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/if_ppp.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 <net/slhc_vj.h>
50 #include <asm/atomic.h>
52 #include <linux/nsproxy.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
56 #define PPP_VERSION "2.4.2"
59 * Network protocols we support.
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. */
69 #define MPHDRLEN 6 /* multilink protocol header length */
70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
73 * An instance of /dev/ppp can be associated with either a ppp
74 * interface unit or a ppp channel. In both cases, file->private_data
75 * points to one of these.
81 struct sk_buff_head xq; /* pppd transmit queue */
82 struct sk_buff_head rq; /* receive queue for pppd */
83 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
84 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
85 int hdrlen; /* space to leave for headers */
86 int index; /* interface unit / channel number */
87 int dead; /* unit/channel has been shut down */
90 #define PF_TO_X(pf, X) container_of(pf, X, file)
92 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
93 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
96 * Data structure describing one ppp unit.
97 * A ppp unit corresponds to a ppp network interface device
98 * and represents a multilink bundle.
99 * It can have 0 or more ppp channels connected to it.
102 struct ppp_file file; /* stuff for read/write/poll 0 */
103 struct file *owner; /* file that owns this unit 48 */
104 struct list_head channels; /* list of attached channels 4c */
105 int n_channels; /* how many channels are attached 54 */
106 spinlock_t rlock; /* lock for receive side 58 */
107 spinlock_t wlock; /* lock for transmit side 5c */
108 int mru; /* max receive unit 60 */
109 unsigned int flags; /* control bits 64 */
110 unsigned int xstate; /* transmit state bits 68 */
111 unsigned int rstate; /* receive state bits 6c */
112 int debug; /* debug flags 70 */
113 struct slcompress *vj; /* state for VJ header compression */
114 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
115 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
116 struct compressor *xcomp; /* transmit packet compressor 8c */
117 void *xc_state; /* its internal state 90 */
118 struct compressor *rcomp; /* receive decompressor 94 */
119 void *rc_state; /* its internal state 98 */
120 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
121 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
122 struct net_device *dev; /* network interface device a4 */
123 int closing; /* is device closing down? a8 */
124 #ifdef CONFIG_PPP_MULTILINK
125 int nxchan; /* next channel to send something on */
126 u32 nxseq; /* next sequence number to send */
127 int mrru; /* MP: max reconst. receive unit */
128 u32 nextseq; /* MP: seq no of next packet */
129 u32 minseq; /* MP: min of most recent seqnos */
130 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
131 #endif /* CONFIG_PPP_MULTILINK */
132 #ifdef CONFIG_PPP_FILTER
133 struct sock_filter *pass_filter; /* filter for packets to pass */
134 struct sock_filter *active_filter;/* filter for pkts to reset idle */
135 unsigned pass_len, active_len;
136 #endif /* CONFIG_PPP_FILTER */
137 struct net *ppp_net; /* the net we belong to */
141 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
142 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
144 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
145 * Bits in xstate: SC_COMP_RUN
147 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
148 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
149 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
152 * Private data structure for each channel.
153 * This includes the data structure used for multilink.
156 struct ppp_file file; /* stuff for read/write/poll */
157 struct list_head list; /* link in all/new_channels list */
158 struct ppp_channel *chan; /* public channel data structure */
159 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
160 spinlock_t downl; /* protects `chan', file.xq dequeue */
161 struct ppp *ppp; /* ppp unit we're connected to */
162 struct net *chan_net; /* the net channel belongs to */
163 struct list_head clist; /* link in list of channels per unit */
164 rwlock_t upl; /* protects `ppp' */
165 #ifdef CONFIG_PPP_MULTILINK
166 u8 avail; /* flag used in multilink stuff */
167 u8 had_frag; /* >= 1 fragments have been sent */
168 u32 lastseq; /* MP: last sequence # received */
169 int speed; /* speed of the corresponding ppp channel*/
170 #endif /* CONFIG_PPP_MULTILINK */
174 * SMP locking issues:
175 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
176 * list and the ppp.n_channels field, you need to take both locks
177 * before you modify them.
178 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
182 static DEFINE_MUTEX(ppp_mutex);
183 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
184 static atomic_t channel_count = ATOMIC_INIT(0);
186 /* per-net private data for this module */
187 static int ppp_net_id __read_mostly;
189 /* units to ppp mapping */
190 struct idr units_idr;
193 * all_ppp_mutex protects the units_idr mapping.
194 * It also ensures that finding a ppp unit in the units_idr
195 * map and updating its file.refcnt field is atomic.
197 struct mutex all_ppp_mutex;
200 struct list_head all_channels;
201 struct list_head new_channels;
202 int last_channel_index;
205 * all_channels_lock protects all_channels and
206 * last_channel_index, and the atomicity of find
207 * a channel and updating its file.refcnt field.
209 spinlock_t all_channels_lock;
212 /* Get the PPP protocol number from a skb */
213 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
215 /* We limit the length of ppp->file.rq to this (arbitrary) value */
216 #define PPP_MAX_RQLEN 32
219 * Maximum number of multilink fragments queued up.
220 * This has to be large enough to cope with the maximum latency of
221 * the slowest channel relative to the others. Strictly it should
222 * depend on the number of channels and their characteristics.
224 #define PPP_MP_MAX_QLEN 128
226 /* Multilink header bits. */
227 #define B 0x80 /* this fragment begins a packet */
228 #define E 0x40 /* this fragment ends a packet */
230 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
231 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
232 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
235 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
236 struct file *file, unsigned int cmd, unsigned long arg);
237 static void ppp_xmit_process(struct ppp *ppp);
238 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
239 static void ppp_push(struct ppp *ppp);
240 static void ppp_channel_push(struct channel *pch);
241 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
242 struct channel *pch);
243 static void ppp_receive_error(struct ppp *ppp);
244 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
245 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
246 struct sk_buff *skb);
247 #ifdef CONFIG_PPP_MULTILINK
248 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
249 struct channel *pch);
250 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
251 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
252 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
253 #endif /* CONFIG_PPP_MULTILINK */
254 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
255 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
256 static void ppp_ccp_closed(struct ppp *ppp);
257 static struct compressor *find_compressor(int type);
258 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
259 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
260 static void init_ppp_file(struct ppp_file *pf, int kind);
261 static void ppp_shutdown_interface(struct ppp *ppp);
262 static void ppp_destroy_interface(struct ppp *ppp);
263 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
264 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
265 static int ppp_connect_channel(struct channel *pch, int unit);
266 static int ppp_disconnect_channel(struct channel *pch);
267 static void ppp_destroy_channel(struct channel *pch);
268 static int unit_get(struct idr *p, void *ptr);
269 static int unit_set(struct idr *p, void *ptr, int n);
270 static void unit_put(struct idr *p, int n);
271 static void *unit_find(struct idr *p, int n);
273 static struct class *ppp_class;
275 /* per net-namespace data */
276 static inline struct ppp_net *ppp_pernet(struct net *net)
280 return net_generic(net, ppp_net_id);
283 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
284 static inline int proto_to_npindex(int proto)
303 /* Translates an NP index into a PPP protocol number */
304 static const int npindex_to_proto[NUM_NP] = {
313 /* Translates an ethertype into an NP index */
314 static inline int ethertype_to_npindex(int ethertype)
334 /* Translates an NP index into an ethertype */
335 static const int npindex_to_ethertype[NUM_NP] = {
347 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
348 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
349 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
350 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
351 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
352 ppp_recv_lock(ppp); } while (0)
353 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
354 ppp_xmit_unlock(ppp); } while (0)
357 * /dev/ppp device routines.
358 * The /dev/ppp device is used by pppd to control the ppp unit.
359 * It supports the read, write, ioctl and poll functions.
360 * Open instances of /dev/ppp can be in one of three states:
361 * unattached, attached to a ppp unit, or attached to a ppp channel.
363 static int ppp_open(struct inode *inode, struct file *file)
366 * This could (should?) be enforced by the permissions on /dev/ppp.
368 if (!capable(CAP_NET_ADMIN))
373 static int ppp_release(struct inode *unused, struct file *file)
375 struct ppp_file *pf = file->private_data;
379 file->private_data = NULL;
380 if (pf->kind == INTERFACE) {
382 if (file == ppp->owner)
383 ppp_shutdown_interface(ppp);
385 if (atomic_dec_and_test(&pf->refcnt)) {
388 ppp_destroy_interface(PF_TO_PPP(pf));
391 ppp_destroy_channel(PF_TO_CHANNEL(pf));
399 static ssize_t ppp_read(struct file *file, char __user *buf,
400 size_t count, loff_t *ppos)
402 struct ppp_file *pf = file->private_data;
403 DECLARE_WAITQUEUE(wait, current);
405 struct sk_buff *skb = NULL;
412 add_wait_queue(&pf->rwait, &wait);
414 set_current_state(TASK_INTERRUPTIBLE);
415 skb = skb_dequeue(&pf->rq);
421 if (pf->kind == INTERFACE) {
423 * Return 0 (EOF) on an interface that has no
424 * channels connected, unless it is looping
425 * network traffic (demand mode).
427 struct ppp *ppp = PF_TO_PPP(pf);
428 if (ppp->n_channels == 0 &&
429 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
433 if (file->f_flags & O_NONBLOCK)
436 if (signal_pending(current))
440 set_current_state(TASK_RUNNING);
441 remove_wait_queue(&pf->rwait, &wait);
447 if (skb->len > count)
452 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
462 static ssize_t ppp_write(struct file *file, const char __user *buf,
463 size_t count, loff_t *ppos)
465 struct ppp_file *pf = file->private_data;
472 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
475 skb_reserve(skb, pf->hdrlen);
477 if (copy_from_user(skb_put(skb, count), buf, count)) {
482 skb_queue_tail(&pf->xq, skb);
486 ppp_xmit_process(PF_TO_PPP(pf));
489 ppp_channel_push(PF_TO_CHANNEL(pf));
499 /* No kernel lock - fine */
500 static unsigned int ppp_poll(struct file *file, poll_table *wait)
502 struct ppp_file *pf = file->private_data;
507 poll_wait(file, &pf->rwait, wait);
508 mask = POLLOUT | POLLWRNORM;
509 if (skb_peek(&pf->rq))
510 mask |= POLLIN | POLLRDNORM;
513 else if (pf->kind == INTERFACE) {
514 /* see comment in ppp_read */
515 struct ppp *ppp = PF_TO_PPP(pf);
516 if (ppp->n_channels == 0 &&
517 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
518 mask |= POLLIN | POLLRDNORM;
524 #ifdef CONFIG_PPP_FILTER
525 static int get_filter(void __user *arg, struct sock_filter **p)
527 struct sock_fprog uprog;
528 struct sock_filter *code = NULL;
531 if (copy_from_user(&uprog, arg, sizeof(uprog)))
539 len = uprog.len * sizeof(struct sock_filter);
540 code = memdup_user(uprog.filter, len);
542 return PTR_ERR(code);
544 err = sk_chk_filter(code, uprog.len);
553 #endif /* CONFIG_PPP_FILTER */
555 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
557 struct ppp_file *pf = file->private_data;
559 int err = -EFAULT, val, val2, i;
560 struct ppp_idle idle;
563 struct slcompress *vj;
564 void __user *argp = (void __user *)arg;
565 int __user *p = argp;
568 return ppp_unattached_ioctl(current->nsproxy->net_ns,
571 if (cmd == PPPIOCDETACH) {
573 * We have to be careful here... if the file descriptor
574 * has been dup'd, we could have another process in the
575 * middle of a poll using the same file *, so we had
576 * better not free the interface data structures -
577 * instead we fail the ioctl. Even in this case, we
578 * shut down the interface if we are the owner of it.
579 * Actually, we should get rid of PPPIOCDETACH, userland
580 * (i.e. pppd) could achieve the same effect by closing
581 * this fd and reopening /dev/ppp.
584 mutex_lock(&ppp_mutex);
585 if (pf->kind == INTERFACE) {
587 if (file == ppp->owner)
588 ppp_shutdown_interface(ppp);
590 if (atomic_long_read(&file->f_count) <= 2) {
591 ppp_release(NULL, file);
594 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
595 atomic_long_read(&file->f_count));
596 mutex_unlock(&ppp_mutex);
600 if (pf->kind == CHANNEL) {
602 struct ppp_channel *chan;
604 mutex_lock(&ppp_mutex);
605 pch = PF_TO_CHANNEL(pf);
609 if (get_user(unit, p))
611 err = ppp_connect_channel(pch, unit);
615 err = ppp_disconnect_channel(pch);
619 down_read(&pch->chan_sem);
622 if (chan && chan->ops->ioctl)
623 err = chan->ops->ioctl(chan, cmd, arg);
624 up_read(&pch->chan_sem);
626 mutex_unlock(&ppp_mutex);
630 if (pf->kind != INTERFACE) {
632 printk(KERN_ERR "PPP: not interface or channel??\n");
636 mutex_lock(&ppp_mutex);
640 if (get_user(val, p))
647 if (get_user(val, p))
650 cflags = ppp->flags & ~val;
651 ppp->flags = val & SC_FLAG_BITS;
653 if (cflags & SC_CCP_OPEN)
659 val = ppp->flags | ppp->xstate | ppp->rstate;
660 if (put_user(val, p))
665 case PPPIOCSCOMPRESS:
666 err = ppp_set_compress(ppp, arg);
670 if (put_user(ppp->file.index, p))
676 if (get_user(val, p))
683 if (put_user(ppp->debug, p))
689 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
690 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
691 if (copy_to_user(argp, &idle, sizeof(idle)))
697 if (get_user(val, p))
700 if ((val >> 16) != 0) {
704 vj = slhc_init(val2+1, val+1);
706 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
720 if (copy_from_user(&npi, argp, sizeof(npi)))
722 err = proto_to_npindex(npi.protocol);
726 if (cmd == PPPIOCGNPMODE) {
728 npi.mode = ppp->npmode[i];
729 if (copy_to_user(argp, &npi, sizeof(npi)))
732 ppp->npmode[i] = npi.mode;
733 /* we may be able to transmit more packets now (??) */
734 netif_wake_queue(ppp->dev);
739 #ifdef CONFIG_PPP_FILTER
742 struct sock_filter *code;
743 err = get_filter(argp, &code);
746 kfree(ppp->pass_filter);
747 ppp->pass_filter = code;
756 struct sock_filter *code;
757 err = get_filter(argp, &code);
760 kfree(ppp->active_filter);
761 ppp->active_filter = code;
762 ppp->active_len = err;
768 #endif /* CONFIG_PPP_FILTER */
770 #ifdef CONFIG_PPP_MULTILINK
772 if (get_user(val, p))
776 ppp_recv_unlock(ppp);
779 #endif /* CONFIG_PPP_MULTILINK */
784 mutex_unlock(&ppp_mutex);
788 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
789 struct file *file, unsigned int cmd, unsigned long arg)
791 int unit, err = -EFAULT;
793 struct channel *chan;
795 int __user *p = (int __user *)arg;
797 mutex_lock(&ppp_mutex);
800 /* Create a new ppp unit */
801 if (get_user(unit, p))
803 ppp = ppp_create_interface(net, unit, &err);
806 file->private_data = &ppp->file;
809 if (put_user(ppp->file.index, p))
815 /* Attach to an existing ppp unit */
816 if (get_user(unit, p))
819 pn = ppp_pernet(net);
820 mutex_lock(&pn->all_ppp_mutex);
821 ppp = ppp_find_unit(pn, unit);
823 atomic_inc(&ppp->file.refcnt);
824 file->private_data = &ppp->file;
827 mutex_unlock(&pn->all_ppp_mutex);
831 if (get_user(unit, p))
834 pn = ppp_pernet(net);
835 spin_lock_bh(&pn->all_channels_lock);
836 chan = ppp_find_channel(pn, unit);
838 atomic_inc(&chan->file.refcnt);
839 file->private_data = &chan->file;
842 spin_unlock_bh(&pn->all_channels_lock);
848 mutex_unlock(&ppp_mutex);
852 static const struct file_operations ppp_device_fops = {
853 .owner = THIS_MODULE,
857 .unlocked_ioctl = ppp_ioctl,
859 .release = ppp_release,
860 .llseek = noop_llseek,
863 static __net_init int ppp_init_net(struct net *net)
865 struct ppp_net *pn = net_generic(net, ppp_net_id);
867 idr_init(&pn->units_idr);
868 mutex_init(&pn->all_ppp_mutex);
870 INIT_LIST_HEAD(&pn->all_channels);
871 INIT_LIST_HEAD(&pn->new_channels);
873 spin_lock_init(&pn->all_channels_lock);
878 static __net_exit void ppp_exit_net(struct net *net)
880 struct ppp_net *pn = net_generic(net, ppp_net_id);
882 idr_destroy(&pn->units_idr);
885 static struct pernet_operations ppp_net_ops = {
886 .init = ppp_init_net,
887 .exit = ppp_exit_net,
889 .size = sizeof(struct ppp_net),
892 #define PPP_MAJOR 108
894 /* Called at boot time if ppp is compiled into the kernel,
895 or at module load time (from init_module) if compiled as a module. */
896 static int __init ppp_init(void)
900 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
902 err = register_pernet_device(&ppp_net_ops);
904 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
908 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
910 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
914 ppp_class = class_create(THIS_MODULE, "ppp");
915 if (IS_ERR(ppp_class)) {
916 err = PTR_ERR(ppp_class);
920 /* not a big deal if we fail here :-) */
921 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
926 unregister_chrdev(PPP_MAJOR, "ppp");
928 unregister_pernet_device(&ppp_net_ops);
934 * Network interface unit routines.
937 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
939 struct ppp *ppp = netdev_priv(dev);
943 npi = ethertype_to_npindex(ntohs(skb->protocol));
947 /* Drop, accept or reject the packet */
948 switch (ppp->npmode[npi]) {
952 /* it would be nice to have a way to tell the network
953 system to queue this one up for later. */
960 /* Put the 2-byte PPP protocol number on the front,
961 making sure there is room for the address and control fields. */
962 if (skb_cow_head(skb, PPP_HDRLEN))
965 pp = skb_push(skb, 2);
966 proto = npindex_to_proto[npi];
970 netif_stop_queue(dev);
971 skb_queue_tail(&ppp->file.xq, skb);
972 ppp_xmit_process(ppp);
977 ++dev->stats.tx_dropped;
982 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
984 struct ppp *ppp = netdev_priv(dev);
986 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
987 struct ppp_stats stats;
988 struct ppp_comp_stats cstats;
993 ppp_get_stats(ppp, &stats);
994 if (copy_to_user(addr, &stats, sizeof(stats)))
1000 memset(&cstats, 0, sizeof(cstats));
1002 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1004 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1005 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1012 if (copy_to_user(addr, vers, strlen(vers) + 1))
1024 static const struct net_device_ops ppp_netdev_ops = {
1025 .ndo_start_xmit = ppp_start_xmit,
1026 .ndo_do_ioctl = ppp_net_ioctl,
1029 static void ppp_setup(struct net_device *dev)
1031 dev->netdev_ops = &ppp_netdev_ops;
1032 dev->hard_header_len = PPP_HDRLEN;
1035 dev->tx_queue_len = 3;
1036 dev->type = ARPHRD_PPP;
1037 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1038 dev->features |= NETIF_F_NETNS_LOCAL;
1039 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1043 * Transmit-side routines.
1047 * Called to do any work queued up on the transmit side
1048 * that can now be done.
1051 ppp_xmit_process(struct ppp *ppp)
1053 struct sk_buff *skb;
1056 if (!ppp->closing) {
1058 while (!ppp->xmit_pending &&
1059 (skb = skb_dequeue(&ppp->file.xq)))
1060 ppp_send_frame(ppp, skb);
1061 /* If there's no work left to do, tell the core net
1062 code that we can accept some more. */
1063 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1064 netif_wake_queue(ppp->dev);
1066 ppp_xmit_unlock(ppp);
1069 static inline struct sk_buff *
1070 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1072 struct sk_buff *new_skb;
1074 int new_skb_size = ppp->dev->mtu +
1075 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1076 int compressor_skb_size = ppp->dev->mtu +
1077 ppp->xcomp->comp_extra + PPP_HDRLEN;
1078 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1080 if (net_ratelimit())
1081 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1084 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1085 skb_reserve(new_skb,
1086 ppp->dev->hard_header_len - PPP_HDRLEN);
1088 /* compressor still expects A/C bytes in hdr */
1089 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1090 new_skb->data, skb->len + 2,
1091 compressor_skb_size);
1092 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1096 skb_pull(skb, 2); /* pull off A/C bytes */
1097 } else if (len == 0) {
1098 /* didn't compress, or CCP not up yet */
1104 * MPPE requires that we do not send unencrypted
1105 * frames. The compressor will return -1 if we
1106 * should drop the frame. We cannot simply test
1107 * the compress_proto because MPPE and MPPC share
1110 if (net_ratelimit())
1111 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1120 * Compress and send a frame.
1121 * The caller should have locked the xmit path,
1122 * and xmit_pending should be 0.
1125 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1127 int proto = PPP_PROTO(skb);
1128 struct sk_buff *new_skb;
1132 if (proto < 0x8000) {
1133 #ifdef CONFIG_PPP_FILTER
1134 /* check if we should pass this packet */
1135 /* the filter instructions are constructed assuming
1136 a four-byte PPP header on each packet */
1137 *skb_push(skb, 2) = 1;
1138 if (ppp->pass_filter &&
1139 sk_run_filter(skb, ppp->pass_filter) == 0) {
1141 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1145 /* if this packet passes the active filter, record the time */
1146 if (!(ppp->active_filter &&
1147 sk_run_filter(skb, ppp->active_filter) == 0))
1148 ppp->last_xmit = jiffies;
1151 /* for data packets, record the time */
1152 ppp->last_xmit = jiffies;
1153 #endif /* CONFIG_PPP_FILTER */
1156 ++ppp->dev->stats.tx_packets;
1157 ppp->dev->stats.tx_bytes += skb->len - 2;
1161 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1163 /* try to do VJ TCP header compression */
1164 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1167 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1170 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1172 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1173 new_skb->data + 2, &cp,
1174 !(ppp->flags & SC_NO_TCP_CCID));
1175 if (cp == skb->data + 2) {
1176 /* didn't compress */
1179 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1180 proto = PPP_VJC_COMP;
1181 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1183 proto = PPP_VJC_UNCOMP;
1184 cp[0] = skb->data[2];
1188 cp = skb_put(skb, len + 2);
1195 /* peek at outbound CCP frames */
1196 ppp_ccp_peek(ppp, skb, 0);
1200 /* try to do packet compression */
1201 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1202 proto != PPP_LCP && proto != PPP_CCP) {
1203 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1204 if (net_ratelimit())
1205 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1208 skb = pad_compress_skb(ppp, skb);
1214 * If we are waiting for traffic (demand dialling),
1215 * queue it up for pppd to receive.
1217 if (ppp->flags & SC_LOOP_TRAFFIC) {
1218 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1220 skb_queue_tail(&ppp->file.rq, skb);
1221 wake_up_interruptible(&ppp->file.rwait);
1225 ppp->xmit_pending = skb;
1231 ++ppp->dev->stats.tx_errors;
1235 * Try to send the frame in xmit_pending.
1236 * The caller should have the xmit path locked.
1239 ppp_push(struct ppp *ppp)
1241 struct list_head *list;
1242 struct channel *pch;
1243 struct sk_buff *skb = ppp->xmit_pending;
1248 list = &ppp->channels;
1249 if (list_empty(list)) {
1250 /* nowhere to send the packet, just drop it */
1251 ppp->xmit_pending = NULL;
1256 if ((ppp->flags & SC_MULTILINK) == 0) {
1257 /* not doing multilink: send it down the first channel */
1259 pch = list_entry(list, struct channel, clist);
1261 spin_lock_bh(&pch->downl);
1263 if (pch->chan->ops->start_xmit(pch->chan, skb))
1264 ppp->xmit_pending = NULL;
1266 /* channel got unregistered */
1268 ppp->xmit_pending = NULL;
1270 spin_unlock_bh(&pch->downl);
1274 #ifdef CONFIG_PPP_MULTILINK
1275 /* Multilink: fragment the packet over as many links
1276 as can take the packet at the moment. */
1277 if (!ppp_mp_explode(ppp, skb))
1279 #endif /* CONFIG_PPP_MULTILINK */
1281 ppp->xmit_pending = NULL;
1285 #ifdef CONFIG_PPP_MULTILINK
1287 * Divide a packet to be transmitted into fragments and
1288 * send them out the individual links.
1290 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1293 int i, bits, hdrlen, mtu;
1295 int navail, nfree, nzero;
1299 unsigned char *p, *q;
1300 struct list_head *list;
1301 struct channel *pch;
1302 struct sk_buff *frag;
1303 struct ppp_channel *chan;
1305 totspeed = 0; /*total bitrate of the bundle*/
1306 nfree = 0; /* # channels which have no packet already queued */
1307 navail = 0; /* total # of usable channels (not deregistered) */
1308 nzero = 0; /* number of channels with zero speed associated*/
1309 totfree = 0; /*total # of channels available and
1310 *having no queued packets before
1311 *starting the fragmentation*/
1313 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1315 list_for_each_entry(pch, &ppp->channels, clist) {
1319 pch->speed = pch->chan->speed;
1324 if (skb_queue_empty(&pch->file.xq) ||
1326 if (pch->speed == 0)
1329 totspeed += pch->speed;
1335 if (!pch->had_frag && i < ppp->nxchan)
1341 * Don't start sending this packet unless at least half of
1342 * the channels are free. This gives much better TCP
1343 * performance if we have a lot of channels.
1345 if (nfree == 0 || nfree < navail / 2)
1346 return 0; /* can't take now, leave it in xmit_pending */
1348 /* Do protocol field compression (XXX this should be optional) */
1357 nbigger = len % nfree;
1359 /* skip to the channel after the one we last used
1360 and start at that one */
1361 list = &ppp->channels;
1362 for (i = 0; i < ppp->nxchan; ++i) {
1364 if (list == &ppp->channels) {
1370 /* create a fragment for each channel */
1374 if (list == &ppp->channels) {
1378 pch = list_entry(list, struct channel, clist);
1384 * Skip this channel if it has a fragment pending already and
1385 * we haven't given a fragment to all of the free channels.
1387 if (pch->avail == 1) {
1394 /* check the channel's mtu and whether it is still attached. */
1395 spin_lock_bh(&pch->downl);
1396 if (pch->chan == NULL) {
1397 /* can't use this channel, it's being deregistered */
1398 if (pch->speed == 0)
1401 totspeed -= pch->speed;
1403 spin_unlock_bh(&pch->downl);
1414 *if the channel speed is not set divide
1415 *the packet evenly among the free channels;
1416 *otherwise divide it according to the speed
1417 *of the channel we are going to transmit on
1421 if (pch->speed == 0) {
1428 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1429 ((totspeed*totfree)/pch->speed)) - hdrlen;
1431 flen += ((totfree - nzero)*pch->speed)/totspeed;
1432 nbigger -= ((totfree - nzero)*pch->speed)/
1440 *check if we are on the last channel or
1441 *we exceded the lenght of the data to
1444 if ((nfree <= 0) || (flen > len))
1447 *it is not worth to tx on slow channels:
1448 *in that case from the resulting flen according to the
1449 *above formula will be equal or less than zero.
1450 *Skip the channel in this case
1454 spin_unlock_bh(&pch->downl);
1458 mtu = pch->chan->mtu - hdrlen;
1465 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1468 q = skb_put(frag, flen + hdrlen);
1470 /* make the MP header */
1473 if (ppp->flags & SC_MP_XSHORTSEQ) {
1474 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1478 q[3] = ppp->nxseq >> 16;
1479 q[4] = ppp->nxseq >> 8;
1483 memcpy(q + hdrlen, p, flen);
1485 /* try to send it down the channel */
1487 if (!skb_queue_empty(&pch->file.xq) ||
1488 !chan->ops->start_xmit(chan, frag))
1489 skb_queue_tail(&pch->file.xq, frag);
1495 spin_unlock_bh(&pch->downl);
1502 spin_unlock_bh(&pch->downl);
1504 printk(KERN_ERR "PPP: no memory (fragment)\n");
1505 ++ppp->dev->stats.tx_errors;
1507 return 1; /* abandon the frame */
1509 #endif /* CONFIG_PPP_MULTILINK */
1512 * Try to send data out on a channel.
1515 ppp_channel_push(struct channel *pch)
1517 struct sk_buff *skb;
1520 spin_lock_bh(&pch->downl);
1522 while (!skb_queue_empty(&pch->file.xq)) {
1523 skb = skb_dequeue(&pch->file.xq);
1524 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1525 /* put the packet back and try again later */
1526 skb_queue_head(&pch->file.xq, skb);
1531 /* channel got deregistered */
1532 skb_queue_purge(&pch->file.xq);
1534 spin_unlock_bh(&pch->downl);
1535 /* see if there is anything from the attached unit to be sent */
1536 if (skb_queue_empty(&pch->file.xq)) {
1537 read_lock_bh(&pch->upl);
1540 ppp_xmit_process(ppp);
1541 read_unlock_bh(&pch->upl);
1546 * Receive-side routines.
1549 struct ppp_mp_skb_parm {
1553 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1556 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1560 ppp_receive_frame(ppp, skb, pch);
1563 ppp_recv_unlock(ppp);
1567 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1569 struct channel *pch = chan->ppp;
1577 read_lock_bh(&pch->upl);
1578 if (!pskb_may_pull(skb, 2)) {
1581 ++pch->ppp->dev->stats.rx_length_errors;
1582 ppp_receive_error(pch->ppp);
1587 proto = PPP_PROTO(skb);
1588 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1589 /* put it on the channel queue */
1590 skb_queue_tail(&pch->file.rq, skb);
1591 /* drop old frames if queue too long */
1592 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1593 (skb = skb_dequeue(&pch->file.rq)))
1595 wake_up_interruptible(&pch->file.rwait);
1597 ppp_do_recv(pch->ppp, skb, pch);
1601 read_unlock_bh(&pch->upl);
1604 /* Put a 0-length skb in the receive queue as an error indication */
1606 ppp_input_error(struct ppp_channel *chan, int code)
1608 struct channel *pch = chan->ppp;
1609 struct sk_buff *skb;
1614 read_lock_bh(&pch->upl);
1616 skb = alloc_skb(0, GFP_ATOMIC);
1618 skb->len = 0; /* probably unnecessary */
1620 ppp_do_recv(pch->ppp, skb, pch);
1623 read_unlock_bh(&pch->upl);
1627 * We come in here to process a received frame.
1628 * The receive side of the ppp unit is locked.
1631 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1633 /* note: a 0-length skb is used as an error indication */
1635 #ifdef CONFIG_PPP_MULTILINK
1636 /* XXX do channel-level decompression here */
1637 if (PPP_PROTO(skb) == PPP_MP)
1638 ppp_receive_mp_frame(ppp, skb, pch);
1640 #endif /* CONFIG_PPP_MULTILINK */
1641 ppp_receive_nonmp_frame(ppp, skb);
1644 ppp_receive_error(ppp);
1649 ppp_receive_error(struct ppp *ppp)
1651 ++ppp->dev->stats.rx_errors;
1657 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1660 int proto, len, npi;
1663 * Decompress the frame, if compressed.
1664 * Note that some decompressors need to see uncompressed frames
1665 * that come in as well as compressed frames.
1667 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1668 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1669 skb = ppp_decompress_frame(ppp, skb);
1671 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1674 proto = PPP_PROTO(skb);
1677 /* decompress VJ compressed packets */
1678 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1681 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1682 /* copy to a new sk_buff with more tailroom */
1683 ns = dev_alloc_skb(skb->len + 128);
1685 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1689 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1694 skb->ip_summed = CHECKSUM_NONE;
1696 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1698 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1703 skb_put(skb, len - skb->len);
1704 else if (len < skb->len)
1709 case PPP_VJC_UNCOMP:
1710 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1713 /* Until we fix the decompressor need to make sure
1714 * data portion is linear.
1716 if (!pskb_may_pull(skb, skb->len))
1719 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1720 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1727 ppp_ccp_peek(ppp, skb, 1);
1731 ++ppp->dev->stats.rx_packets;
1732 ppp->dev->stats.rx_bytes += skb->len - 2;
1734 npi = proto_to_npindex(proto);
1736 /* control or unknown frame - pass it to pppd */
1737 skb_queue_tail(&ppp->file.rq, skb);
1738 /* limit queue length by dropping old frames */
1739 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1740 (skb = skb_dequeue(&ppp->file.rq)))
1742 /* wake up any process polling or blocking on read */
1743 wake_up_interruptible(&ppp->file.rwait);
1746 /* network protocol frame - give it to the kernel */
1748 #ifdef CONFIG_PPP_FILTER
1749 /* check if the packet passes the pass and active filters */
1750 /* the filter instructions are constructed assuming
1751 a four-byte PPP header on each packet */
1752 if (ppp->pass_filter || ppp->active_filter) {
1753 if (skb_cloned(skb) &&
1754 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1757 *skb_push(skb, 2) = 0;
1758 if (ppp->pass_filter &&
1759 sk_run_filter(skb, ppp->pass_filter) == 0) {
1761 printk(KERN_DEBUG "PPP: inbound frame "
1766 if (!(ppp->active_filter &&
1767 sk_run_filter(skb, ppp->active_filter) == 0))
1768 ppp->last_recv = jiffies;
1771 #endif /* CONFIG_PPP_FILTER */
1772 ppp->last_recv = jiffies;
1774 if ((ppp->dev->flags & IFF_UP) == 0 ||
1775 ppp->npmode[npi] != NPMODE_PASS) {
1778 /* chop off protocol */
1779 skb_pull_rcsum(skb, 2);
1780 skb->dev = ppp->dev;
1781 skb->protocol = htons(npindex_to_ethertype[npi]);
1782 skb_reset_mac_header(skb);
1790 ppp_receive_error(ppp);
1793 static struct sk_buff *
1794 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1796 int proto = PPP_PROTO(skb);
1800 /* Until we fix all the decompressor's need to make sure
1801 * data portion is linear.
1803 if (!pskb_may_pull(skb, skb->len))
1806 if (proto == PPP_COMP) {
1809 switch(ppp->rcomp->compress_proto) {
1811 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1814 obuff_size = ppp->mru + PPP_HDRLEN;
1818 ns = dev_alloc_skb(obuff_size);
1820 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1823 /* the decompressor still expects the A/C bytes in the hdr */
1824 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1825 skb->len + 2, ns->data, obuff_size);
1827 /* Pass the compressed frame to pppd as an
1828 error indication. */
1829 if (len == DECOMP_FATALERROR)
1830 ppp->rstate |= SC_DC_FERROR;
1838 skb_pull(skb, 2); /* pull off the A/C bytes */
1841 /* Uncompressed frame - pass to decompressor so it
1842 can update its dictionary if necessary. */
1843 if (ppp->rcomp->incomp)
1844 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1851 ppp->rstate |= SC_DC_ERROR;
1852 ppp_receive_error(ppp);
1856 #ifdef CONFIG_PPP_MULTILINK
1858 * Receive a multilink frame.
1859 * We put it on the reconstruction queue and then pull off
1860 * as many completed frames as we can.
1863 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1867 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1869 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1870 goto err; /* no good, throw it away */
1872 /* Decode sequence number and begin/end bits */
1873 if (ppp->flags & SC_MP_SHORTSEQ) {
1874 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1877 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1880 PPP_MP_CB(skb)->BEbits = skb->data[2];
1881 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1884 * Do protocol ID decompression on the first fragment of each packet.
1886 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1887 *skb_push(skb, 1) = 0;
1890 * Expand sequence number to 32 bits, making it as close
1891 * as possible to ppp->minseq.
1893 seq |= ppp->minseq & ~mask;
1894 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1896 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1897 seq -= mask + 1; /* should never happen */
1898 PPP_MP_CB(skb)->sequence = seq;
1902 * If this packet comes before the next one we were expecting,
1905 if (seq_before(seq, ppp->nextseq)) {
1907 ++ppp->dev->stats.rx_dropped;
1908 ppp_receive_error(ppp);
1913 * Reevaluate minseq, the minimum over all channels of the
1914 * last sequence number received on each channel. Because of
1915 * the increasing sequence number rule, we know that any fragment
1916 * before `minseq' which hasn't arrived is never going to arrive.
1917 * The list of channels can't change because we have the receive
1918 * side of the ppp unit locked.
1920 list_for_each_entry(ch, &ppp->channels, clist) {
1921 if (seq_before(ch->lastseq, seq))
1924 if (seq_before(ppp->minseq, seq))
1927 /* Put the fragment on the reconstruction queue */
1928 ppp_mp_insert(ppp, skb);
1930 /* If the queue is getting long, don't wait any longer for packets
1931 before the start of the queue. */
1932 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1933 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1934 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
1935 ppp->minseq = PPP_MP_CB(mskb)->sequence;
1938 /* Pull completed packets off the queue and receive them. */
1939 while ((skb = ppp_mp_reconstruct(ppp))) {
1940 if (pskb_may_pull(skb, 2))
1941 ppp_receive_nonmp_frame(ppp, skb);
1943 ++ppp->dev->stats.rx_length_errors;
1945 ppp_receive_error(ppp);
1953 ppp_receive_error(ppp);
1957 * Insert a fragment on the MP reconstruction queue.
1958 * The queue is ordered by increasing sequence number.
1961 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1964 struct sk_buff_head *list = &ppp->mrq;
1965 u32 seq = PPP_MP_CB(skb)->sequence;
1967 /* N.B. we don't need to lock the list lock because we have the
1968 ppp unit receive-side lock. */
1969 skb_queue_walk(list, p) {
1970 if (seq_before(seq, PPP_MP_CB(p)->sequence))
1973 __skb_queue_before(list, p, skb);
1977 * Reconstruct a packet from the MP fragment queue.
1978 * We go through increasing sequence numbers until we find a
1979 * complete packet, or we get to the sequence number for a fragment
1980 * which hasn't arrived but might still do so.
1982 static struct sk_buff *
1983 ppp_mp_reconstruct(struct ppp *ppp)
1985 u32 seq = ppp->nextseq;
1986 u32 minseq = ppp->minseq;
1987 struct sk_buff_head *list = &ppp->mrq;
1988 struct sk_buff *p, *next;
1989 struct sk_buff *head, *tail;
1990 struct sk_buff *skb = NULL;
1991 int lost = 0, len = 0;
1993 if (ppp->mrru == 0) /* do nothing until mrru is set */
1997 for (p = head; p != (struct sk_buff *) list; p = next) {
1999 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2000 /* this can't happen, anyway ignore the skb */
2001 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2002 PPP_MP_CB(p)->sequence, seq);
2006 if (PPP_MP_CB(p)->sequence != seq) {
2007 /* Fragment `seq' is missing. If it is after
2008 minseq, it might arrive later, so stop here. */
2009 if (seq_after(seq, minseq))
2011 /* Fragment `seq' is lost, keep going. */
2013 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2014 minseq + 1: PPP_MP_CB(p)->sequence;
2020 * At this point we know that all the fragments from
2021 * ppp->nextseq to seq are either present or lost.
2022 * Also, there are no complete packets in the queue
2023 * that have no missing fragments and end before this
2027 /* B bit set indicates this fragment starts a packet */
2028 if (PPP_MP_CB(p)->BEbits & B) {
2036 /* Got a complete packet yet? */
2037 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2038 (PPP_MP_CB(head)->BEbits & B)) {
2039 if (len > ppp->mrru + 2) {
2040 ++ppp->dev->stats.rx_length_errors;
2041 printk(KERN_DEBUG "PPP: reconstructed packet"
2042 " is too long (%d)\n", len);
2043 } else if (p == head) {
2044 /* fragment is complete packet - reuse skb */
2048 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2049 ++ppp->dev->stats.rx_missed_errors;
2050 printk(KERN_DEBUG "PPP: no memory for "
2051 "reconstructed packet");
2056 ppp->nextseq = seq + 1;
2060 * If this is the ending fragment of a packet,
2061 * and we haven't found a complete valid packet yet,
2062 * we can discard up to and including this fragment.
2064 if (PPP_MP_CB(p)->BEbits & E)
2070 /* If we have a complete packet, copy it all into one skb. */
2072 /* If we have discarded any fragments,
2073 signal a receive error. */
2074 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2076 printk(KERN_DEBUG " missed pkts %u..%u\n",
2078 PPP_MP_CB(head)->sequence-1);
2079 ++ppp->dev->stats.rx_dropped;
2080 ppp_receive_error(ppp);
2084 /* copy to a single skb */
2085 for (p = head; p != tail->next; p = p->next)
2086 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2087 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2091 /* Discard all the skbuffs that we have copied the data out of
2092 or that we can't use. */
2093 while ((p = list->next) != head) {
2094 __skb_unlink(p, list);
2100 #endif /* CONFIG_PPP_MULTILINK */
2103 * Channel interface.
2106 /* Create a new, unattached ppp channel. */
2107 int ppp_register_channel(struct ppp_channel *chan)
2109 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2112 /* Create a new, unattached ppp channel for specified net. */
2113 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2115 struct channel *pch;
2118 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2122 pn = ppp_pernet(net);
2126 pch->chan_net = net;
2128 init_ppp_file(&pch->file, CHANNEL);
2129 pch->file.hdrlen = chan->hdrlen;
2130 #ifdef CONFIG_PPP_MULTILINK
2132 #endif /* CONFIG_PPP_MULTILINK */
2133 init_rwsem(&pch->chan_sem);
2134 spin_lock_init(&pch->downl);
2135 rwlock_init(&pch->upl);
2137 spin_lock_bh(&pn->all_channels_lock);
2138 pch->file.index = ++pn->last_channel_index;
2139 list_add(&pch->list, &pn->new_channels);
2140 atomic_inc(&channel_count);
2141 spin_unlock_bh(&pn->all_channels_lock);
2147 * Return the index of a channel.
2149 int ppp_channel_index(struct ppp_channel *chan)
2151 struct channel *pch = chan->ppp;
2154 return pch->file.index;
2159 * Return the PPP unit number to which a channel is connected.
2161 int ppp_unit_number(struct ppp_channel *chan)
2163 struct channel *pch = chan->ppp;
2167 read_lock_bh(&pch->upl);
2169 unit = pch->ppp->file.index;
2170 read_unlock_bh(&pch->upl);
2176 * Return the PPP device interface name of a channel.
2178 char *ppp_dev_name(struct ppp_channel *chan)
2180 struct channel *pch = chan->ppp;
2184 read_lock_bh(&pch->upl);
2185 if (pch->ppp && pch->ppp->dev)
2186 name = pch->ppp->dev->name;
2187 read_unlock_bh(&pch->upl);
2194 * Disconnect a channel from the generic layer.
2195 * This must be called in process context.
2198 ppp_unregister_channel(struct ppp_channel *chan)
2200 struct channel *pch = chan->ppp;
2204 return; /* should never happen */
2209 * This ensures that we have returned from any calls into the
2210 * the channel's start_xmit or ioctl routine before we proceed.
2212 down_write(&pch->chan_sem);
2213 spin_lock_bh(&pch->downl);
2215 spin_unlock_bh(&pch->downl);
2216 up_write(&pch->chan_sem);
2217 ppp_disconnect_channel(pch);
2219 pn = ppp_pernet(pch->chan_net);
2220 spin_lock_bh(&pn->all_channels_lock);
2221 list_del(&pch->list);
2222 spin_unlock_bh(&pn->all_channels_lock);
2225 wake_up_interruptible(&pch->file.rwait);
2226 if (atomic_dec_and_test(&pch->file.refcnt))
2227 ppp_destroy_channel(pch);
2231 * Callback from a channel when it can accept more to transmit.
2232 * This should be called at BH/softirq level, not interrupt level.
2235 ppp_output_wakeup(struct ppp_channel *chan)
2237 struct channel *pch = chan->ppp;
2241 ppp_channel_push(pch);
2245 * Compression control.
2248 /* Process the PPPIOCSCOMPRESS ioctl. */
2250 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2253 struct compressor *cp, *ocomp;
2254 struct ppp_option_data data;
2255 void *state, *ostate;
2256 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2259 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2260 (data.length <= CCP_MAX_OPTION_LENGTH &&
2261 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2264 if (data.length > CCP_MAX_OPTION_LENGTH ||
2265 ccp_option[1] < 2 || ccp_option[1] > data.length)
2268 cp = try_then_request_module(
2269 find_compressor(ccp_option[0]),
2270 "ppp-compress-%d", ccp_option[0]);
2275 if (data.transmit) {
2276 state = cp->comp_alloc(ccp_option, data.length);
2279 ppp->xstate &= ~SC_COMP_RUN;
2281 ostate = ppp->xc_state;
2283 ppp->xc_state = state;
2284 ppp_xmit_unlock(ppp);
2286 ocomp->comp_free(ostate);
2287 module_put(ocomp->owner);
2291 module_put(cp->owner);
2294 state = cp->decomp_alloc(ccp_option, data.length);
2297 ppp->rstate &= ~SC_DECOMP_RUN;
2299 ostate = ppp->rc_state;
2301 ppp->rc_state = state;
2302 ppp_recv_unlock(ppp);
2304 ocomp->decomp_free(ostate);
2305 module_put(ocomp->owner);
2309 module_put(cp->owner);
2317 * Look at a CCP packet and update our state accordingly.
2318 * We assume the caller has the xmit or recv path locked.
2321 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2326 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2327 return; /* no header */
2330 switch (CCP_CODE(dp)) {
2333 /* A ConfReq starts negotiation of compression
2334 * in one direction of transmission,
2335 * and hence brings it down...but which way?
2338 * A ConfReq indicates what the sender would like to receive
2341 /* He is proposing what I should send */
2342 ppp->xstate &= ~SC_COMP_RUN;
2344 /* I am proposing to what he should send */
2345 ppp->rstate &= ~SC_DECOMP_RUN;
2352 * CCP is going down, both directions of transmission
2354 ppp->rstate &= ~SC_DECOMP_RUN;
2355 ppp->xstate &= ~SC_COMP_RUN;
2359 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2361 len = CCP_LENGTH(dp);
2362 if (!pskb_may_pull(skb, len + 2))
2363 return; /* too short */
2366 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2369 /* we will start receiving compressed packets */
2372 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2373 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2374 ppp->rstate |= SC_DECOMP_RUN;
2375 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2378 /* we will soon start sending compressed packets */
2381 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2382 ppp->file.index, 0, ppp->debug))
2383 ppp->xstate |= SC_COMP_RUN;
2388 /* reset the [de]compressor */
2389 if ((ppp->flags & SC_CCP_UP) == 0)
2392 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2393 ppp->rcomp->decomp_reset(ppp->rc_state);
2394 ppp->rstate &= ~SC_DC_ERROR;
2397 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2398 ppp->xcomp->comp_reset(ppp->xc_state);
2404 /* Free up compression resources. */
2406 ppp_ccp_closed(struct ppp *ppp)
2408 void *xstate, *rstate;
2409 struct compressor *xcomp, *rcomp;
2412 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2415 xstate = ppp->xc_state;
2416 ppp->xc_state = NULL;
2419 rstate = ppp->rc_state;
2420 ppp->rc_state = NULL;
2424 xcomp->comp_free(xstate);
2425 module_put(xcomp->owner);
2428 rcomp->decomp_free(rstate);
2429 module_put(rcomp->owner);
2433 /* List of compressors. */
2434 static LIST_HEAD(compressor_list);
2435 static DEFINE_SPINLOCK(compressor_list_lock);
2437 struct compressor_entry {
2438 struct list_head list;
2439 struct compressor *comp;
2442 static struct compressor_entry *
2443 find_comp_entry(int proto)
2445 struct compressor_entry *ce;
2447 list_for_each_entry(ce, &compressor_list, list) {
2448 if (ce->comp->compress_proto == proto)
2454 /* Register a compressor */
2456 ppp_register_compressor(struct compressor *cp)
2458 struct compressor_entry *ce;
2460 spin_lock(&compressor_list_lock);
2462 if (find_comp_entry(cp->compress_proto))
2465 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2470 list_add(&ce->list, &compressor_list);
2472 spin_unlock(&compressor_list_lock);
2476 /* Unregister a compressor */
2478 ppp_unregister_compressor(struct compressor *cp)
2480 struct compressor_entry *ce;
2482 spin_lock(&compressor_list_lock);
2483 ce = find_comp_entry(cp->compress_proto);
2484 if (ce && ce->comp == cp) {
2485 list_del(&ce->list);
2488 spin_unlock(&compressor_list_lock);
2491 /* Find a compressor. */
2492 static struct compressor *
2493 find_compressor(int type)
2495 struct compressor_entry *ce;
2496 struct compressor *cp = NULL;
2498 spin_lock(&compressor_list_lock);
2499 ce = find_comp_entry(type);
2502 if (!try_module_get(cp->owner))
2505 spin_unlock(&compressor_list_lock);
2510 * Miscelleneous stuff.
2514 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2516 struct slcompress *vj = ppp->vj;
2518 memset(st, 0, sizeof(*st));
2519 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2520 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2521 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2522 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2523 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2524 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2527 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2528 st->vj.vjs_compressed = vj->sls_o_compressed;
2529 st->vj.vjs_searches = vj->sls_o_searches;
2530 st->vj.vjs_misses = vj->sls_o_misses;
2531 st->vj.vjs_errorin = vj->sls_i_error;
2532 st->vj.vjs_tossed = vj->sls_i_tossed;
2533 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2534 st->vj.vjs_compressedin = vj->sls_i_compressed;
2538 * Stuff for handling the lists of ppp units and channels
2539 * and for initialization.
2543 * Create a new ppp interface unit. Fails if it can't allocate memory
2544 * or if there is already a unit with the requested number.
2545 * unit == -1 means allocate a new number.
2548 ppp_create_interface(struct net *net, int unit, int *retp)
2552 struct net_device *dev = NULL;
2556 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2560 pn = ppp_pernet(net);
2562 ppp = netdev_priv(dev);
2565 init_ppp_file(&ppp->file, INTERFACE);
2566 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2567 for (i = 0; i < NUM_NP; ++i)
2568 ppp->npmode[i] = NPMODE_PASS;
2569 INIT_LIST_HEAD(&ppp->channels);
2570 spin_lock_init(&ppp->rlock);
2571 spin_lock_init(&ppp->wlock);
2572 #ifdef CONFIG_PPP_MULTILINK
2574 skb_queue_head_init(&ppp->mrq);
2575 #endif /* CONFIG_PPP_MULTILINK */
2578 * drum roll: don't forget to set
2579 * the net device is belong to
2581 dev_net_set(dev, net);
2583 mutex_lock(&pn->all_ppp_mutex);
2586 unit = unit_get(&pn->units_idr, ppp);
2593 if (unit_find(&pn->units_idr, unit))
2594 goto out2; /* unit already exists */
2596 * if caller need a specified unit number
2597 * lets try to satisfy him, otherwise --
2598 * he should better ask us for new unit number
2600 * NOTE: yes I know that returning EEXIST it's not
2601 * fair but at least pppd will ask us to allocate
2602 * new unit in this case so user is happy :)
2604 unit = unit_set(&pn->units_idr, ppp, unit);
2609 /* Initialize the new ppp unit */
2610 ppp->file.index = unit;
2611 sprintf(dev->name, "ppp%d", unit);
2613 ret = register_netdev(dev);
2615 unit_put(&pn->units_idr, unit);
2616 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2623 atomic_inc(&ppp_unit_count);
2624 mutex_unlock(&pn->all_ppp_mutex);
2630 mutex_unlock(&pn->all_ppp_mutex);
2638 * Initialize a ppp_file structure.
2641 init_ppp_file(struct ppp_file *pf, int kind)
2644 skb_queue_head_init(&pf->xq);
2645 skb_queue_head_init(&pf->rq);
2646 atomic_set(&pf->refcnt, 1);
2647 init_waitqueue_head(&pf->rwait);
2651 * Take down a ppp interface unit - called when the owning file
2652 * (the one that created the unit) is closed or detached.
2654 static void ppp_shutdown_interface(struct ppp *ppp)
2658 pn = ppp_pernet(ppp->ppp_net);
2659 mutex_lock(&pn->all_ppp_mutex);
2661 /* This will call dev_close() for us. */
2663 if (!ppp->closing) {
2666 unregister_netdev(ppp->dev);
2667 unit_put(&pn->units_idr, ppp->file.index);
2673 wake_up_interruptible(&ppp->file.rwait);
2675 mutex_unlock(&pn->all_ppp_mutex);
2679 * Free the memory used by a ppp unit. This is only called once
2680 * there are no channels connected to the unit and no file structs
2681 * that reference the unit.
2683 static void ppp_destroy_interface(struct ppp *ppp)
2685 atomic_dec(&ppp_unit_count);
2687 if (!ppp->file.dead || ppp->n_channels) {
2688 /* "can't happen" */
2689 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2690 "n_channels=%d !\n", ppp, ppp->file.dead,
2695 ppp_ccp_closed(ppp);
2700 skb_queue_purge(&ppp->file.xq);
2701 skb_queue_purge(&ppp->file.rq);
2702 #ifdef CONFIG_PPP_MULTILINK
2703 skb_queue_purge(&ppp->mrq);
2704 #endif /* CONFIG_PPP_MULTILINK */
2705 #ifdef CONFIG_PPP_FILTER
2706 kfree(ppp->pass_filter);
2707 ppp->pass_filter = NULL;
2708 kfree(ppp->active_filter);
2709 ppp->active_filter = NULL;
2710 #endif /* CONFIG_PPP_FILTER */
2712 kfree_skb(ppp->xmit_pending);
2714 free_netdev(ppp->dev);
2718 * Locate an existing ppp unit.
2719 * The caller should have locked the all_ppp_mutex.
2722 ppp_find_unit(struct ppp_net *pn, int unit)
2724 return unit_find(&pn->units_idr, unit);
2728 * Locate an existing ppp channel.
2729 * The caller should have locked the all_channels_lock.
2730 * First we look in the new_channels list, then in the
2731 * all_channels list. If found in the new_channels list,
2732 * we move it to the all_channels list. This is for speed
2733 * when we have a lot of channels in use.
2735 static struct channel *
2736 ppp_find_channel(struct ppp_net *pn, int unit)
2738 struct channel *pch;
2740 list_for_each_entry(pch, &pn->new_channels, list) {
2741 if (pch->file.index == unit) {
2742 list_move(&pch->list, &pn->all_channels);
2747 list_for_each_entry(pch, &pn->all_channels, list) {
2748 if (pch->file.index == unit)
2756 * Connect a PPP channel to a PPP interface unit.
2759 ppp_connect_channel(struct channel *pch, int unit)
2766 pn = ppp_pernet(pch->chan_net);
2768 mutex_lock(&pn->all_ppp_mutex);
2769 ppp = ppp_find_unit(pn, unit);
2772 write_lock_bh(&pch->upl);
2778 if (pch->file.hdrlen > ppp->file.hdrlen)
2779 ppp->file.hdrlen = pch->file.hdrlen;
2780 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2781 if (hdrlen > ppp->dev->hard_header_len)
2782 ppp->dev->hard_header_len = hdrlen;
2783 list_add_tail(&pch->clist, &ppp->channels);
2786 atomic_inc(&ppp->file.refcnt);
2791 write_unlock_bh(&pch->upl);
2793 mutex_unlock(&pn->all_ppp_mutex);
2798 * Disconnect a channel from its ppp unit.
2801 ppp_disconnect_channel(struct channel *pch)
2806 write_lock_bh(&pch->upl);
2809 write_unlock_bh(&pch->upl);
2811 /* remove it from the ppp unit's list */
2813 list_del(&pch->clist);
2814 if (--ppp->n_channels == 0)
2815 wake_up_interruptible(&ppp->file.rwait);
2817 if (atomic_dec_and_test(&ppp->file.refcnt))
2818 ppp_destroy_interface(ppp);
2825 * Free up the resources used by a ppp channel.
2827 static void ppp_destroy_channel(struct channel *pch)
2829 atomic_dec(&channel_count);
2831 if (!pch->file.dead) {
2832 /* "can't happen" */
2833 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2837 skb_queue_purge(&pch->file.xq);
2838 skb_queue_purge(&pch->file.rq);
2842 static void __exit ppp_cleanup(void)
2844 /* should never happen */
2845 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2846 printk(KERN_ERR "PPP: removing module but units remain!\n");
2847 unregister_chrdev(PPP_MAJOR, "ppp");
2848 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2849 class_destroy(ppp_class);
2850 unregister_pernet_device(&ppp_net_ops);
2854 * Units handling. Caller must protect concurrent access
2855 * by holding all_ppp_mutex
2858 static int __unit_alloc(struct idr *p, void *ptr, int n)
2863 if (!idr_pre_get(p, GFP_KERNEL)) {
2864 printk(KERN_ERR "PPP: No free memory for idr\n");
2868 err = idr_get_new_above(p, ptr, n, &unit);
2878 /* associate pointer with specified number */
2879 static int unit_set(struct idr *p, void *ptr, int n)
2883 unit = __unit_alloc(p, ptr, n);
2886 else if (unit != n) {
2887 idr_remove(p, unit);
2894 /* get new free unit number and associate pointer with it */
2895 static int unit_get(struct idr *p, void *ptr)
2897 return __unit_alloc(p, ptr, 0);
2900 /* put unit number back to a pool */
2901 static void unit_put(struct idr *p, int n)
2906 /* get pointer associated with the number */
2907 static void *unit_find(struct idr *p, int n)
2909 return idr_find(p, n);
2912 /* Module/initialization stuff */
2914 module_init(ppp_init);
2915 module_exit(ppp_cleanup);
2917 EXPORT_SYMBOL(ppp_register_net_channel);
2918 EXPORT_SYMBOL(ppp_register_channel);
2919 EXPORT_SYMBOL(ppp_unregister_channel);
2920 EXPORT_SYMBOL(ppp_channel_index);
2921 EXPORT_SYMBOL(ppp_unit_number);
2922 EXPORT_SYMBOL(ppp_dev_name);
2923 EXPORT_SYMBOL(ppp_input);
2924 EXPORT_SYMBOL(ppp_input_error);
2925 EXPORT_SYMBOL(ppp_output_wakeup);
2926 EXPORT_SYMBOL(ppp_register_compressor);
2927 EXPORT_SYMBOL(ppp_unregister_compressor);
2928 MODULE_LICENSE("GPL");
2929 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2930 MODULE_ALIAS("devname:ppp");