436 for (i = 0; i < ppp->nxchan; ++i) {
1438 if (list == &ppp->channels) {
1444 /* create a fragment for each channel */
1448 if (list == &ppp->channels) {
1452 pch = list_entry(list, struct channel, clist);
1458 * Skip this channel if it has a fragment pending already and
1459 * we haven't given a fragment to all of the free channels.
1461 if (pch->avail == 1) {
1468 /* check the channel's mtu and whether it is still attached. */
1469 spin_lock_bh(&pch->downl);
1470 if (pch->chan == NULL) {
1471 /* can't use this channel, it's being deregistered */
1472 if (pch->speed == 0)
1475 totspeed -= pch->speed;
1477 spin_unlock_bh(&pch->downl);
1488 *if the channel speed is not set divide
1489 *the packet evenly among the free channels;
1490 *otherwise divide it according to the speed
1491 *of the channel we are going to transmit on
1495 if (pch->speed == 0) {
1502 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1503 ((totspeed*totfree)/pch->speed)) - hdrlen;
1505 flen += ((totfree - nzero)*pch->speed)/totspeed;
1506 nbigger -= ((totfree - nzero)*pch->speed)/
1514 *check if we are on the last channel or
1515 *we exceded the length of the data to
1518 if ((nfree <= 0) || (flen > len))
1521 *it is not worth to tx on slow channels:
1522 *in that case from the resulting flen according to the
1523 *above formula will be equal or less than zero.
1524 *Skip the channel in this case
1528 spin_unlock_bh(&pch->downl);
1533 * hdrlen includes the 2-byte PPP protocol field, but the
1534 * MTU counts only the payload excluding the protocol field.
1535 * (RFC1661 Section 2)
1537 mtu = pch->chan->mtu - (hdrlen - 2);
1544 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1547 q = skb_put(frag, flen + hdrlen);
1549 /* make the MP header */
1550 put_unaligned_be16(PPP_MP, q);
1551 if (ppp->flags & SC_MP_XSHORTSEQ) {
1552 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1556 q[3] = ppp->nxseq >> 16;
1557 q[4] = ppp->nxseq >> 8;
1561 memcpy(q + hdrlen, p, flen);
1563 /* try to send it down the channel */
1565 if (!skb_queue_empty(&pch->file.xq) ||
1566 !chan->ops->start_xmit(chan, frag))
1567 skb_queue_tail(&pch->file.xq, frag);
1573 spin_unlock_bh(&pch->downl);
1580 spin_unlock_bh(&pch->downl);
1582 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1583 ++ppp->dev->stats.tx_errors;
1585 return 1; /* abandon the frame */
1587 #endif /* CONFIG_PPP_MULTILINK */
1590 * Try to send data out on a channel.
1593 ppp_channel_push(struct channel *pch)
1595 struct sk_buff *skb;
1598 spin_lock_bh(&pch->downl);
1600 while (!skb_queue_empty(&pch->file.xq)) {
1601 skb = skb_dequeue(&pch->file.xq);
1602 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1603 /* put the packet back and try again later */
1604 skb_queue_head(&pch->file.xq, skb);
1609 /* channel got deregistered */
1610 skb_queue_purge(&pch->file.xq);
1612 spin_unlock_bh(&pch->downl);
1613 /* see if there is anything from the attached unit to be sent */
1614 if (skb_queue_empty(&pch->file.xq)) {
1615 read_lock_bh(&pch->upl);
1618 ppp_xmit_process(ppp);
1619 read_unlock_bh(&pch->upl);
1624 * Receive-side routines.
1627 struct ppp_mp_skb_parm {
1631 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1634 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1638 ppp_receive_frame(ppp, skb, pch);
1641 ppp_recv_unlock(ppp);
1645 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1647 struct channel *pch = chan->ppp;
1655 read_lock_bh(&pch->upl);
1656 if (!pskb_may_pull(skb, 2)) {
1659 ++pch->ppp->dev->stats.rx_length_errors;
1660 ppp_receive_error(pch->ppp);
1665 proto = PPP_PROTO(skb);
1666 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1667 /* put it on the channel queue */
1668 skb_queue_tail(&pch->file.rq, skb);
1669 /* drop old frames if queue too long */
1670 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1671 (skb = skb_dequeue(&pch->file.rq)))
1673 wake_up_interruptible(&pch->file.rwait);
1675 ppp_do_recv(pch->ppp, skb, pch);
1679 read_unlock_bh(&pch->upl);
1682 /* Put a 0-length skb in the receive queue as an error indication */
1684 ppp_input_error(struct ppp_channel *chan, int code)
1686 struct channel *pch = chan->ppp;
1687 struct sk_buff *skb;
1692 read_lock_bh(&pch->upl);
1694 skb = alloc_skb(0, GFP_ATOMIC);
1696 skb->len = 0; /* probably unnecessary */
1698 ppp_do_recv(pch->ppp, skb, pch);
1701 read_unlock_bh(&pch->upl);
1705 * We come in here to process a received frame.
1706 * The receive side of the ppp unit is locked.
1709 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1711 /* note: a 0-length skb is used as an error indication */
1713 #ifdef CONFIG_PPP_MULTILINK
1714 /* XXX do channel-level decompression here */
1715 if (PPP_PROTO(skb) == PPP_MP)
1716 ppp_receive_mp_frame(ppp, skb, pch);
1718 #endif /* CONFIG_PPP_MULTILINK */
1719 ppp_receive_nonmp_frame(ppp, skb);
1722 ppp_receive_error(ppp);
1727 ppp_receive_error(struct ppp *ppp)
1729 ++ppp->dev->stats.rx_errors;
1735 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1738 int proto, len, npi;
1741 * Decompress the frame, if compressed.
1742 * Note that some decompressors need to see uncompressed frames
1743 * that come in as well as compressed frames.
1745 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1746 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1747 skb = ppp_decompress_frame(ppp, skb);
1749 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1752 proto = PPP_PROTO(skb);
1755 /* decompress VJ compressed packets */
1756 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1759 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1760 /* copy to a new sk_buff with more tailroom */
1761 ns = dev_alloc_skb(skb->len + 128);
1763 netdev_err(ppp->dev, "PPP: no memory "
1768 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1773 skb->ip_summed = CHECKSUM_NONE;
1775 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1777 netdev_printk(KERN_DEBUG, ppp->dev,
1778 "PPP: VJ decompression error\n");
1783 skb_put(skb, len - skb->len);
1784 else if (len < skb->len)
1789 case PPP_VJC_UNCOMP:
1790 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1793 /* Until we fix the decompressor need to make sure
1794 * data portion is linear.
1796 if (!pskb_may_pull(skb, skb->len))
1799 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1800 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1807 ppp_ccp_peek(ppp, skb, 1);
1811 ++ppp->stats64.rx_packets;
1812 ppp->stats64.rx_bytes += skb->len - 2;
1814 npi = proto_to_npindex(proto);
1816 /* control or unknown frame - pass it to pppd */
1817 skb_queue_tail(&ppp->file.rq, skb);
1818 /* limit queue length by dropping old frames */
1819 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1820 (skb = skb_dequeue(&ppp->file.rq)))
1822 /* wake up any process polling or blocking on read */
1823 wake_up_interruptible(&ppp->file.rwait);
1826 /* network protocol frame - give it to the kernel */
1828 #ifdef CONFIG_PPP_FILTER
1829 /* check if the packet passes the pass and active filters */
1830 /* the filter instructions are constructed assuming
1831 a four-byte PPP header on each packet */
1832 if (ppp->pass_filter || ppp->active_filter) {
1833 if (skb_unclone(skb, GFP_ATOMIC))
1836 *skb_push(skb, 2) = 0;
1837 if (ppp->pass_filter &&
1838 SK_RUN_FILTER(ppp->pass_filter, skb) == 0) {
1840 netdev_printk(KERN_DEBUG, ppp->dev,
1841 "PPP: inbound frame "
1846 if (!(ppp->active_filter &&
1847 SK_RUN_FILTER(ppp->active_filter, skb) == 0))
1848 ppp->last_recv = jiffies;
1851 #endif /* CONFIG_PPP_FILTER */
1852 ppp->last_recv = jiffies;
1854 if ((ppp->dev->flags & IFF_UP) == 0 ||
1855 ppp->npmode[npi] != NPMODE_PASS) {
1858 /* chop off protocol */
1859 skb_pull_rcsum(skb, 2);
1860 skb->dev = ppp->dev;
1861 skb->protocol = htons(npindex_to_ethertype[npi]);
1862 skb_reset_mac_header(skb);
1870 ppp_receive_error(ppp);
1873 static struct sk_buff *
1874 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1876 int proto = PPP_PROTO(skb);
1880 /* Until we fix all the decompressor's need to make sure
1881 * data portion is linear.
1883 if (!pskb_may_pull(skb, skb->len))
1886 if (proto == PPP_COMP) {
1889 switch(ppp->rcomp->compress_proto) {
1891 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1894 obuff_size = ppp->mru + PPP_HDRLEN;
1898 ns = dev_alloc_skb(obuff_size);
1900 netdev_err(ppp->dev, "ppp_decompress_frame: "
1904 /* the decompressor still expects the A/C bytes in the hdr */
1905 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1906 skb->len + 2, ns->data, obuff_size);
1908 /* Pass the compressed frame to pppd as an
1909 error indication. */
1910 if (len == DECOMP_FATALERROR)
1911 ppp->rstate |= SC_DC_FERROR;
1919 skb_pull(skb, 2); /* pull off the A/C bytes */
1922 /* Uncompressed frame - pass to decompressor so it
1923 can update its dictionary if necessary. */
1924 if (ppp->rcomp->incomp)
1925 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1932 ppp->rstate |= SC_DC_ERROR;
1933 ppp_receive_error(ppp);
1937 #ifdef CONFIG_PPP_MULTILINK
1939 * Receive a multilink frame.
1940 * We put it on the reconstruction queue and then pull off
1941 * as many completed frames as we can.
1944 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1948 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1950 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1951 goto err; /* no good, throw it away */
1953 /* Decode sequence number and begin/end bits */
1954 if (ppp->flags & SC_MP_SHORTSEQ) {
1955 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1958 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1961 PPP_MP_CB(skb)->BEbits = skb->data[2];
1962 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1965 * Do protocol ID decompression on the first fragment of each packet.
1967 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1968 *skb_push(skb, 1) = 0;
1971 * Expand sequence number to 32 bits, making it as close
1972 * as possible to ppp->minseq.
1974 seq |= ppp->minseq & ~mask;
1975 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1977 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1978 seq -= mask + 1; /* should never happen */
1979 PPP_MP_CB(skb)->sequence = seq;
1983 * If this packet comes before the next one we were expecting,
1986 if (seq_before(seq, ppp->nextseq)) {
1988 ++ppp->dev->stats.rx_dropped;
1989 ppp_receive_error(ppp);
1994 * Reevaluate minseq, the minimum over all channels of the
1995 * last sequence number received on each channel. Because of
1996 * the increasing sequence number rule, we know that any fragment
1997 * before `minseq' which hasn't arrived is never going to arrive.
1998 * The list of channels can't change because we have the receive
1999 * side of the ppp unit locked.
2001 list_for_each_entry(ch, &ppp->channels, clist) {
2002 if (seq_before(ch->lastseq, seq))
2005 if (seq_before(ppp->minseq, seq))
2008 /* Put the fragment on the reconstruction queue */
2009 ppp_mp_insert(ppp, skb);
2011 /* If the queue is getting long, don't wait any longer for packets
2012 before the start of the queue. */
2013 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2014 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2015 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2016 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2019 /* Pull completed packets off the queue and receive them. */
2020 while ((skb = ppp_mp_reconstruct(ppp))) {
2021 if (pskb_may_pull(skb, 2))
2022 ppp_receive_nonmp_frame(ppp, skb);
2024 ++ppp->dev->stats.rx_length_errors;
2026 ppp_receive_error(ppp);
2034 ppp_receive_error(ppp);
2038 * Insert a fragment on the MP reconstruction queue.
2039 * The queue is ordered by increasing sequence number.
2042 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2045 struct sk_buff_head *list = &ppp->mrq;
2046 u32 seq = PPP_MP_CB(skb)->sequence;
2048 /* N.B. we don't need to lock the list lock because we have the
2049 ppp unit receive-side lock. */
2050 skb_queue_walk(list, p) {
2051 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2054 __skb_queue_before(list, p, skb);
2058 * Reconstruct a packet from the MP fragment queue.
2059 * We go through increasing sequence numbers until we find a
2060 * complete packet, or we get to the sequence number for a fragment
2061 * which hasn't arrived but might still do so.
2063 static struct sk_buff *
2064 ppp_mp_reconstruct(struct ppp *ppp)
2066 u32 seq = ppp->nextseq;
2067 u32 minseq = ppp->minseq;
2068 struct sk_buff_head *list = &ppp->mrq;
2069 struct sk_buff *p, *tmp;
2070 struct sk_buff *head, *tail;
2071 struct sk_buff *skb = NULL;
2072 int lost = 0, len = 0;
2074 if (ppp->mrru == 0) /* do nothing until mrru is set */
2078 skb_queue_walk_safe(list, p, tmp) {
2080 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2081 /* this can't happen, anyway ignore the skb */
2082 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2084 PPP_MP_CB(p)->sequence, seq);
2085 __skb_unlink(p, list);
2089 if (PPP_MP_CB(p)->sequence != seq) {
2091 /* Fragment `seq' is missing. If it is after
2092 minseq, it might arrive later, so stop here. */
2093 if (seq_after(seq, minseq))
2095 /* Fragment `seq' is lost, keep going. */
2098 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2099 minseq + 1: PPP_MP_CB(p)->sequence;
2102 netdev_printk(KERN_DEBUG, ppp->dev,
2103 "lost frag %u..%u\n",
2110 * At this point we know that all the fragments from
2111 * ppp->nextseq to seq are either present or lost.
2112 * Also, there are no complete packets in the queue
2113 * that have no missing fragments and end before this
2117 /* B bit set indicates this fragment starts a packet */
2118 if (PPP_MP_CB(p)->BEbits & B) {
2126 /* Got a complete packet yet? */
2127 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2128 (PPP_MP_CB(head)->BEbits & B)) {
2129 if (len > ppp->mrru + 2) {
2130 ++ppp->dev->stats.rx_length_errors;
2131 netdev_printk(KERN_DEBUG, ppp->dev,
2132 "PPP: reconstructed packet"
2133 " is too long (%d)\n", len);
2138 ppp->nextseq = seq + 1;
2142 * If this is the ending fragment of a packet,
2143 * and we haven't found a complete valid packet yet,
2144 * we can discard up to and including this fragment.
2146 if (PPP_MP_CB(p)->BEbits & E) {
2147 struct sk_buff *tmp2;
2149 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2151 netdev_printk(KERN_DEBUG, ppp->dev,
2152 "discarding frag %u\n",
2153 PPP_MP_CB(p)->sequence);
2154 __skb_unlink(p, list);
2157 head = skb_peek(list);
2164 /* If we have a complete packet, copy it all into one skb. */
2166 /* If we have discarded any fragments,
2167 signal a receive error. */
2168 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2169 skb_queue_walk_safe(list, p, tmp) {
2173 netdev_printk(KERN_DEBUG, ppp->dev,
2174 "discarding frag %u\n",
2175 PPP_MP_CB(p)->sequence);
2176 __skb_unlink(p, list);
2181 netdev_printk(KERN_DEBUG, ppp->dev,
2182 " missed pkts %u..%u\n",
2184 PPP_MP_CB(head)->sequence-1);
2185 ++ppp->dev->stats.rx_dropped;
2186 ppp_receive_error(ppp);
2191 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2192 p = skb_queue_next(list, head);
2193 __skb_unlink(skb, list);
2194 skb_queue_walk_from_safe(list, p, tmp) {
2195 __skb_unlink(p, list);
2201 skb->data_len += p->len;
2202 skb->truesize += p->truesize;
2208 __skb_unlink(skb, list);
2211 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2216 #endif /* CONFIG_PPP_MULTILINK */
2219 * Channel interface.
2222 /* Create a new, unattached ppp channel. */
2223 int ppp_register_channel(struct ppp_channel *chan)
2225 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2228 /* Create a new, unattached ppp channel for specified net. */
2229 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2231 struct channel *pch;
2234 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2238 pn = ppp_pernet(net);
2242 pch->chan_net = net;
2244 init_ppp_file(&pch->file, CHANNEL);
2245 pch->file.hdrlen = chan->hdrlen;
2246 #ifdef CONFIG_PPP_MULTILINK
2248 #endif /* CONFIG_PPP_MULTILINK */
2249 init_rwsem(&pch->chan_sem);
2250 spin_lock_init(&pch->downl);
2251 rwlock_init(&pch->upl);
2253 spin_lock_bh(&pn->all_channels_lock);
2254 pch->file.index = ++pn->last_channel_index;
2255 list_add(&pch->list, &pn->new_channels);
2256 atomic_inc(&channel_count);
2257 spin_unlock_bh(&pn->all_channels_lock);
2263 * Return the index of a channel.
2265 int ppp_channel_index(struct ppp_channel *chan)
2267 struct channel *pch = chan->ppp;
2270 return pch->file.index;
2275 * Return the PPP unit number to which a channel is connected.
2277 int ppp_unit_number(struct ppp_channel *chan)
2279 struct channel *pch = chan->ppp;
2283 read_lock_bh(&pch->upl);
2285 unit = pch->ppp->file.index;
2286 read_unlock_bh(&pch->upl);
2292 * Return the PPP device interface name of a channel.
2294 char *ppp_dev_name(struct ppp_channel *chan)
2296 struct channel *pch = chan->ppp;
2300 read_lock_bh(&pch->upl);
2301 if (pch->ppp && pch->ppp->dev)
2302 name = pch->ppp->dev->name;
2303 read_unlock_bh(&pch->upl);
2310 * Disconnect a channel from the generic layer.
2311 * This must be called in process context.
2314 ppp_unregister_channel(struct ppp_channel *chan)
2316 struct channel *pch = chan->ppp;
2320 return; /* should never happen */
2325 * This ensures that we have returned from any calls into the
2326 * the channel's start_xmit or ioctl routine before we proceed.
2328 down_write(&pch->chan_sem);
2329 spin_lock_bh(&pch->downl);
2331 spin_unlock_bh(&pch->downl);
2332 up_write(&pch->chan_sem);
2333 ppp_disconnect_channel(pch);
2335 pn = ppp_pernet(pch->chan_net);
2336 spin_lock_bh(&pn->all_channels_lock);
2337 list_del(&pch->list);
2338 spin_unlock_bh(&pn->all_channels_lock);
2341 wake_up_interruptible(&pch->file.rwait);
2342 if (atomic_dec_and_test(&pch->file.refcnt))
2343 ppp_destroy_channel(pch);
2347 * Callback from a channel when it can accept more to transmit.
2348 * This should be called at BH/softirq level, not interrupt level.
2351 ppp_output_wakeup(struct ppp_channel *chan)
2353 struct channel *pch = chan->ppp;
2357 ppp_channel_push(pch);
2361 * Compression control.
2364 /* Process the PPPIOCSCOMPRESS ioctl. */
2366 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2369 struct compressor *cp, *ocomp;
2370 struct ppp_option_data data;
2371 void *state, *ostate;
2372 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2375 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2376 (data.length <= CCP_MAX_OPTION_LENGTH &&
2377 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2380 if (data.length > CCP_MAX_OPTION_LENGTH ||
2381 ccp_option[1] < 2 || ccp_option[1] > data.length)
2384 cp = try_then_request_module(
2385 find_compressor(ccp_option[0]),
2386 "ppp-compress-%d", ccp_option[0]);
2391 if (data.transmit) {
2392 state = cp->comp_alloc(ccp_option, data.length);
2395 ppp->xstate &= ~SC_COMP_RUN;
2397 ostate = ppp->xc_state;
2399 ppp->xc_state = state;
2400 ppp_xmit_unlock(ppp);
2402 ocomp->comp_free(ostate);
2403 module_put(ocomp->owner);
2407 module_put(cp->owner);
2410 state = cp->decomp_alloc(ccp_option, data.length);
2413 ppp->rstate &= ~SC_DECOMP_RUN;
2415 ostate = ppp->rc_state;
2417 ppp->rc_state = state;
2418 ppp_recv_unlock(ppp);
2420 ocomp->decomp_free(ostate);
2421 module_put(ocomp->owner);
2425 module_put(cp->owner);
2433 * Look at a CCP packet and update our state accordingly.
2434 * We assume the caller has the xmit or recv path locked.
2437 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2442 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2443 return; /* no header */
2446 switch (CCP_CODE(dp)) {
2449 /* A ConfReq starts negotiation of compression
2450 * in one direction of transmission,
2451 * and hence brings it down...but which way?
2454 * A ConfReq indicates what the sender would like to receive
2457 /* He is proposing what I should send */
2458 ppp->xstate &= ~SC_COMP_RUN;
2460 /* I am proposing to what he should send */
2461 ppp->rstate &= ~SC_DECOMP_RUN;
2468 * CCP is going down, both directions of transmission
2470 ppp->rstate &= ~SC_DECOMP_RUN;
2471 ppp->xstate &= ~SC_COMP_RUN;
2475 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2477 len = CCP_LENGTH(dp);
2478 if (!pskb_may_pull(skb, len + 2))
2479 return; /* too short */
2482 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2485 /* we will start receiving compressed packets */
2488 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2489 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2490 ppp->rstate |= SC_DECOMP_RUN;
2491 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2494 /* we will soon start sending compressed packets */
2497 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2498 ppp->file.index, 0, ppp->debug))
2499 ppp->xstate |= SC_COMP_RUN;
2504 /* reset the [de]compressor */
2505 if ((ppp->flags & SC_CCP_UP) == 0)
2508 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2509 ppp->rcomp->decomp_reset(ppp->rc_state);
2510 ppp->rstate &= ~SC_DC_ERROR;
2513 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2514 ppp->xcomp->comp_reset(ppp->xc_state);
2520 /* Free up compression resources. */
2522 ppp_ccp_closed(struct ppp *ppp)
2524 void *xstate, *rstate;
2525 struct compressor *xcomp, *rcomp;
2528 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2531 xstate = ppp->xc_state;
2532 ppp->xc_state = NULL;
2535 rstate = ppp->rc_state;
2536 ppp->rc_state = NULL;
2540 xcomp->comp_free(xstate);
2541 module_put(xcomp->owner);
2544 rcomp->decomp_free(rstate);
2545 module_put(rcomp->owner);
2549 /* List of compressors. */
2550 static LIST_HEAD(compressor_list);
2551 static DEFINE_SPINLOCK(compressor_list_lock);
2553 struct compressor_entry {
2554 struct list_head list;
2555 struct compressor *comp;
2558 static struct compressor_entry *
2559 find_comp_entry(int proto)
2561 struct compressor_entry *ce;
2563 list_for_each_entry(ce, &compressor_list, list) {
2564 if (ce->comp->compress_proto == proto)
2570 /* Register a compressor */
2572 ppp_register_compressor(struct compressor *cp)
2574 struct compressor_entry *ce;
2576 spin_lock(&compressor_list_lock);
2578 if (find_comp_entry(cp->compress_proto))
2581 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2586 list_add(&ce->list, &compressor_list);
2588 spin_unlock(&compressor_list_lock);
2592 /* Unregister a compressor */
2594 ppp_unregister_compressor(struct compressor *cp)
2596 struct compressor_entry *ce;
2598 spin_lock(&compressor_list_lock);
2599 ce = find_comp_entry(cp->compress_proto);
2600 if (ce && ce->comp == cp) {
2601 list_del(&ce->list);
2604 spin_unlock(&compressor_list_lock);
2607 /* Find a compressor. */
2608 static struct compressor *
2609 find_compressor(int type)
2611 struct compressor_entry *ce;
2612 struct compressor *cp = NULL;
2614 spin_lock(&compressor_list_lock);
2615 ce = find_comp_entry(type);
2618 if (!try_module_get(cp->owner))
2621 spin_unlock(&compressor_list_lock);
2626 * Miscelleneous stuff.
2630 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2632 struct slcompress *vj = ppp->vj;
2634 memset(st, 0, sizeof(*st));
2635 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2636 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2637 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2638 st->p.ppp_opackets = ppp->stats64.tx_packets;
2639 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2640 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2643 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2644 st->vj.vjs_compressed = vj->sls_o_compressed;
2645 st->vj.vjs_searches = vj->sls_o_searches;
2646 st->vj.vjs_misses = vj->sls_o_misses;
2647 st->vj.vjs_errorin = vj->sls_i_error;
2648 st->vj.vjs_tossed = vj->sls_i_tossed;
2649 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2650 st->vj.vjs_compressedin = vj->sls_i_compressed;
2654 * Stuff for handling the lists of ppp units and channels
2655 * and for initialization.
2659 * Create a new ppp interface unit. Fails if it can't allocate memory
2660 * or if there is already a unit with the requested number.
2661 * unit == -1 means allocate a new number.
2664 ppp_create_interface(struct net *net, int unit, int *retp)
2668 struct net_device *dev = NULL;
2672 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2676 pn = ppp_pernet(net);
2678 ppp = netdev_priv(dev);
2681 init_ppp_file(&ppp->file, INTERFACE);
2682 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2683 for (i = 0; i < NUM_NP; ++i)
2684 ppp->npmode[i] = NPMODE_PASS;
2685 INIT_LIST_HEAD(&ppp->channels);
2686 spin_lock_init(&ppp->rlock);
2687 spin_lock_init(&ppp->wlock);
2688 #ifdef CONFIG_PPP_MULTILINK
2690 skb_queue_head_init(&ppp->mrq);
2691 #endif /* CONFIG_PPP_MULTILINK */
2692 #ifdef CONFIG_PPP_FILTER
2693 ppp->pass_filter = NULL;
2694 ppp->active_filter = NULL;
2695 #endif /* CONFIG_PPP_FILTER */
2698 * drum roll: don't forget to set
2699 * the net device is belong to
2701 dev_net_set(dev, net);
2703 mutex_lock(&pn->all_ppp_mutex);
2706 unit = unit_get(&pn->units_idr, ppp);
2713 if (unit_find(&pn->units_idr, unit))
2714 goto out2; /* unit already exists */
2716 * if caller need a specified unit number
2717 * lets try to satisfy him, otherwise --
2718 * he should better ask us for new unit number
2720 * NOTE: yes I know that returning EEXIST it's not
2721 * fair but at least pppd will ask us to allocate
2722 * new unit in this case so user is happy :)
2724 unit = unit_set(&pn->units_idr, ppp, unit);
2729 /* Initialize the new ppp unit */
2730 ppp->file.index = unit;
2731 sprintf(dev->name, "ppp%d", unit);
2733 ret = register_netdev(dev);
2735 unit_put(&pn->units_idr, unit);
2736 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2743 atomic_inc(&ppp_unit_count);
2744 mutex_unlock(&pn->all_ppp_mutex);
2750 mutex_unlock(&pn->all_ppp_mutex);
2758 * Initialize a ppp_file structure.
2761 init_ppp_file(struct ppp_file *pf, int kind)
2764 skb_queue_head_init(&pf->xq);
2765 skb_queue_head_init(&pf->rq);
2766 atomic_set(&pf->refcnt, 1);
2767 init_waitqueue_head(&pf->rwait);
2771 * Take down a ppp interface unit - called when the owning file
2772 * (the one that created the unit) is closed or detached.
2774 static void ppp_shutdown_interface(struct ppp *ppp)
2778 pn = ppp_pernet(ppp->ppp_net);
2779 mutex_lock(&pn->all_ppp_mutex);
2781 /* This will call dev_close() for us. */
2783 if (!ppp->closing) {
2786 unregister_netdev(ppp->dev);
2787 unit_put(&pn->units_idr, ppp->file.index);
2793 wake_up_interruptible(&ppp->file.rwait);
2795 mutex_unlock(&pn->all_ppp_mutex);
2799 * Free the memory used by a ppp unit. This is only called once
2800 * there are no channels connected to the unit and no file structs
2801 * that reference the unit.
2803 static void ppp_destroy_interface(struct ppp *ppp)
2805 atomic_dec(&ppp_unit_count);
2807 if (!ppp->file.dead || ppp->n_channels) {
2808 /* "can't happen" */
2809 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2810 "but dead=%d n_channels=%d !\n",
2811 ppp, ppp->file.dead, ppp->n_channels);
2815 ppp_ccp_closed(ppp);
2820 skb_queue_purge(&ppp->file.xq);
2821 skb_queue_purge(&ppp->file.rq);
2822 #ifdef CONFIG_PPP_MULTILINK
2823 skb_queue_purge(&ppp->mrq);
2824 #endif /* CONFIG_PPP_MULTILINK */
2825 #ifdef CONFIG_PPP_FILTER
2826 if (ppp->pass_filter) {
2827 sk_unattached_filter_destroy(ppp->pass_filter);
2828 ppp->pass_filter = NULL;
2831 if (ppp->active_filter) {
2832 sk_unattached_filter_destroy(ppp->active_filter);
2833 ppp->active_filter = NULL;
2835 #endif /* CONFIG_PPP_FILTER */
2837 kfree_skb(ppp->xmit_pending);
2839 free_netdev(ppp->dev);
2843 * Locate an existing ppp unit.
2844 * The caller should have locked the all_ppp_mutex.
2847 ppp_find_unit(struct ppp_net *pn, int unit)
2849 return unit_find(&pn->units_idr, unit);
2853 * Locate an existing ppp channel.
2854 * The caller should have locked the all_channels_lock.
2855 * First we look in the new_channels list, then in the
2856 * all_channels list. If found in the new_channels list,
2857 * we move it to the all_channels list. This is for speed
2858 * when we have a lot of channels in use.
2860 static struct channel *
2861 ppp_find_channel(struct ppp_net *pn, int unit)
2863 struct channel *pch;
2865 list_for_each_entry(pch, &pn->new_channels, list) {
2866 if (pch->file.index == unit) {
2867 list_move(&pch->list, &pn->all_channels);
2872 list_for_each_entry(pch, &pn->all_channels, list) {
2873 if (pch->file.index == unit)
2881 * Connect a PPP channel to a PPP interface unit.
2884 ppp_connect_channel(struct channel *pch, int unit)
2891 pn = ppp_pernet(pch->chan_net);
2893 mutex_lock(&pn->all_ppp_mutex);
2894 ppp = ppp_find_unit(pn, unit);
2897 write_lock_bh(&pch->upl);
2903 if (pch->file.hdrlen > ppp->file.hdrlen)
2904 ppp->file.hdrlen = pch->file.hdrlen;
2905 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2906 if (hdrlen > ppp->dev->hard_header_len)
2907 ppp->dev->hard_header_len = hdrlen;
2908 list_add_tail(&pch->clist, &ppp->channels);
2911 atomic_inc(&ppp->file.refcnt);
2916 write_unlock_bh(&pch->upl);
2918 mutex_unlock(&pn->all_ppp_mutex);
2923 * Disconnect a channel from its ppp unit.
2926 ppp_disconnect_channel(struct channel *pch)
2931 write_lock_bh(&pch->upl);
2934 write_unlock_bh(&pch->upl);
2936 /* remove it from the ppp unit's list */
2938 list_del(&pch->clist);
2939 if (--ppp->n_channels == 0)
2940 wake_up_interruptible(&ppp->file.rwait);
2942 if (atomic_dec_and_test(&ppp->file.refcnt))
2943 ppp_destroy_interface(ppp);
2950 * Free up the resources used by a ppp channel.
2952 static void ppp_destroy_channel(struct channel *pch)
2954 atomic_dec(&channel_count);
2956 if (!pch->file.dead) {
2957 /* "can't happen" */
2958 pr_err("ppp: destroying undead channel %p !\n", pch);
2961 skb_queue_purge(&pch->file.xq);
2962 skb_queue_purge(&pch->file.rq);
2966 static void __exit ppp_cleanup(void)
2968 /* should never happen */
2969 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2970 pr_err("PPP: removing module but units remain!\n");
2971 unregister_chrdev(PPP_MAJOR, "ppp");
2972 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2973 class_destroy(ppp_class);
2974 unregister_pernet_device(&ppp_net_ops);
2978 * Units handling. Caller must protect concurrent access
2979 * by holding all_ppp_mutex
2982 /* associate pointer with specified number */
2983 static int unit_set(struct idr *p, void *ptr, int n)
2987 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
2988 if (unit == -ENOSPC)
2993 /* get new free unit number and associate pointer with it */
2994 static int unit_get(struct idr *p, void *ptr)
2996 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
2999 /* put unit number back to a pool */
3000 static void unit_put(struct idr *p, int n)
3005 /* get pointer associated with the number */
3006 static void *unit_find(struct idr *p, int n)
3008 return idr_find(p, n);
3011 /* Module/initialization stuff */
3013 module_init(ppp_init);
3014 module_exit(ppp_cleanup);
3016 EXPORT_SYMBOL(ppp_register_net_channel);
3017 EXPORT_SYMBOL(ppp_register_channel);
3018 EXPORT_SYMBOL(ppp_unregister_channel);
3019 EXPORT_SYMBOL(ppp_channel_index);
3020 EXPORT_SYMBOL(ppp_unit_number);
3021 EXPORT_SYMBOL(ppp_dev_name);
3022 EXPORT_SYMBOL(ppp_input);
3023 EXPORT_SYMBOL(ppp_input_error);
3024 EXPORT_SYMBOL(ppp_output_wakeup);
3025 EXPORT_SYMBOL(ppp_register_compressor);
3026 EXPORT_SYMBOL(ppp_unregister_compressor);
3027 MODULE_LICENSE("GPL");
3028 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3029 MODULE_ALIAS("devname:ppp");