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 bpf_prog *pass_filter; /* filter for packets to pass */
147 struct bpf_prog *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,
273 struct file *file, int *retp);
274 static void init_ppp_file(struct ppp_file *pf, int kind);
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 const struct net_device_ops ppp_netdev_ops;
288 static struct class *ppp_class;
290 /* per net-namespace data */
291 static inline struct ppp_net *ppp_pernet(struct net *net)
295 return net_generic(net, ppp_net_id);
298 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
299 static inline int proto_to_npindex(int proto)
318 /* Translates an NP index into a PPP protocol number */
319 static const int npindex_to_proto[NUM_NP] = {
328 /* Translates an ethertype into an NP index */
329 static inline int ethertype_to_npindex(int ethertype)
349 /* Translates an NP index into an ethertype */
350 static const int npindex_to_ethertype[NUM_NP] = {
362 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
363 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
364 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
365 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
366 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
367 ppp_recv_lock(ppp); } while (0)
368 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
369 ppp_xmit_unlock(ppp); } while (0)
372 * /dev/ppp device routines.
373 * The /dev/ppp device is used by pppd to control the ppp unit.
374 * It supports the read, write, ioctl and poll functions.
375 * Open instances of /dev/ppp can be in one of three states:
376 * unattached, attached to a ppp unit, or attached to a ppp channel.
378 static int ppp_open(struct inode *inode, struct file *file)
381 * This could (should?) be enforced by the permissions on /dev/ppp.
383 if (!capable(CAP_NET_ADMIN))
388 static int ppp_release(struct inode *unused, struct file *file)
390 struct ppp_file *pf = file->private_data;
394 file->private_data = NULL;
395 if (pf->kind == INTERFACE) {
398 if (file == ppp->owner)
399 unregister_netdevice(ppp->dev);
402 if (atomic_dec_and_test(&pf->refcnt)) {
405 ppp_destroy_interface(PF_TO_PPP(pf));
408 ppp_destroy_channel(PF_TO_CHANNEL(pf));
416 static ssize_t ppp_read(struct file *file, char __user *buf,
417 size_t count, loff_t *ppos)
419 struct ppp_file *pf = file->private_data;
420 DECLARE_WAITQUEUE(wait, current);
422 struct sk_buff *skb = NULL;
430 add_wait_queue(&pf->rwait, &wait);
432 set_current_state(TASK_INTERRUPTIBLE);
433 skb = skb_dequeue(&pf->rq);
439 if (pf->kind == INTERFACE) {
441 * Return 0 (EOF) on an interface that has no
442 * channels connected, unless it is looping
443 * network traffic (demand mode).
445 struct ppp *ppp = PF_TO_PPP(pf);
446 if (ppp->n_channels == 0 &&
447 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
451 if (file->f_flags & O_NONBLOCK)
454 if (signal_pending(current))
458 set_current_state(TASK_RUNNING);
459 remove_wait_queue(&pf->rwait, &wait);
465 if (skb->len > count)
470 iov_iter_init(&to, READ, &iov, 1, count);
471 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
481 static ssize_t ppp_write(struct file *file, const char __user *buf,
482 size_t count, loff_t *ppos)
484 struct ppp_file *pf = file->private_data;
491 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
494 skb_reserve(skb, pf->hdrlen);
496 if (copy_from_user(skb_put(skb, count), buf, count)) {
501 skb_queue_tail(&pf->xq, skb);
505 ppp_xmit_process(PF_TO_PPP(pf));
508 ppp_channel_push(PF_TO_CHANNEL(pf));
518 /* No kernel lock - fine */
519 static unsigned int ppp_poll(struct file *file, poll_table *wait)
521 struct ppp_file *pf = file->private_data;
526 poll_wait(file, &pf->rwait, wait);
527 mask = POLLOUT | POLLWRNORM;
528 if (skb_peek(&pf->rq))
529 mask |= POLLIN | POLLRDNORM;
532 else if (pf->kind == INTERFACE) {
533 /* see comment in ppp_read */
534 struct ppp *ppp = PF_TO_PPP(pf);
535 if (ppp->n_channels == 0 &&
536 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
537 mask |= POLLIN | POLLRDNORM;
543 #ifdef CONFIG_PPP_FILTER
544 static int get_filter(void __user *arg, struct sock_filter **p)
546 struct sock_fprog uprog;
547 struct sock_filter *code = NULL;
550 if (copy_from_user(&uprog, arg, sizeof(uprog)))
558 len = uprog.len * sizeof(struct sock_filter);
559 code = memdup_user(uprog.filter, len);
561 return PTR_ERR(code);
566 #endif /* CONFIG_PPP_FILTER */
568 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
572 int err = -EFAULT, val, val2, i;
573 struct ppp_idle idle;
576 struct slcompress *vj;
577 void __user *argp = (void __user *)arg;
578 int __user *p = argp;
580 mutex_lock(&ppp_mutex);
582 pf = file->private_data;
584 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
589 if (cmd == PPPIOCDETACH) {
591 * We have to be careful here... if the file descriptor
592 * has been dup'd, we could have another process in the
593 * middle of a poll using the same file *, so we had
594 * better not free the interface data structures -
595 * instead we fail the ioctl. Even in this case, we
596 * shut down the interface if we are the owner of it.
597 * Actually, we should get rid of PPPIOCDETACH, userland
598 * (i.e. pppd) could achieve the same effect by closing
599 * this fd and reopening /dev/ppp.
602 if (pf->kind == INTERFACE) {
605 if (file == ppp->owner)
606 unregister_netdevice(ppp->dev);
609 if (atomic_long_read(&file->f_count) < 2) {
610 ppp_release(NULL, file);
613 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
614 atomic_long_read(&file->f_count));
618 if (pf->kind == CHANNEL) {
620 struct ppp_channel *chan;
622 pch = PF_TO_CHANNEL(pf);
626 if (get_user(unit, p))
628 err = ppp_connect_channel(pch, unit);
632 err = ppp_disconnect_channel(pch);
636 down_read(&pch->chan_sem);
639 if (chan && chan->ops->ioctl)
640 err = chan->ops->ioctl(chan, cmd, arg);
641 up_read(&pch->chan_sem);
646 if (pf->kind != INTERFACE) {
648 pr_err("PPP: not interface or channel??\n");
656 if (get_user(val, p))
663 if (get_user(val, p))
666 cflags = ppp->flags & ~val;
667 #ifdef CONFIG_PPP_MULTILINK
668 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
671 ppp->flags = val & SC_FLAG_BITS;
673 if (cflags & SC_CCP_OPEN)
679 val = ppp->flags | ppp->xstate | ppp->rstate;
680 if (put_user(val, p))
685 case PPPIOCSCOMPRESS:
686 err = ppp_set_compress(ppp, arg);
690 if (put_user(ppp->file.index, p))
696 if (get_user(val, p))
703 if (put_user(ppp->debug, p))
709 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
710 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
711 if (copy_to_user(argp, &idle, sizeof(idle)))
717 if (get_user(val, p))
720 if ((val >> 16) != 0) {
724 vj = slhc_init(val2+1, val+1);
739 if (copy_from_user(&npi, argp, sizeof(npi)))
741 err = proto_to_npindex(npi.protocol);
745 if (cmd == PPPIOCGNPMODE) {
747 npi.mode = ppp->npmode[i];
748 if (copy_to_user(argp, &npi, sizeof(npi)))
751 ppp->npmode[i] = npi.mode;
752 /* we may be able to transmit more packets now (??) */
753 netif_wake_queue(ppp->dev);
758 #ifdef CONFIG_PPP_FILTER
761 struct sock_filter *code;
763 err = get_filter(argp, &code);
765 struct bpf_prog *pass_filter = NULL;
766 struct sock_fprog_kern fprog = {
773 err = bpf_prog_create(&pass_filter, &fprog);
776 if (ppp->pass_filter)
777 bpf_prog_destroy(ppp->pass_filter);
778 ppp->pass_filter = pass_filter;
787 struct sock_filter *code;
789 err = get_filter(argp, &code);
791 struct bpf_prog *active_filter = NULL;
792 struct sock_fprog_kern fprog = {
799 err = bpf_prog_create(&active_filter, &fprog);
802 if (ppp->active_filter)
803 bpf_prog_destroy(ppp->active_filter);
804 ppp->active_filter = active_filter;
811 #endif /* CONFIG_PPP_FILTER */
813 #ifdef CONFIG_PPP_MULTILINK
815 if (get_user(val, p))
819 ppp_recv_unlock(ppp);
822 #endif /* CONFIG_PPP_MULTILINK */
829 mutex_unlock(&ppp_mutex);
834 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
835 struct file *file, unsigned int cmd, unsigned long arg)
837 int unit, err = -EFAULT;
839 struct channel *chan;
841 int __user *p = (int __user *)arg;
845 /* Create a new ppp unit */
846 if (get_user(unit, p))
848 ppp = ppp_create_interface(net, unit, file, &err);
851 file->private_data = &ppp->file;
853 if (put_user(ppp->file.index, p))
859 /* Attach to an existing ppp unit */
860 if (get_user(unit, p))
863 pn = ppp_pernet(net);
864 mutex_lock(&pn->all_ppp_mutex);
865 ppp = ppp_find_unit(pn, unit);
867 atomic_inc(&ppp->file.refcnt);
868 file->private_data = &ppp->file;
871 mutex_unlock(&pn->all_ppp_mutex);
875 if (get_user(unit, p))
878 pn = ppp_pernet(net);
879 spin_lock_bh(&pn->all_channels_lock);
880 chan = ppp_find_channel(pn, unit);
882 atomic_inc(&chan->file.refcnt);
883 file->private_data = &chan->file;
886 spin_unlock_bh(&pn->all_channels_lock);
896 static const struct file_operations ppp_device_fops = {
897 .owner = THIS_MODULE,
901 .unlocked_ioctl = ppp_ioctl,
903 .release = ppp_release,
904 .llseek = noop_llseek,
907 static __net_init int ppp_init_net(struct net *net)
909 struct ppp_net *pn = net_generic(net, ppp_net_id);
911 idr_init(&pn->units_idr);
912 mutex_init(&pn->all_ppp_mutex);
914 INIT_LIST_HEAD(&pn->all_channels);
915 INIT_LIST_HEAD(&pn->new_channels);
917 spin_lock_init(&pn->all_channels_lock);
922 static __net_exit void ppp_exit_net(struct net *net)
924 struct ppp_net *pn = net_generic(net, ppp_net_id);
925 struct net_device *dev;
926 struct net_device *aux;
932 for_each_netdev_safe(net, dev, aux) {
933 if (dev->netdev_ops == &ppp_netdev_ops)
934 unregister_netdevice_queue(dev, &list);
937 idr_for_each_entry(&pn->units_idr, ppp, id)
938 /* Skip devices already unregistered by previous loop */
939 if (!net_eq(dev_net(ppp->dev), net))
940 unregister_netdevice_queue(ppp->dev, &list);
942 unregister_netdevice_many(&list);
945 idr_destroy(&pn->units_idr);
948 static struct pernet_operations ppp_net_ops = {
949 .init = ppp_init_net,
950 .exit = ppp_exit_net,
952 .size = sizeof(struct ppp_net),
955 #define PPP_MAJOR 108
957 /* Called at boot time if ppp is compiled into the kernel,
958 or at module load time (from init_module) if compiled as a module. */
959 static int __init ppp_init(void)
963 pr_info("PPP generic driver version " PPP_VERSION "\n");
965 err = register_pernet_device(&ppp_net_ops);
967 pr_err("failed to register PPP pernet device (%d)\n", err);
971 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
973 pr_err("failed to register PPP device (%d)\n", err);
977 ppp_class = class_create(THIS_MODULE, "ppp");
978 if (IS_ERR(ppp_class)) {
979 err = PTR_ERR(ppp_class);
983 /* not a big deal if we fail here :-) */
984 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
989 unregister_chrdev(PPP_MAJOR, "ppp");
991 unregister_pernet_device(&ppp_net_ops);
997 * Network interface unit routines.
1000 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1002 struct ppp *ppp = netdev_priv(dev);
1006 npi = ethertype_to_npindex(ntohs(skb->protocol));
1010 /* Drop, accept or reject the packet */
1011 switch (ppp->npmode[npi]) {
1015 /* it would be nice to have a way to tell the network
1016 system to queue this one up for later. */
1023 /* Put the 2-byte PPP protocol number on the front,
1024 making sure there is room for the address and control fields. */
1025 if (skb_cow_head(skb, PPP_HDRLEN))
1028 pp = skb_push(skb, 2);
1029 proto = npindex_to_proto[npi];
1030 put_unaligned_be16(proto, pp);
1032 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1033 skb_queue_tail(&ppp->file.xq, skb);
1034 ppp_xmit_process(ppp);
1035 return NETDEV_TX_OK;
1039 ++dev->stats.tx_dropped;
1040 return NETDEV_TX_OK;
1044 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1046 struct ppp *ppp = netdev_priv(dev);
1048 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1049 struct ppp_stats stats;
1050 struct ppp_comp_stats cstats;
1055 ppp_get_stats(ppp, &stats);
1056 if (copy_to_user(addr, &stats, sizeof(stats)))
1061 case SIOCGPPPCSTATS:
1062 memset(&cstats, 0, sizeof(cstats));
1064 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1066 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1067 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1074 if (copy_to_user(addr, vers, strlen(vers) + 1))
1086 static struct rtnl_link_stats64*
1087 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1089 struct ppp *ppp = netdev_priv(dev);
1092 stats64->rx_packets = ppp->stats64.rx_packets;
1093 stats64->rx_bytes = ppp->stats64.rx_bytes;
1094 ppp_recv_unlock(ppp);
1097 stats64->tx_packets = ppp->stats64.tx_packets;
1098 stats64->tx_bytes = ppp->stats64.tx_bytes;
1099 ppp_xmit_unlock(ppp);
1101 stats64->rx_errors = dev->stats.rx_errors;
1102 stats64->tx_errors = dev->stats.tx_errors;
1103 stats64->rx_dropped = dev->stats.rx_dropped;
1104 stats64->tx_dropped = dev->stats.tx_dropped;
1105 stats64->rx_length_errors = dev->stats.rx_length_errors;
1110 static struct lock_class_key ppp_tx_busylock;
1111 static int ppp_dev_init(struct net_device *dev)
1113 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1117 static void ppp_dev_uninit(struct net_device *dev)
1119 struct ppp *ppp = netdev_priv(dev);
1120 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1126 mutex_lock(&pn->all_ppp_mutex);
1127 unit_put(&pn->units_idr, ppp->file.index);
1128 mutex_unlock(&pn->all_ppp_mutex);
1133 wake_up_interruptible(&ppp->file.rwait);
1136 static const struct net_device_ops ppp_netdev_ops = {
1137 .ndo_init = ppp_dev_init,
1138 .ndo_uninit = ppp_dev_uninit,
1139 .ndo_start_xmit = ppp_start_xmit,
1140 .ndo_do_ioctl = ppp_net_ioctl,
1141 .ndo_get_stats64 = ppp_get_stats64,
1144 static void ppp_setup(struct net_device *dev)
1146 dev->netdev_ops = &ppp_netdev_ops;
1147 dev->hard_header_len = PPP_HDRLEN;
1150 dev->tx_queue_len = 3;
1151 dev->type = ARPHRD_PPP;
1152 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1153 netif_keep_dst(dev);
1157 * Transmit-side routines.
1161 * Called to do any work queued up on the transmit side
1162 * that can now be done.
1165 ppp_xmit_process(struct ppp *ppp)
1167 struct sk_buff *skb;
1170 if (!ppp->closing) {
1172 while (!ppp->xmit_pending &&
1173 (skb = skb_dequeue(&ppp->file.xq)))
1174 ppp_send_frame(ppp, skb);
1175 /* If there's no work left to do, tell the core net
1176 code that we can accept some more. */
1177 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1178 netif_wake_queue(ppp->dev);
1180 netif_stop_queue(ppp->dev);
1182 ppp_xmit_unlock(ppp);
1185 static inline struct sk_buff *
1186 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1188 struct sk_buff *new_skb;
1190 int new_skb_size = ppp->dev->mtu +
1191 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1192 int compressor_skb_size = ppp->dev->mtu +
1193 ppp->xcomp->comp_extra + PPP_HDRLEN;
1194 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1196 if (net_ratelimit())
1197 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1200 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1201 skb_reserve(new_skb,
1202 ppp->dev->hard_header_len - PPP_HDRLEN);
1204 /* compressor still expects A/C bytes in hdr */
1205 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1206 new_skb->data, skb->len + 2,
1207 compressor_skb_size);
1208 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1212 skb_pull(skb, 2); /* pull off A/C bytes */
1213 } else if (len == 0) {
1214 /* didn't compress, or CCP not up yet */
1215 consume_skb(new_skb);
1220 * MPPE requires that we do not send unencrypted
1221 * frames. The compressor will return -1 if we
1222 * should drop the frame. We cannot simply test
1223 * the compress_proto because MPPE and MPPC share
1226 if (net_ratelimit())
1227 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1229 consume_skb(new_skb);
1236 * Compress and send a frame.
1237 * The caller should have locked the xmit path,
1238 * and xmit_pending should be 0.
1241 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1243 int proto = PPP_PROTO(skb);
1244 struct sk_buff *new_skb;
1248 if (proto < 0x8000) {
1249 #ifdef CONFIG_PPP_FILTER
1250 /* check if we should pass this packet */
1251 /* the filter instructions are constructed assuming
1252 a four-byte PPP header on each packet */
1253 *skb_push(skb, 2) = 1;
1254 if (ppp->pass_filter &&
1255 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1257 netdev_printk(KERN_DEBUG, ppp->dev,
1258 "PPP: outbound frame "
1263 /* if this packet passes the active filter, record the time */
1264 if (!(ppp->active_filter &&
1265 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1266 ppp->last_xmit = jiffies;
1269 /* for data packets, record the time */
1270 ppp->last_xmit = jiffies;
1271 #endif /* CONFIG_PPP_FILTER */
1274 ++ppp->stats64.tx_packets;
1275 ppp->stats64.tx_bytes += skb->len - 2;
1279 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1281 /* try to do VJ TCP header compression */
1282 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1285 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1288 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1290 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1291 new_skb->data + 2, &cp,
1292 !(ppp->flags & SC_NO_TCP_CCID));
1293 if (cp == skb->data + 2) {
1294 /* didn't compress */
1295 consume_skb(new_skb);
1297 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1298 proto = PPP_VJC_COMP;
1299 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1301 proto = PPP_VJC_UNCOMP;
1302 cp[0] = skb->data[2];
1306 cp = skb_put(skb, len + 2);
1313 /* peek at outbound CCP frames */
1314 ppp_ccp_peek(ppp, skb, 0);
1318 /* try to do packet compression */
1319 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1320 proto != PPP_LCP && proto != PPP_CCP) {
1321 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1322 if (net_ratelimit())
1323 netdev_err(ppp->dev,
1324 "ppp: compression required but "
1325 "down - pkt dropped.\n");
1328 skb = pad_compress_skb(ppp, skb);
1334 * If we are waiting for traffic (demand dialling),
1335 * queue it up for pppd to receive.
1337 if (ppp->flags & SC_LOOP_TRAFFIC) {
1338 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1340 skb_queue_tail(&ppp->file.rq, skb);
1341 wake_up_interruptible(&ppp->file.rwait);
1345 ppp->xmit_pending = skb;
1351 ++ppp->dev->stats.tx_errors;
1355 * Try to send the frame in xmit_pending.
1356 * The caller should have the xmit path locked.
1359 ppp_push(struct ppp *ppp)
1361 struct list_head *list;
1362 struct channel *pch;
1363 struct sk_buff *skb = ppp->xmit_pending;
1368 list = &ppp->channels;
1369 if (list_empty(list)) {
1370 /* nowhere to send the packet, just drop it */
1371 ppp->xmit_pending = NULL;
1376 if ((ppp->flags & SC_MULTILINK) == 0) {
1377 /* not doing multilink: send it down the first channel */
1379 pch = list_entry(list, struct channel, clist);
1381 spin_lock_bh(&pch->downl);
1383 if (pch->chan->ops->start_xmit(pch->chan, skb))
1384 ppp->xmit_pending = NULL;
1386 /* channel got unregistered */
1388 ppp->xmit_pending = NULL;
1390 spin_unlock_bh(&pch->downl);
1394 #ifdef CONFIG_PPP_MULTILINK
1395 /* Multilink: fragment the packet over as many links
1396 as can take the packet at the moment. */
1397 if (!ppp_mp_explode(ppp, skb))
1399 #endif /* CONFIG_PPP_MULTILINK */
1401 ppp->xmit_pending = NULL;
1405 #ifdef CONFIG_PPP_MULTILINK
1406 static bool mp_protocol_compress __read_mostly = true;
1407 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1408 MODULE_PARM_DESC(mp_protocol_compress,
1409 "compress protocol id in multilink fragments");
1412 * Divide a packet to be transmitted into fragments and
1413 * send them out the individual links.
1415 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1418 int i, bits, hdrlen, mtu;
1420 int navail, nfree, nzero;
1424 unsigned char *p, *q;
1425 struct list_head *list;
1426 struct channel *pch;
1427 struct sk_buff *frag;
1428 struct ppp_channel *chan;
1430 totspeed = 0; /*total bitrate of the bundle*/
1431 nfree = 0; /* # channels which have no packet already queued */
1432 navail = 0; /* total # of usable channels (not deregistered) */
1433 nzero = 0; /* number of channels with zero speed associated*/
1434 totfree = 0; /*total # of channels available and
1435 *having no queued packets before
1436 *starting the fragmentation*/
1438 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1440 list_for_each_entry(pch, &ppp->channels, clist) {
1444 pch->speed = pch->chan->speed;
1449 if (skb_queue_empty(&pch->file.xq) ||
1451 if (pch->speed == 0)
1454 totspeed += pch->speed;
1460 if (!pch->had_frag && i < ppp->nxchan)
1466 * Don't start sending this packet unless at least half of
1467 * the channels are free. This gives much better TCP
1468 * performance if we have a lot of channels.
1470 if (nfree == 0 || nfree < navail / 2)
1471 return 0; /* can't take now, leave it in xmit_pending */
1473 /* Do protocol field compression */
1476 if (*p == 0 && mp_protocol_compress) {
1482 nbigger = len % nfree;
1484 /* skip to the channel after the one we last used
1485 and start at that one */
1486 list = &ppp->channels;
1487 for (i = 0; i < ppp->nxchan; ++i) {
1489 if (list == &ppp->channels) {
1495 /* create a fragment for each channel */
1499 if (list == &ppp->channels) {
1503 pch = list_entry(list, struct channel, clist);
1509 * Skip this channel if it has a fragment pending already and
1510 * we haven't given a fragment to all of the free channels.
1512 if (pch->avail == 1) {
1519 /* check the channel's mtu and whether it is still attached. */
1520 spin_lock_bh(&pch->downl);
1521 if (pch->chan == NULL) {
1522 /* can't use this channel, it's being deregistered */
1523 if (pch->speed == 0)
1526 totspeed -= pch->speed;
1528 spin_unlock_bh(&pch->downl);
1539 *if the channel speed is not set divide
1540 *the packet evenly among the free channels;
1541 *otherwise divide it according to the speed
1542 *of the channel we are going to transmit on
1546 if (pch->speed == 0) {
1553 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1554 ((totspeed*totfree)/pch->speed)) - hdrlen;
1556 flen += ((totfree - nzero)*pch->speed)/totspeed;
1557 nbigger -= ((totfree - nzero)*pch->speed)/
1565 *check if we are on the last channel or
1566 *we exceded the length of the data to
1569 if ((nfree <= 0) || (flen > len))
1572 *it is not worth to tx on slow channels:
1573 *in that case from the resulting flen according to the
1574 *above formula will be equal or less than zero.
1575 *Skip the channel in this case
1579 spin_unlock_bh(&pch->downl);
1584 * hdrlen includes the 2-byte PPP protocol field, but the
1585 * MTU counts only the payload excluding the protocol field.
1586 * (RFC1661 Section 2)
1588 mtu = pch->chan->mtu - (hdrlen - 2);
1595 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1598 q = skb_put(frag, flen + hdrlen);
1600 /* make the MP header */
1601 put_unaligned_be16(PPP_MP, q);
1602 if (ppp->flags & SC_MP_XSHORTSEQ) {
1603 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1607 q[3] = ppp->nxseq >> 16;
1608 q[4] = ppp->nxseq >> 8;
1612 memcpy(q + hdrlen, p, flen);
1614 /* try to send it down the channel */
1616 if (!skb_queue_empty(&pch->file.xq) ||
1617 !chan->ops->start_xmit(chan, frag))
1618 skb_queue_tail(&pch->file.xq, frag);
1624 spin_unlock_bh(&pch->downl);
1631 spin_unlock_bh(&pch->downl);
1633 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1634 ++ppp->dev->stats.tx_errors;
1636 return 1; /* abandon the frame */
1638 #endif /* CONFIG_PPP_MULTILINK */
1641 * Try to send data out on a channel.
1644 ppp_channel_push(struct channel *pch)
1646 struct sk_buff *skb;
1649 spin_lock_bh(&pch->downl);
1651 while (!skb_queue_empty(&pch->file.xq)) {
1652 skb = skb_dequeue(&pch->file.xq);
1653 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1654 /* put the packet back and try again later */
1655 skb_queue_head(&pch->file.xq, skb);
1660 /* channel got deregistered */
1661 skb_queue_purge(&pch->file.xq);
1663 spin_unlock_bh(&pch->downl);
1664 /* see if there is anything from the attached unit to be sent */
1665 if (skb_queue_empty(&pch->file.xq)) {
1666 read_lock_bh(&pch->upl);
1669 ppp_xmit_process(ppp);
1670 read_unlock_bh(&pch->upl);
1675 * Receive-side routines.
1678 struct ppp_mp_skb_parm {
1682 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1685 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1689 ppp_receive_frame(ppp, skb, pch);
1692 ppp_recv_unlock(ppp);
1696 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1698 struct channel *pch = chan->ppp;
1706 read_lock_bh(&pch->upl);
1707 if (!pskb_may_pull(skb, 2)) {
1710 ++pch->ppp->dev->stats.rx_length_errors;
1711 ppp_receive_error(pch->ppp);
1716 proto = PPP_PROTO(skb);
1717 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1718 /* put it on the channel queue */
1719 skb_queue_tail(&pch->file.rq, skb);
1720 /* drop old frames if queue too long */
1721 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1722 (skb = skb_dequeue(&pch->file.rq)))
1724 wake_up_interruptible(&pch->file.rwait);
1726 ppp_do_recv(pch->ppp, skb, pch);
1730 read_unlock_bh(&pch->upl);
1733 /* Put a 0-length skb in the receive queue as an error indication */
1735 ppp_input_error(struct ppp_channel *chan, int code)
1737 struct channel *pch = chan->ppp;
1738 struct sk_buff *skb;
1743 read_lock_bh(&pch->upl);
1745 skb = alloc_skb(0, GFP_ATOMIC);
1747 skb->len = 0; /* probably unnecessary */
1749 ppp_do_recv(pch->ppp, skb, pch);
1752 read_unlock_bh(&pch->upl);
1756 * We come in here to process a received frame.
1757 * The receive side of the ppp unit is locked.
1760 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1762 /* note: a 0-length skb is used as an error indication */
1764 skb_checksum_complete_unset(skb);
1765 #ifdef CONFIG_PPP_MULTILINK
1766 /* XXX do channel-level decompression here */
1767 if (PPP_PROTO(skb) == PPP_MP)
1768 ppp_receive_mp_frame(ppp, skb, pch);
1770 #endif /* CONFIG_PPP_MULTILINK */
1771 ppp_receive_nonmp_frame(ppp, skb);
1774 ppp_receive_error(ppp);
1779 ppp_receive_error(struct ppp *ppp)
1781 ++ppp->dev->stats.rx_errors;
1787 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1790 int proto, len, npi;
1793 * Decompress the frame, if compressed.
1794 * Note that some decompressors need to see uncompressed frames
1795 * that come in as well as compressed frames.
1797 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1798 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1799 skb = ppp_decompress_frame(ppp, skb);
1801 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1804 proto = PPP_PROTO(skb);
1807 /* decompress VJ compressed packets */
1808 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1811 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1812 /* copy to a new sk_buff with more tailroom */
1813 ns = dev_alloc_skb(skb->len + 128);
1815 netdev_err(ppp->dev, "PPP: no memory "
1820 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1825 skb->ip_summed = CHECKSUM_NONE;
1827 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1829 netdev_printk(KERN_DEBUG, ppp->dev,
1830 "PPP: VJ decompression error\n");
1835 skb_put(skb, len - skb->len);
1836 else if (len < skb->len)
1841 case PPP_VJC_UNCOMP:
1842 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1845 /* Until we fix the decompressor need to make sure
1846 * data portion is linear.
1848 if (!pskb_may_pull(skb, skb->len))
1851 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1852 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1859 ppp_ccp_peek(ppp, skb, 1);
1863 ++ppp->stats64.rx_packets;
1864 ppp->stats64.rx_bytes += skb->len - 2;
1866 npi = proto_to_npindex(proto);
1868 /* control or unknown frame - pass it to pppd */
1869 skb_queue_tail(&ppp->file.rq, skb);
1870 /* limit queue length by dropping old frames */
1871 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1872 (skb = skb_dequeue(&ppp->file.rq)))
1874 /* wake up any process polling or blocking on read */
1875 wake_up_interruptible(&ppp->file.rwait);
1878 /* network protocol frame - give it to the kernel */
1880 #ifdef CONFIG_PPP_FILTER
1881 /* check if the packet passes the pass and active filters */
1882 /* the filter instructions are constructed assuming
1883 a four-byte PPP header on each packet */
1884 if (ppp->pass_filter || ppp->active_filter) {
1885 if (skb_unclone(skb, GFP_ATOMIC))
1888 *skb_push(skb, 2) = 0;
1889 if (ppp->pass_filter &&
1890 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1892 netdev_printk(KERN_DEBUG, ppp->dev,
1893 "PPP: inbound frame "
1898 if (!(ppp->active_filter &&
1899 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1900 ppp->last_recv = jiffies;
1903 #endif /* CONFIG_PPP_FILTER */
1904 ppp->last_recv = jiffies;
1906 if ((ppp->dev->flags & IFF_UP) == 0 ||
1907 ppp->npmode[npi] != NPMODE_PASS) {
1910 /* chop off protocol */
1911 skb_pull_rcsum(skb, 2);
1912 skb->dev = ppp->dev;
1913 skb->protocol = htons(npindex_to_ethertype[npi]);
1914 skb_reset_mac_header(skb);
1915 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
1916 dev_net(ppp->dev)));
1924 ppp_receive_error(ppp);
1927 static struct sk_buff *
1928 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1930 int proto = PPP_PROTO(skb);
1934 /* Until we fix all the decompressor's need to make sure
1935 * data portion is linear.
1937 if (!pskb_may_pull(skb, skb->len))
1940 if (proto == PPP_COMP) {
1943 switch(ppp->rcomp->compress_proto) {
1945 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1948 obuff_size = ppp->mru + PPP_HDRLEN;
1952 ns = dev_alloc_skb(obuff_size);
1954 netdev_err(ppp->dev, "ppp_decompress_frame: "
1958 /* the decompressor still expects the A/C bytes in the hdr */
1959 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1960 skb->len + 2, ns->data, obuff_size);
1962 /* Pass the compressed frame to pppd as an
1963 error indication. */
1964 if (len == DECOMP_FATALERROR)
1965 ppp->rstate |= SC_DC_FERROR;
1973 skb_pull(skb, 2); /* pull off the A/C bytes */
1976 /* Uncompressed frame - pass to decompressor so it
1977 can update its dictionary if necessary. */
1978 if (ppp->rcomp->incomp)
1979 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1986 ppp->rstate |= SC_DC_ERROR;
1987 ppp_receive_error(ppp);
1991 #ifdef CONFIG_PPP_MULTILINK
1993 * Receive a multilink frame.
1994 * We put it on the reconstruction queue and then pull off
1995 * as many completed frames as we can.
1998 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2002 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2004 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2005 goto err; /* no good, throw it away */
2007 /* Decode sequence number and begin/end bits */
2008 if (ppp->flags & SC_MP_SHORTSEQ) {
2009 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2012 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2015 PPP_MP_CB(skb)->BEbits = skb->data[2];
2016 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2019 * Do protocol ID decompression on the first fragment of each packet.
2021 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2022 *skb_push(skb, 1) = 0;
2025 * Expand sequence number to 32 bits, making it as close
2026 * as possible to ppp->minseq.
2028 seq |= ppp->minseq & ~mask;
2029 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2031 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2032 seq -= mask + 1; /* should never happen */
2033 PPP_MP_CB(skb)->sequence = seq;
2037 * If this packet comes before the next one we were expecting,
2040 if (seq_before(seq, ppp->nextseq)) {
2042 ++ppp->dev->stats.rx_dropped;
2043 ppp_receive_error(ppp);
2048 * Reevaluate minseq, the minimum over all channels of the
2049 * last sequence number received on each channel. Because of
2050 * the increasing sequence number rule, we know that any fragment
2051 * before `minseq' which hasn't arrived is never going to arrive.
2052 * The list of channels can't change because we have the receive
2053 * side of the ppp unit locked.
2055 list_for_each_entry(ch, &ppp->channels, clist) {
2056 if (seq_before(ch->lastseq, seq))
2059 if (seq_before(ppp->minseq, seq))
2062 /* Put the fragment on the reconstruction queue */
2063 ppp_mp_insert(ppp, skb);
2065 /* If the queue is getting long, don't wait any longer for packets
2066 before the start of the queue. */
2067 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2068 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2069 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2070 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2073 /* Pull completed packets off the queue and receive them. */
2074 while ((skb = ppp_mp_reconstruct(ppp))) {
2075 if (pskb_may_pull(skb, 2))
2076 ppp_receive_nonmp_frame(ppp, skb);
2078 ++ppp->dev->stats.rx_length_errors;
2080 ppp_receive_error(ppp);
2088 ppp_receive_error(ppp);
2092 * Insert a fragment on the MP reconstruction queue.
2093 * The queue is ordered by increasing sequence number.
2096 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2099 struct sk_buff_head *list = &ppp->mrq;
2100 u32 seq = PPP_MP_CB(skb)->sequence;
2102 /* N.B. we don't need to lock the list lock because we have the
2103 ppp unit receive-side lock. */
2104 skb_queue_walk(list, p) {
2105 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2108 __skb_queue_before(list, p, skb);
2112 * Reconstruct a packet from the MP fragment queue.
2113 * We go through increasing sequence numbers until we find a
2114 * complete packet, or we get to the sequence number for a fragment
2115 * which hasn't arrived but might still do so.
2117 static struct sk_buff *
2118 ppp_mp_reconstruct(struct ppp *ppp)
2120 u32 seq = ppp->nextseq;
2121 u32 minseq = ppp->minseq;
2122 struct sk_buff_head *list = &ppp->mrq;
2123 struct sk_buff *p, *tmp;
2124 struct sk_buff *head, *tail;
2125 struct sk_buff *skb = NULL;
2126 int lost = 0, len = 0;
2128 if (ppp->mrru == 0) /* do nothing until mrru is set */
2132 skb_queue_walk_safe(list, p, tmp) {
2134 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2135 /* this can't happen, anyway ignore the skb */
2136 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2138 PPP_MP_CB(p)->sequence, seq);
2139 __skb_unlink(p, list);
2143 if (PPP_MP_CB(p)->sequence != seq) {
2145 /* Fragment `seq' is missing. If it is after
2146 minseq, it might arrive later, so stop here. */
2147 if (seq_after(seq, minseq))
2149 /* Fragment `seq' is lost, keep going. */
2152 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2153 minseq + 1: PPP_MP_CB(p)->sequence;
2156 netdev_printk(KERN_DEBUG, ppp->dev,
2157 "lost frag %u..%u\n",
2164 * At this point we know that all the fragments from
2165 * ppp->nextseq to seq are either present or lost.
2166 * Also, there are no complete packets in the queue
2167 * that have no missing fragments and end before this
2171 /* B bit set indicates this fragment starts a packet */
2172 if (PPP_MP_CB(p)->BEbits & B) {
2180 /* Got a complete packet yet? */
2181 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2182 (PPP_MP_CB(head)->BEbits & B)) {
2183 if (len > ppp->mrru + 2) {
2184 ++ppp->dev->stats.rx_length_errors;
2185 netdev_printk(KERN_DEBUG, ppp->dev,
2186 "PPP: reconstructed packet"
2187 " is too long (%d)\n", len);
2192 ppp->nextseq = seq + 1;
2196 * If this is the ending fragment of a packet,
2197 * and we haven't found a complete valid packet yet,
2198 * we can discard up to and including this fragment.
2200 if (PPP_MP_CB(p)->BEbits & E) {
2201 struct sk_buff *tmp2;
2203 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2205 netdev_printk(KERN_DEBUG, ppp->dev,
2206 "discarding frag %u\n",
2207 PPP_MP_CB(p)->sequence);
2208 __skb_unlink(p, list);
2211 head = skb_peek(list);
2218 /* If we have a complete packet, copy it all into one skb. */
2220 /* If we have discarded any fragments,
2221 signal a receive error. */
2222 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2223 skb_queue_walk_safe(list, p, tmp) {
2227 netdev_printk(KERN_DEBUG, ppp->dev,
2228 "discarding frag %u\n",
2229 PPP_MP_CB(p)->sequence);
2230 __skb_unlink(p, list);
2235 netdev_printk(KERN_DEBUG, ppp->dev,
2236 " missed pkts %u..%u\n",
2238 PPP_MP_CB(head)->sequence-1);
2239 ++ppp->dev->stats.rx_dropped;
2240 ppp_receive_error(ppp);
2245 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2246 p = skb_queue_next(list, head);
2247 __skb_unlink(skb, list);
2248 skb_queue_walk_from_safe(list, p, tmp) {
2249 __skb_unlink(p, list);
2255 skb->data_len += p->len;
2256 skb->truesize += p->truesize;
2262 __skb_unlink(skb, list);
2265 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2270 #endif /* CONFIG_PPP_MULTILINK */
2273 * Channel interface.
2276 /* Create a new, unattached ppp channel. */
2277 int ppp_register_channel(struct ppp_channel *chan)
2279 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2282 /* Create a new, unattached ppp channel for specified net. */
2283 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2285 struct channel *pch;
2288 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2292 pn = ppp_pernet(net);
2296 pch->chan_net = get_net(net);
2298 init_ppp_file(&pch->file, CHANNEL);
2299 pch->file.hdrlen = chan->hdrlen;
2300 #ifdef CONFIG_PPP_MULTILINK
2302 #endif /* CONFIG_PPP_MULTILINK */
2303 init_rwsem(&pch->chan_sem);
2304 spin_lock_init(&pch->downl);
2305 rwlock_init(&pch->upl);
2307 spin_lock_bh(&pn->all_channels_lock);
2308 pch->file.index = ++pn->last_channel_index;
2309 list_add(&pch->list, &pn->new_channels);
2310 atomic_inc(&channel_count);
2311 spin_unlock_bh(&pn->all_channels_lock);
2317 * Return the index of a channel.
2319 int ppp_channel_index(struct ppp_channel *chan)
2321 struct channel *pch = chan->ppp;
2324 return pch->file.index;
2329 * Return the PPP unit number to which a channel is connected.
2331 int ppp_unit_number(struct ppp_channel *chan)
2333 struct channel *pch = chan->ppp;
2337 read_lock_bh(&pch->upl);
2339 unit = pch->ppp->file.index;
2340 read_unlock_bh(&pch->upl);
2346 * Return the PPP device interface name of a channel.
2348 char *ppp_dev_name(struct ppp_channel *chan)
2350 struct channel *pch = chan->ppp;
2354 read_lock_bh(&pch->upl);
2355 if (pch->ppp && pch->ppp->dev)
2356 name = pch->ppp->dev->name;
2357 read_unlock_bh(&pch->upl);
2364 * Disconnect a channel from the generic layer.
2365 * This must be called in process context.
2368 ppp_unregister_channel(struct ppp_channel *chan)
2370 struct channel *pch = chan->ppp;
2374 return; /* should never happen */
2379 * This ensures that we have returned from any calls into the
2380 * the channel's start_xmit or ioctl routine before we proceed.
2382 down_write(&pch->chan_sem);
2383 spin_lock_bh(&pch->downl);
2385 spin_unlock_bh(&pch->downl);
2386 up_write(&pch->chan_sem);
2387 ppp_disconnect_channel(pch);
2389 pn = ppp_pernet(pch->chan_net);
2390 spin_lock_bh(&pn->all_channels_lock);
2391 list_del(&pch->list);
2392 spin_unlock_bh(&pn->all_channels_lock);
2395 wake_up_interruptible(&pch->file.rwait);
2396 if (atomic_dec_and_test(&pch->file.refcnt))
2397 ppp_destroy_channel(pch);
2401 * Callback from a channel when it can accept more to transmit.
2402 * This should be called at BH/softirq level, not interrupt level.
2405 ppp_output_wakeup(struct ppp_channel *chan)
2407 struct channel *pch = chan->ppp;
2411 ppp_channel_push(pch);
2415 * Compression control.
2418 /* Process the PPPIOCSCOMPRESS ioctl. */
2420 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2423 struct compressor *cp, *ocomp;
2424 struct ppp_option_data data;
2425 void *state, *ostate;
2426 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2429 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2430 (data.length <= CCP_MAX_OPTION_LENGTH &&
2431 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2434 if (data.length > CCP_MAX_OPTION_LENGTH ||
2435 ccp_option[1] < 2 || ccp_option[1] > data.length)
2438 cp = try_then_request_module(
2439 find_compressor(ccp_option[0]),
2440 "ppp-compress-%d", ccp_option[0]);
2445 if (data.transmit) {
2446 state = cp->comp_alloc(ccp_option, data.length);
2449 ppp->xstate &= ~SC_COMP_RUN;
2451 ostate = ppp->xc_state;
2453 ppp->xc_state = state;
2454 ppp_xmit_unlock(ppp);
2456 ocomp->comp_free(ostate);
2457 module_put(ocomp->owner);
2461 module_put(cp->owner);
2464 state = cp->decomp_alloc(ccp_option, data.length);
2467 ppp->rstate &= ~SC_DECOMP_RUN;
2469 ostate = ppp->rc_state;
2471 ppp->rc_state = state;
2472 ppp_recv_unlock(ppp);
2474 ocomp->decomp_free(ostate);
2475 module_put(ocomp->owner);
2479 module_put(cp->owner);
2487 * Look at a CCP packet and update our state accordingly.
2488 * We assume the caller has the xmit or recv path locked.
2491 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2496 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2497 return; /* no header */
2500 switch (CCP_CODE(dp)) {
2503 /* A ConfReq starts negotiation of compression
2504 * in one direction of transmission,
2505 * and hence brings it down...but which way?
2508 * A ConfReq indicates what the sender would like to receive
2511 /* He is proposing what I should send */
2512 ppp->xstate &= ~SC_COMP_RUN;
2514 /* I am proposing to what he should send */
2515 ppp->rstate &= ~SC_DECOMP_RUN;
2522 * CCP is going down, both directions of transmission
2524 ppp->rstate &= ~SC_DECOMP_RUN;
2525 ppp->xstate &= ~SC_COMP_RUN;
2529 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2531 len = CCP_LENGTH(dp);
2532 if (!pskb_may_pull(skb, len + 2))
2533 return; /* too short */
2536 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2539 /* we will start receiving compressed packets */
2542 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2543 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2544 ppp->rstate |= SC_DECOMP_RUN;
2545 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2548 /* we will soon start sending compressed packets */
2551 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2552 ppp->file.index, 0, ppp->debug))
2553 ppp->xstate |= SC_COMP_RUN;
2558 /* reset the [de]compressor */
2559 if ((ppp->flags & SC_CCP_UP) == 0)
2562 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2563 ppp->rcomp->decomp_reset(ppp->rc_state);
2564 ppp->rstate &= ~SC_DC_ERROR;
2567 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2568 ppp->xcomp->comp_reset(ppp->xc_state);
2574 /* Free up compression resources. */
2576 ppp_ccp_closed(struct ppp *ppp)
2578 void *xstate, *rstate;
2579 struct compressor *xcomp, *rcomp;
2582 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2585 xstate = ppp->xc_state;
2586 ppp->xc_state = NULL;
2589 rstate = ppp->rc_state;
2590 ppp->rc_state = NULL;
2594 xcomp->comp_free(xstate);
2595 module_put(xcomp->owner);
2598 rcomp->decomp_free(rstate);
2599 module_put(rcomp->owner);
2603 /* List of compressors. */
2604 static LIST_HEAD(compressor_list);
2605 static DEFINE_SPINLOCK(compressor_list_lock);
2607 struct compressor_entry {
2608 struct list_head list;
2609 struct compressor *comp;
2612 static struct compressor_entry *
2613 find_comp_entry(int proto)
2615 struct compressor_entry *ce;
2617 list_for_each_entry(ce, &compressor_list, list) {
2618 if (ce->comp->compress_proto == proto)
2624 /* Register a compressor */
2626 ppp_register_compressor(struct compressor *cp)
2628 struct compressor_entry *ce;
2630 spin_lock(&compressor_list_lock);
2632 if (find_comp_entry(cp->compress_proto))
2635 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2640 list_add(&ce->list, &compressor_list);
2642 spin_unlock(&compressor_list_lock);
2646 /* Unregister a compressor */
2648 ppp_unregister_compressor(struct compressor *cp)
2650 struct compressor_entry *ce;
2652 spin_lock(&compressor_list_lock);
2653 ce = find_comp_entry(cp->compress_proto);
2654 if (ce && ce->comp == cp) {
2655 list_del(&ce->list);
2658 spin_unlock(&compressor_list_lock);
2661 /* Find a compressor. */
2662 static struct compressor *
2663 find_compressor(int type)
2665 struct compressor_entry *ce;
2666 struct compressor *cp = NULL;
2668 spin_lock(&compressor_list_lock);
2669 ce = find_comp_entry(type);
2672 if (!try_module_get(cp->owner))
2675 spin_unlock(&compressor_list_lock);
2680 * Miscelleneous stuff.
2684 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2686 struct slcompress *vj = ppp->vj;
2688 memset(st, 0, sizeof(*st));
2689 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2690 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2691 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2692 st->p.ppp_opackets = ppp->stats64.tx_packets;
2693 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2694 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2697 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2698 st->vj.vjs_compressed = vj->sls_o_compressed;
2699 st->vj.vjs_searches = vj->sls_o_searches;
2700 st->vj.vjs_misses = vj->sls_o_misses;
2701 st->vj.vjs_errorin = vj->sls_i_error;
2702 st->vj.vjs_tossed = vj->sls_i_tossed;
2703 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2704 st->vj.vjs_compressedin = vj->sls_i_compressed;
2708 * Stuff for handling the lists of ppp units and channels
2709 * and for initialization.
2713 * Create a new ppp interface unit. Fails if it can't allocate memory
2714 * or if there is already a unit with the requested number.
2715 * unit == -1 means allocate a new number.
2717 static struct ppp *ppp_create_interface(struct net *net, int unit,
2718 struct file *file, int *retp)
2722 struct net_device *dev = NULL;
2726 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN,
2731 pn = ppp_pernet(net);
2733 ppp = netdev_priv(dev);
2736 init_ppp_file(&ppp->file, INTERFACE);
2737 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2739 for (i = 0; i < NUM_NP; ++i)
2740 ppp->npmode[i] = NPMODE_PASS;
2741 INIT_LIST_HEAD(&ppp->channels);
2742 spin_lock_init(&ppp->rlock);
2743 spin_lock_init(&ppp->wlock);
2744 #ifdef CONFIG_PPP_MULTILINK
2746 skb_queue_head_init(&ppp->mrq);
2747 #endif /* CONFIG_PPP_MULTILINK */
2748 #ifdef CONFIG_PPP_FILTER
2749 ppp->pass_filter = NULL;
2750 ppp->active_filter = NULL;
2751 #endif /* CONFIG_PPP_FILTER */
2754 * drum roll: don't forget to set
2755 * the net device is belong to
2757 dev_net_set(dev, net);
2760 mutex_lock(&pn->all_ppp_mutex);
2763 unit = unit_get(&pn->units_idr, ppp);
2770 if (unit_find(&pn->units_idr, unit))
2771 goto out2; /* unit already exists */
2773 * if caller need a specified unit number
2774 * lets try to satisfy him, otherwise --
2775 * he should better ask us for new unit number
2777 * NOTE: yes I know that returning EEXIST it's not
2778 * fair but at least pppd will ask us to allocate
2779 * new unit in this case so user is happy :)
2781 unit = unit_set(&pn->units_idr, ppp, unit);
2786 /* Initialize the new ppp unit */
2787 ppp->file.index = unit;
2788 sprintf(dev->name, "ppp%d", unit);
2790 ret = register_netdevice(dev);
2792 unit_put(&pn->units_idr, unit);
2793 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2800 atomic_inc(&ppp_unit_count);
2801 mutex_unlock(&pn->all_ppp_mutex);
2808 mutex_unlock(&pn->all_ppp_mutex);
2817 * Initialize a ppp_file structure.
2820 init_ppp_file(struct ppp_file *pf, int kind)
2823 skb_queue_head_init(&pf->xq);
2824 skb_queue_head_init(&pf->rq);
2825 atomic_set(&pf->refcnt, 1);
2826 init_waitqueue_head(&pf->rwait);
2830 * Free the memory used by a ppp unit. This is only called once
2831 * there are no channels connected to the unit and no file structs
2832 * that reference the unit.
2834 static void ppp_destroy_interface(struct ppp *ppp)
2836 atomic_dec(&ppp_unit_count);
2838 if (!ppp->file.dead || ppp->n_channels) {
2839 /* "can't happen" */
2840 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2841 "but dead=%d n_channels=%d !\n",
2842 ppp, ppp->file.dead, ppp->n_channels);
2846 ppp_ccp_closed(ppp);
2851 skb_queue_purge(&ppp->file.xq);
2852 skb_queue_purge(&ppp->file.rq);
2853 #ifdef CONFIG_PPP_MULTILINK
2854 skb_queue_purge(&ppp->mrq);
2855 #endif /* CONFIG_PPP_MULTILINK */
2856 #ifdef CONFIG_PPP_FILTER
2857 if (ppp->pass_filter) {
2858 bpf_prog_destroy(ppp->pass_filter);
2859 ppp->pass_filter = NULL;
2862 if (ppp->active_filter) {
2863 bpf_prog_destroy(ppp->active_filter);
2864 ppp->active_filter = NULL;
2866 #endif /* CONFIG_PPP_FILTER */
2868 kfree_skb(ppp->xmit_pending);
2870 free_netdev(ppp->dev);
2874 * Locate an existing ppp unit.
2875 * The caller should have locked the all_ppp_mutex.
2878 ppp_find_unit(struct ppp_net *pn, int unit)
2880 return unit_find(&pn->units_idr, unit);
2884 * Locate an existing ppp channel.
2885 * The caller should have locked the all_channels_lock.
2886 * First we look in the new_channels list, then in the
2887 * all_channels list. If found in the new_channels list,
2888 * we move it to the all_channels list. This is for speed
2889 * when we have a lot of channels in use.
2891 static struct channel *
2892 ppp_find_channel(struct ppp_net *pn, int unit)
2894 struct channel *pch;
2896 list_for_each_entry(pch, &pn->new_channels, list) {
2897 if (pch->file.index == unit) {
2898 list_move(&pch->list, &pn->all_channels);
2903 list_for_each_entry(pch, &pn->all_channels, list) {
2904 if (pch->file.index == unit)
2912 * Connect a PPP channel to a PPP interface unit.
2915 ppp_connect_channel(struct channel *pch, int unit)
2922 pn = ppp_pernet(pch->chan_net);
2924 mutex_lock(&pn->all_ppp_mutex);
2925 ppp = ppp_find_unit(pn, unit);
2928 write_lock_bh(&pch->upl);
2934 if (pch->file.hdrlen > ppp->file.hdrlen)
2935 ppp->file.hdrlen = pch->file.hdrlen;
2936 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2937 if (hdrlen > ppp->dev->hard_header_len)
2938 ppp->dev->hard_header_len = hdrlen;
2939 list_add_tail(&pch->clist, &ppp->channels);
2942 atomic_inc(&ppp->file.refcnt);
2947 write_unlock_bh(&pch->upl);
2949 mutex_unlock(&pn->all_ppp_mutex);
2954 * Disconnect a channel from its ppp unit.
2957 ppp_disconnect_channel(struct channel *pch)
2962 write_lock_bh(&pch->upl);
2965 write_unlock_bh(&pch->upl);
2967 /* remove it from the ppp unit's list */
2969 list_del(&pch->clist);
2970 if (--ppp->n_channels == 0)
2971 wake_up_interruptible(&ppp->file.rwait);
2973 if (atomic_dec_and_test(&ppp->file.refcnt))
2974 ppp_destroy_interface(ppp);
2981 * Free up the resources used by a ppp channel.
2983 static void ppp_destroy_channel(struct channel *pch)
2985 put_net(pch->chan_net);
2986 pch->chan_net = NULL;
2988 atomic_dec(&channel_count);
2990 if (!pch->file.dead) {
2991 /* "can't happen" */
2992 pr_err("ppp: destroying undead channel %p !\n", pch);
2995 skb_queue_purge(&pch->file.xq);
2996 skb_queue_purge(&pch->file.rq);
3000 static void __exit ppp_cleanup(void)
3002 /* should never happen */
3003 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3004 pr_err("PPP: removing module but units remain!\n");
3005 unregister_chrdev(PPP_MAJOR, "ppp");
3006 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3007 class_destroy(ppp_class);
3008 unregister_pernet_device(&ppp_net_ops);
3012 * Units handling. Caller must protect concurrent access
3013 * by holding all_ppp_mutex
3016 /* associate pointer with specified number */
3017 static int unit_set(struct idr *p, void *ptr, int n)
3021 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3022 if (unit == -ENOSPC)
3027 /* get new free unit number and associate pointer with it */
3028 static int unit_get(struct idr *p, void *ptr)
3030 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3033 /* put unit number back to a pool */
3034 static void unit_put(struct idr *p, int n)
3039 /* get pointer associated with the number */
3040 static void *unit_find(struct idr *p, int n)
3042 return idr_find(p, n);
3045 /* Module/initialization stuff */
3047 module_init(ppp_init);
3048 module_exit(ppp_cleanup);
3050 EXPORT_SYMBOL(ppp_register_net_channel);
3051 EXPORT_SYMBOL(ppp_register_channel);
3052 EXPORT_SYMBOL(ppp_unregister_channel);
3053 EXPORT_SYMBOL(ppp_channel_index);
3054 EXPORT_SYMBOL(ppp_unit_number);
3055 EXPORT_SYMBOL(ppp_dev_name);
3056 EXPORT_SYMBOL(ppp_input);
3057 EXPORT_SYMBOL(ppp_input_error);
3058 EXPORT_SYMBOL(ppp_output_wakeup);
3059 EXPORT_SYMBOL(ppp_register_compressor);
3060 EXPORT_SYMBOL(ppp_unregister_compressor);
3061 MODULE_LICENSE("GPL");
3062 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3063 MODULE_ALIAS("devname:ppp");