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 mutex_destroy(&pn->all_ppp_mutex);
946 idr_destroy(&pn->units_idr);
949 static struct pernet_operations ppp_net_ops = {
950 .init = ppp_init_net,
951 .exit = ppp_exit_net,
953 .size = sizeof(struct ppp_net),
956 #define PPP_MAJOR 108
958 /* Called at boot time if ppp is compiled into the kernel,
959 or at module load time (from init_module) if compiled as a module. */
960 static int __init ppp_init(void)
964 pr_info("PPP generic driver version " PPP_VERSION "\n");
966 err = register_pernet_device(&ppp_net_ops);
968 pr_err("failed to register PPP pernet device (%d)\n", err);
972 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
974 pr_err("failed to register PPP device (%d)\n", err);
978 ppp_class = class_create(THIS_MODULE, "ppp");
979 if (IS_ERR(ppp_class)) {
980 err = PTR_ERR(ppp_class);
984 /* not a big deal if we fail here :-) */
985 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
990 unregister_chrdev(PPP_MAJOR, "ppp");
992 unregister_pernet_device(&ppp_net_ops);
998 * Network interface unit routines.
1001 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1003 struct ppp *ppp = netdev_priv(dev);
1007 npi = ethertype_to_npindex(ntohs(skb->protocol));
1011 /* Drop, accept or reject the packet */
1012 switch (ppp->npmode[npi]) {
1016 /* it would be nice to have a way to tell the network
1017 system to queue this one up for later. */
1024 /* Put the 2-byte PPP protocol number on the front,
1025 making sure there is room for the address and control fields. */
1026 if (skb_cow_head(skb, PPP_HDRLEN))
1029 pp = skb_push(skb, 2);
1030 proto = npindex_to_proto[npi];
1031 put_unaligned_be16(proto, pp);
1033 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1034 skb_queue_tail(&ppp->file.xq, skb);
1035 ppp_xmit_process(ppp);
1036 return NETDEV_TX_OK;
1040 ++dev->stats.tx_dropped;
1041 return NETDEV_TX_OK;
1045 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1047 struct ppp *ppp = netdev_priv(dev);
1049 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1050 struct ppp_stats stats;
1051 struct ppp_comp_stats cstats;
1056 ppp_get_stats(ppp, &stats);
1057 if (copy_to_user(addr, &stats, sizeof(stats)))
1062 case SIOCGPPPCSTATS:
1063 memset(&cstats, 0, sizeof(cstats));
1065 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1067 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1068 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1075 if (copy_to_user(addr, vers, strlen(vers) + 1))
1087 static struct rtnl_link_stats64*
1088 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1090 struct ppp *ppp = netdev_priv(dev);
1093 stats64->rx_packets = ppp->stats64.rx_packets;
1094 stats64->rx_bytes = ppp->stats64.rx_bytes;
1095 ppp_recv_unlock(ppp);
1098 stats64->tx_packets = ppp->stats64.tx_packets;
1099 stats64->tx_bytes = ppp->stats64.tx_bytes;
1100 ppp_xmit_unlock(ppp);
1102 stats64->rx_errors = dev->stats.rx_errors;
1103 stats64->tx_errors = dev->stats.tx_errors;
1104 stats64->rx_dropped = dev->stats.rx_dropped;
1105 stats64->tx_dropped = dev->stats.tx_dropped;
1106 stats64->rx_length_errors = dev->stats.rx_length_errors;
1111 static struct lock_class_key ppp_tx_busylock;
1112 static int ppp_dev_init(struct net_device *dev)
1116 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1118 ppp = netdev_priv(dev);
1119 /* Let the netdevice take a reference on the ppp file. This ensures
1120 * that ppp_destroy_interface() won't run before the device gets
1123 atomic_inc(&ppp->file.refcnt);
1128 static void ppp_dev_uninit(struct net_device *dev)
1130 struct ppp *ppp = netdev_priv(dev);
1131 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1137 mutex_lock(&pn->all_ppp_mutex);
1138 unit_put(&pn->units_idr, ppp->file.index);
1139 mutex_unlock(&pn->all_ppp_mutex);
1144 wake_up_interruptible(&ppp->file.rwait);
1147 static void ppp_dev_priv_destructor(struct net_device *dev)
1151 ppp = netdev_priv(dev);
1152 if (atomic_dec_and_test(&ppp->file.refcnt))
1153 ppp_destroy_interface(ppp);
1156 static const struct net_device_ops ppp_netdev_ops = {
1157 .ndo_init = ppp_dev_init,
1158 .ndo_uninit = ppp_dev_uninit,
1159 .ndo_start_xmit = ppp_start_xmit,
1160 .ndo_do_ioctl = ppp_net_ioctl,
1161 .ndo_get_stats64 = ppp_get_stats64,
1164 static void ppp_setup(struct net_device *dev)
1166 dev->netdev_ops = &ppp_netdev_ops;
1167 dev->hard_header_len = PPP_HDRLEN;
1170 dev->tx_queue_len = 3;
1171 dev->type = ARPHRD_PPP;
1172 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1173 dev->destructor = ppp_dev_priv_destructor;
1174 netif_keep_dst(dev);
1178 * Transmit-side routines.
1182 * Called to do any work queued up on the transmit side
1183 * that can now be done.
1186 ppp_xmit_process(struct ppp *ppp)
1188 struct sk_buff *skb;
1191 if (!ppp->closing) {
1193 while (!ppp->xmit_pending &&
1194 (skb = skb_dequeue(&ppp->file.xq)))
1195 ppp_send_frame(ppp, skb);
1196 /* If there's no work left to do, tell the core net
1197 code that we can accept some more. */
1198 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1199 netif_wake_queue(ppp->dev);
1201 netif_stop_queue(ppp->dev);
1203 ppp_xmit_unlock(ppp);
1206 static inline struct sk_buff *
1207 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1209 struct sk_buff *new_skb;
1211 int new_skb_size = ppp->dev->mtu +
1212 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1213 int compressor_skb_size = ppp->dev->mtu +
1214 ppp->xcomp->comp_extra + PPP_HDRLEN;
1215 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1217 if (net_ratelimit())
1218 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1221 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1222 skb_reserve(new_skb,
1223 ppp->dev->hard_header_len - PPP_HDRLEN);
1225 /* compressor still expects A/C bytes in hdr */
1226 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1227 new_skb->data, skb->len + 2,
1228 compressor_skb_size);
1229 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1233 skb_pull(skb, 2); /* pull off A/C bytes */
1234 } else if (len == 0) {
1235 /* didn't compress, or CCP not up yet */
1236 consume_skb(new_skb);
1241 * MPPE requires that we do not send unencrypted
1242 * frames. The compressor will return -1 if we
1243 * should drop the frame. We cannot simply test
1244 * the compress_proto because MPPE and MPPC share
1247 if (net_ratelimit())
1248 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1250 consume_skb(new_skb);
1257 * Compress and send a frame.
1258 * The caller should have locked the xmit path,
1259 * and xmit_pending should be 0.
1262 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1264 int proto = PPP_PROTO(skb);
1265 struct sk_buff *new_skb;
1269 if (proto < 0x8000) {
1270 #ifdef CONFIG_PPP_FILTER
1271 /* check if we should pass this packet */
1272 /* the filter instructions are constructed assuming
1273 a four-byte PPP header on each packet */
1274 *skb_push(skb, 2) = 1;
1275 if (ppp->pass_filter &&
1276 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1278 netdev_printk(KERN_DEBUG, ppp->dev,
1279 "PPP: outbound frame "
1284 /* if this packet passes the active filter, record the time */
1285 if (!(ppp->active_filter &&
1286 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1287 ppp->last_xmit = jiffies;
1290 /* for data packets, record the time */
1291 ppp->last_xmit = jiffies;
1292 #endif /* CONFIG_PPP_FILTER */
1295 ++ppp->stats64.tx_packets;
1296 ppp->stats64.tx_bytes += skb->len - 2;
1300 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1302 /* try to do VJ TCP header compression */
1303 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1306 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1309 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1311 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1312 new_skb->data + 2, &cp,
1313 !(ppp->flags & SC_NO_TCP_CCID));
1314 if (cp == skb->data + 2) {
1315 /* didn't compress */
1316 consume_skb(new_skb);
1318 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1319 proto = PPP_VJC_COMP;
1320 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1322 proto = PPP_VJC_UNCOMP;
1323 cp[0] = skb->data[2];
1327 cp = skb_put(skb, len + 2);
1334 /* peek at outbound CCP frames */
1335 ppp_ccp_peek(ppp, skb, 0);
1339 /* try to do packet compression */
1340 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1341 proto != PPP_LCP && proto != PPP_CCP) {
1342 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1343 if (net_ratelimit())
1344 netdev_err(ppp->dev,
1345 "ppp: compression required but "
1346 "down - pkt dropped.\n");
1349 skb = pad_compress_skb(ppp, skb);
1355 * If we are waiting for traffic (demand dialling),
1356 * queue it up for pppd to receive.
1358 if (ppp->flags & SC_LOOP_TRAFFIC) {
1359 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1361 skb_queue_tail(&ppp->file.rq, skb);
1362 wake_up_interruptible(&ppp->file.rwait);
1366 ppp->xmit_pending = skb;
1372 ++ppp->dev->stats.tx_errors;
1376 * Try to send the frame in xmit_pending.
1377 * The caller should have the xmit path locked.
1380 ppp_push(struct ppp *ppp)
1382 struct list_head *list;
1383 struct channel *pch;
1384 struct sk_buff *skb = ppp->xmit_pending;
1389 list = &ppp->channels;
1390 if (list_empty(list)) {
1391 /* nowhere to send the packet, just drop it */
1392 ppp->xmit_pending = NULL;
1397 if ((ppp->flags & SC_MULTILINK) == 0) {
1398 /* not doing multilink: send it down the first channel */
1400 pch = list_entry(list, struct channel, clist);
1402 spin_lock_bh(&pch->downl);
1404 if (pch->chan->ops->start_xmit(pch->chan, skb))
1405 ppp->xmit_pending = NULL;
1407 /* channel got unregistered */
1409 ppp->xmit_pending = NULL;
1411 spin_unlock_bh(&pch->downl);
1415 #ifdef CONFIG_PPP_MULTILINK
1416 /* Multilink: fragment the packet over as many links
1417 as can take the packet at the moment. */
1418 if (!ppp_mp_explode(ppp, skb))
1420 #endif /* CONFIG_PPP_MULTILINK */
1422 ppp->xmit_pending = NULL;
1426 #ifdef CONFIG_PPP_MULTILINK
1427 static bool mp_protocol_compress __read_mostly = true;
1428 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1429 MODULE_PARM_DESC(mp_protocol_compress,
1430 "compress protocol id in multilink fragments");
1433 * Divide a packet to be transmitted into fragments and
1434 * send them out the individual links.
1436 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1439 int i, bits, hdrlen, mtu;
1441 int navail, nfree, nzero;
1445 unsigned char *p, *q;
1446 struct list_head *list;
1447 struct channel *pch;
1448 struct sk_buff *frag;
1449 struct ppp_channel *chan;
1451 totspeed = 0; /*total bitrate of the bundle*/
1452 nfree = 0; /* # channels which have no packet already queued */
1453 navail = 0; /* total # of usable channels (not deregistered) */
1454 nzero = 0; /* number of channels with zero speed associated*/
1455 totfree = 0; /*total # of channels available and
1456 *having no queued packets before
1457 *starting the fragmentation*/
1459 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1461 list_for_each_entry(pch, &ppp->channels, clist) {
1465 pch->speed = pch->chan->speed;
1470 if (skb_queue_empty(&pch->file.xq) ||
1472 if (pch->speed == 0)
1475 totspeed += pch->speed;
1481 if (!pch->had_frag && i < ppp->nxchan)
1487 * Don't start sending this packet unless at least half of
1488 * the channels are free. This gives much better TCP
1489 * performance if we have a lot of channels.
1491 if (nfree == 0 || nfree < navail / 2)
1492 return 0; /* can't take now, leave it in xmit_pending */
1494 /* Do protocol field compression */
1497 if (*p == 0 && mp_protocol_compress) {
1503 nbigger = len % nfree;
1505 /* skip to the channel after the one we last used
1506 and start at that one */
1507 list = &ppp->channels;
1508 for (i = 0; i < ppp->nxchan; ++i) {
1510 if (list == &ppp->channels) {
1516 /* create a fragment for each channel */
1520 if (list == &ppp->channels) {
1524 pch = list_entry(list, struct channel, clist);
1530 * Skip this channel if it has a fragment pending already and
1531 * we haven't given a fragment to all of the free channels.
1533 if (pch->avail == 1) {
1540 /* check the channel's mtu and whether it is still attached. */
1541 spin_lock_bh(&pch->downl);
1542 if (pch->chan == NULL) {
1543 /* can't use this channel, it's being deregistered */
1544 if (pch->speed == 0)
1547 totspeed -= pch->speed;
1549 spin_unlock_bh(&pch->downl);
1560 *if the channel speed is not set divide
1561 *the packet evenly among the free channels;
1562 *otherwise divide it according to the speed
1563 *of the channel we are going to transmit on
1567 if (pch->speed == 0) {
1574 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1575 ((totspeed*totfree)/pch->speed)) - hdrlen;
1577 flen += ((totfree - nzero)*pch->speed)/totspeed;
1578 nbigger -= ((totfree - nzero)*pch->speed)/
1586 *check if we are on the last channel or
1587 *we exceded the length of the data to
1590 if ((nfree <= 0) || (flen > len))
1593 *it is not worth to tx on slow channels:
1594 *in that case from the resulting flen according to the
1595 *above formula will be equal or less than zero.
1596 *Skip the channel in this case
1600 spin_unlock_bh(&pch->downl);
1605 * hdrlen includes the 2-byte PPP protocol field, but the
1606 * MTU counts only the payload excluding the protocol field.
1607 * (RFC1661 Section 2)
1609 mtu = pch->chan->mtu - (hdrlen - 2);
1616 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1619 q = skb_put(frag, flen + hdrlen);
1621 /* make the MP header */
1622 put_unaligned_be16(PPP_MP, q);
1623 if (ppp->flags & SC_MP_XSHORTSEQ) {
1624 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1628 q[3] = ppp->nxseq >> 16;
1629 q[4] = ppp->nxseq >> 8;
1633 memcpy(q + hdrlen, p, flen);
1635 /* try to send it down the channel */
1637 if (!skb_queue_empty(&pch->file.xq) ||
1638 !chan->ops->start_xmit(chan, frag))
1639 skb_queue_tail(&pch->file.xq, frag);
1645 spin_unlock_bh(&pch->downl);
1652 spin_unlock_bh(&pch->downl);
1654 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1655 ++ppp->dev->stats.tx_errors;
1657 return 1; /* abandon the frame */
1659 #endif /* CONFIG_PPP_MULTILINK */
1662 * Try to send data out on a channel.
1665 ppp_channel_push(struct channel *pch)
1667 struct sk_buff *skb;
1670 spin_lock_bh(&pch->downl);
1672 while (!skb_queue_empty(&pch->file.xq)) {
1673 skb = skb_dequeue(&pch->file.xq);
1674 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1675 /* put the packet back and try again later */
1676 skb_queue_head(&pch->file.xq, skb);
1681 /* channel got deregistered */
1682 skb_queue_purge(&pch->file.xq);
1684 spin_unlock_bh(&pch->downl);
1685 /* see if there is anything from the attached unit to be sent */
1686 if (skb_queue_empty(&pch->file.xq)) {
1687 read_lock_bh(&pch->upl);
1690 ppp_xmit_process(ppp);
1691 read_unlock_bh(&pch->upl);
1696 * Receive-side routines.
1699 struct ppp_mp_skb_parm {
1703 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1706 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1710 ppp_receive_frame(ppp, skb, pch);
1713 ppp_recv_unlock(ppp);
1717 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1719 struct channel *pch = chan->ppp;
1727 read_lock_bh(&pch->upl);
1728 if (!pskb_may_pull(skb, 2)) {
1731 ++pch->ppp->dev->stats.rx_length_errors;
1732 ppp_receive_error(pch->ppp);
1737 proto = PPP_PROTO(skb);
1738 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1739 /* put it on the channel queue */
1740 skb_queue_tail(&pch->file.rq, skb);
1741 /* drop old frames if queue too long */
1742 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1743 (skb = skb_dequeue(&pch->file.rq)))
1745 wake_up_interruptible(&pch->file.rwait);
1747 ppp_do_recv(pch->ppp, skb, pch);
1751 read_unlock_bh(&pch->upl);
1754 /* Put a 0-length skb in the receive queue as an error indication */
1756 ppp_input_error(struct ppp_channel *chan, int code)
1758 struct channel *pch = chan->ppp;
1759 struct sk_buff *skb;
1764 read_lock_bh(&pch->upl);
1766 skb = alloc_skb(0, GFP_ATOMIC);
1768 skb->len = 0; /* probably unnecessary */
1770 ppp_do_recv(pch->ppp, skb, pch);
1773 read_unlock_bh(&pch->upl);
1777 * We come in here to process a received frame.
1778 * The receive side of the ppp unit is locked.
1781 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1783 /* note: a 0-length skb is used as an error indication */
1785 skb_checksum_complete_unset(skb);
1786 #ifdef CONFIG_PPP_MULTILINK
1787 /* XXX do channel-level decompression here */
1788 if (PPP_PROTO(skb) == PPP_MP)
1789 ppp_receive_mp_frame(ppp, skb, pch);
1791 #endif /* CONFIG_PPP_MULTILINK */
1792 ppp_receive_nonmp_frame(ppp, skb);
1795 ppp_receive_error(ppp);
1800 ppp_receive_error(struct ppp *ppp)
1802 ++ppp->dev->stats.rx_errors;
1808 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1811 int proto, len, npi;
1814 * Decompress the frame, if compressed.
1815 * Note that some decompressors need to see uncompressed frames
1816 * that come in as well as compressed frames.
1818 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1819 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1820 skb = ppp_decompress_frame(ppp, skb);
1822 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1825 proto = PPP_PROTO(skb);
1828 /* decompress VJ compressed packets */
1829 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1832 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1833 /* copy to a new sk_buff with more tailroom */
1834 ns = dev_alloc_skb(skb->len + 128);
1836 netdev_err(ppp->dev, "PPP: no memory "
1841 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1846 skb->ip_summed = CHECKSUM_NONE;
1848 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1850 netdev_printk(KERN_DEBUG, ppp->dev,
1851 "PPP: VJ decompression error\n");
1856 skb_put(skb, len - skb->len);
1857 else if (len < skb->len)
1862 case PPP_VJC_UNCOMP:
1863 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1866 /* Until we fix the decompressor need to make sure
1867 * data portion is linear.
1869 if (!pskb_may_pull(skb, skb->len))
1872 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1873 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1880 ppp_ccp_peek(ppp, skb, 1);
1884 ++ppp->stats64.rx_packets;
1885 ppp->stats64.rx_bytes += skb->len - 2;
1887 npi = proto_to_npindex(proto);
1889 /* control or unknown frame - pass it to pppd */
1890 skb_queue_tail(&ppp->file.rq, skb);
1891 /* limit queue length by dropping old frames */
1892 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1893 (skb = skb_dequeue(&ppp->file.rq)))
1895 /* wake up any process polling or blocking on read */
1896 wake_up_interruptible(&ppp->file.rwait);
1899 /* network protocol frame - give it to the kernel */
1901 #ifdef CONFIG_PPP_FILTER
1902 /* check if the packet passes the pass and active filters */
1903 /* the filter instructions are constructed assuming
1904 a four-byte PPP header on each packet */
1905 if (ppp->pass_filter || ppp->active_filter) {
1906 if (skb_unclone(skb, GFP_ATOMIC))
1909 *skb_push(skb, 2) = 0;
1910 if (ppp->pass_filter &&
1911 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1913 netdev_printk(KERN_DEBUG, ppp->dev,
1914 "PPP: inbound frame "
1919 if (!(ppp->active_filter &&
1920 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1921 ppp->last_recv = jiffies;
1924 #endif /* CONFIG_PPP_FILTER */
1925 ppp->last_recv = jiffies;
1927 if ((ppp->dev->flags & IFF_UP) == 0 ||
1928 ppp->npmode[npi] != NPMODE_PASS) {
1931 /* chop off protocol */
1932 skb_pull_rcsum(skb, 2);
1933 skb->dev = ppp->dev;
1934 skb->protocol = htons(npindex_to_ethertype[npi]);
1935 skb_reset_mac_header(skb);
1936 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
1937 dev_net(ppp->dev)));
1945 ppp_receive_error(ppp);
1948 static struct sk_buff *
1949 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1951 int proto = PPP_PROTO(skb);
1955 /* Until we fix all the decompressor's need to make sure
1956 * data portion is linear.
1958 if (!pskb_may_pull(skb, skb->len))
1961 if (proto == PPP_COMP) {
1964 switch(ppp->rcomp->compress_proto) {
1966 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1969 obuff_size = ppp->mru + PPP_HDRLEN;
1973 ns = dev_alloc_skb(obuff_size);
1975 netdev_err(ppp->dev, "ppp_decompress_frame: "
1979 /* the decompressor still expects the A/C bytes in the hdr */
1980 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1981 skb->len + 2, ns->data, obuff_size);
1983 /* Pass the compressed frame to pppd as an
1984 error indication. */
1985 if (len == DECOMP_FATALERROR)
1986 ppp->rstate |= SC_DC_FERROR;
1994 skb_pull(skb, 2); /* pull off the A/C bytes */
1997 /* Uncompressed frame - pass to decompressor so it
1998 can update its dictionary if necessary. */
1999 if (ppp->rcomp->incomp)
2000 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2007 ppp->rstate |= SC_DC_ERROR;
2008 ppp_receive_error(ppp);
2012 #ifdef CONFIG_PPP_MULTILINK
2014 * Receive a multilink frame.
2015 * We put it on the reconstruction queue and then pull off
2016 * as many completed frames as we can.
2019 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2023 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2025 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2026 goto err; /* no good, throw it away */
2028 /* Decode sequence number and begin/end bits */
2029 if (ppp->flags & SC_MP_SHORTSEQ) {
2030 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2033 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2036 PPP_MP_CB(skb)->BEbits = skb->data[2];
2037 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2040 * Do protocol ID decompression on the first fragment of each packet.
2042 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2043 *skb_push(skb, 1) = 0;
2046 * Expand sequence number to 32 bits, making it as close
2047 * as possible to ppp->minseq.
2049 seq |= ppp->minseq & ~mask;
2050 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2052 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2053 seq -= mask + 1; /* should never happen */
2054 PPP_MP_CB(skb)->sequence = seq;
2058 * If this packet comes before the next one we were expecting,
2061 if (seq_before(seq, ppp->nextseq)) {
2063 ++ppp->dev->stats.rx_dropped;
2064 ppp_receive_error(ppp);
2069 * Reevaluate minseq, the minimum over all channels of the
2070 * last sequence number received on each channel. Because of
2071 * the increasing sequence number rule, we know that any fragment
2072 * before `minseq' which hasn't arrived is never going to arrive.
2073 * The list of channels can't change because we have the receive
2074 * side of the ppp unit locked.
2076 list_for_each_entry(ch, &ppp->channels, clist) {
2077 if (seq_before(ch->lastseq, seq))
2080 if (seq_before(ppp->minseq, seq))
2083 /* Put the fragment on the reconstruction queue */
2084 ppp_mp_insert(ppp, skb);
2086 /* If the queue is getting long, don't wait any longer for packets
2087 before the start of the queue. */
2088 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2089 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2090 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2091 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2094 /* Pull completed packets off the queue and receive them. */
2095 while ((skb = ppp_mp_reconstruct(ppp))) {
2096 if (pskb_may_pull(skb, 2))
2097 ppp_receive_nonmp_frame(ppp, skb);
2099 ++ppp->dev->stats.rx_length_errors;
2101 ppp_receive_error(ppp);
2109 ppp_receive_error(ppp);
2113 * Insert a fragment on the MP reconstruction queue.
2114 * The queue is ordered by increasing sequence number.
2117 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2120 struct sk_buff_head *list = &ppp->mrq;
2121 u32 seq = PPP_MP_CB(skb)->sequence;
2123 /* N.B. we don't need to lock the list lock because we have the
2124 ppp unit receive-side lock. */
2125 skb_queue_walk(list, p) {
2126 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2129 __skb_queue_before(list, p, skb);
2133 * Reconstruct a packet from the MP fragment queue.
2134 * We go through increasing sequence numbers until we find a
2135 * complete packet, or we get to the sequence number for a fragment
2136 * which hasn't arrived but might still do so.
2138 static struct sk_buff *
2139 ppp_mp_reconstruct(struct ppp *ppp)
2141 u32 seq = ppp->nextseq;
2142 u32 minseq = ppp->minseq;
2143 struct sk_buff_head *list = &ppp->mrq;
2144 struct sk_buff *p, *tmp;
2145 struct sk_buff *head, *tail;
2146 struct sk_buff *skb = NULL;
2147 int lost = 0, len = 0;
2149 if (ppp->mrru == 0) /* do nothing until mrru is set */
2153 skb_queue_walk_safe(list, p, tmp) {
2155 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2156 /* this can't happen, anyway ignore the skb */
2157 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2159 PPP_MP_CB(p)->sequence, seq);
2160 __skb_unlink(p, list);
2164 if (PPP_MP_CB(p)->sequence != seq) {
2166 /* Fragment `seq' is missing. If it is after
2167 minseq, it might arrive later, so stop here. */
2168 if (seq_after(seq, minseq))
2170 /* Fragment `seq' is lost, keep going. */
2173 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2174 minseq + 1: PPP_MP_CB(p)->sequence;
2177 netdev_printk(KERN_DEBUG, ppp->dev,
2178 "lost frag %u..%u\n",
2185 * At this point we know that all the fragments from
2186 * ppp->nextseq to seq are either present or lost.
2187 * Also, there are no complete packets in the queue
2188 * that have no missing fragments and end before this
2192 /* B bit set indicates this fragment starts a packet */
2193 if (PPP_MP_CB(p)->BEbits & B) {
2201 /* Got a complete packet yet? */
2202 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2203 (PPP_MP_CB(head)->BEbits & B)) {
2204 if (len > ppp->mrru + 2) {
2205 ++ppp->dev->stats.rx_length_errors;
2206 netdev_printk(KERN_DEBUG, ppp->dev,
2207 "PPP: reconstructed packet"
2208 " is too long (%d)\n", len);
2213 ppp->nextseq = seq + 1;
2217 * If this is the ending fragment of a packet,
2218 * and we haven't found a complete valid packet yet,
2219 * we can discard up to and including this fragment.
2221 if (PPP_MP_CB(p)->BEbits & E) {
2222 struct sk_buff *tmp2;
2224 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2226 netdev_printk(KERN_DEBUG, ppp->dev,
2227 "discarding frag %u\n",
2228 PPP_MP_CB(p)->sequence);
2229 __skb_unlink(p, list);
2232 head = skb_peek(list);
2239 /* If we have a complete packet, copy it all into one skb. */
2241 /* If we have discarded any fragments,
2242 signal a receive error. */
2243 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2244 skb_queue_walk_safe(list, p, tmp) {
2248 netdev_printk(KERN_DEBUG, ppp->dev,
2249 "discarding frag %u\n",
2250 PPP_MP_CB(p)->sequence);
2251 __skb_unlink(p, list);
2256 netdev_printk(KERN_DEBUG, ppp->dev,
2257 " missed pkts %u..%u\n",
2259 PPP_MP_CB(head)->sequence-1);
2260 ++ppp->dev->stats.rx_dropped;
2261 ppp_receive_error(ppp);
2266 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2267 p = skb_queue_next(list, head);
2268 __skb_unlink(skb, list);
2269 skb_queue_walk_from_safe(list, p, tmp) {
2270 __skb_unlink(p, list);
2276 skb->data_len += p->len;
2277 skb->truesize += p->truesize;
2283 __skb_unlink(skb, list);
2286 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2291 #endif /* CONFIG_PPP_MULTILINK */
2294 * Channel interface.
2297 /* Create a new, unattached ppp channel. */
2298 int ppp_register_channel(struct ppp_channel *chan)
2300 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2303 /* Create a new, unattached ppp channel for specified net. */
2304 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2306 struct channel *pch;
2309 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2313 pn = ppp_pernet(net);
2317 pch->chan_net = get_net(net);
2319 init_ppp_file(&pch->file, CHANNEL);
2320 pch->file.hdrlen = chan->hdrlen;
2321 #ifdef CONFIG_PPP_MULTILINK
2323 #endif /* CONFIG_PPP_MULTILINK */
2324 init_rwsem(&pch->chan_sem);
2325 spin_lock_init(&pch->downl);
2326 rwlock_init(&pch->upl);
2328 spin_lock_bh(&pn->all_channels_lock);
2329 pch->file.index = ++pn->last_channel_index;
2330 list_add(&pch->list, &pn->new_channels);
2331 atomic_inc(&channel_count);
2332 spin_unlock_bh(&pn->all_channels_lock);
2338 * Return the index of a channel.
2340 int ppp_channel_index(struct ppp_channel *chan)
2342 struct channel *pch = chan->ppp;
2345 return pch->file.index;
2350 * Return the PPP unit number to which a channel is connected.
2352 int ppp_unit_number(struct ppp_channel *chan)
2354 struct channel *pch = chan->ppp;
2358 read_lock_bh(&pch->upl);
2360 unit = pch->ppp->file.index;
2361 read_unlock_bh(&pch->upl);
2367 * Return the PPP device interface name of a channel.
2369 char *ppp_dev_name(struct ppp_channel *chan)
2371 struct channel *pch = chan->ppp;
2375 read_lock_bh(&pch->upl);
2376 if (pch->ppp && pch->ppp->dev)
2377 name = pch->ppp->dev->name;
2378 read_unlock_bh(&pch->upl);
2385 * Disconnect a channel from the generic layer.
2386 * This must be called in process context.
2389 ppp_unregister_channel(struct ppp_channel *chan)
2391 struct channel *pch = chan->ppp;
2395 return; /* should never happen */
2400 * This ensures that we have returned from any calls into the
2401 * the channel's start_xmit or ioctl routine before we proceed.
2403 down_write(&pch->chan_sem);
2404 spin_lock_bh(&pch->downl);
2406 spin_unlock_bh(&pch->downl);
2407 up_write(&pch->chan_sem);
2408 ppp_disconnect_channel(pch);
2410 pn = ppp_pernet(pch->chan_net);
2411 spin_lock_bh(&pn->all_channels_lock);
2412 list_del(&pch->list);
2413 spin_unlock_bh(&pn->all_channels_lock);
2416 wake_up_interruptible(&pch->file.rwait);
2417 if (atomic_dec_and_test(&pch->file.refcnt))
2418 ppp_destroy_channel(pch);
2422 * Callback from a channel when it can accept more to transmit.
2423 * This should be called at BH/softirq level, not interrupt level.
2426 ppp_output_wakeup(struct ppp_channel *chan)
2428 struct channel *pch = chan->ppp;
2432 ppp_channel_push(pch);
2436 * Compression control.
2439 /* Process the PPPIOCSCOMPRESS ioctl. */
2441 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2444 struct compressor *cp, *ocomp;
2445 struct ppp_option_data data;
2446 void *state, *ostate;
2447 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2450 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2451 (data.length <= CCP_MAX_OPTION_LENGTH &&
2452 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2455 if (data.length > CCP_MAX_OPTION_LENGTH ||
2456 ccp_option[1] < 2 || ccp_option[1] > data.length)
2459 cp = try_then_request_module(
2460 find_compressor(ccp_option[0]),
2461 "ppp-compress-%d", ccp_option[0]);
2466 if (data.transmit) {
2467 state = cp->comp_alloc(ccp_option, data.length);
2470 ppp->xstate &= ~SC_COMP_RUN;
2472 ostate = ppp->xc_state;
2474 ppp->xc_state = state;
2475 ppp_xmit_unlock(ppp);
2477 ocomp->comp_free(ostate);
2478 module_put(ocomp->owner);
2482 module_put(cp->owner);
2485 state = cp->decomp_alloc(ccp_option, data.length);
2488 ppp->rstate &= ~SC_DECOMP_RUN;
2490 ostate = ppp->rc_state;
2492 ppp->rc_state = state;
2493 ppp_recv_unlock(ppp);
2495 ocomp->decomp_free(ostate);
2496 module_put(ocomp->owner);
2500 module_put(cp->owner);
2508 * Look at a CCP packet and update our state accordingly.
2509 * We assume the caller has the xmit or recv path locked.
2512 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2517 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2518 return; /* no header */
2521 switch (CCP_CODE(dp)) {
2524 /* A ConfReq starts negotiation of compression
2525 * in one direction of transmission,
2526 * and hence brings it down...but which way?
2529 * A ConfReq indicates what the sender would like to receive
2532 /* He is proposing what I should send */
2533 ppp->xstate &= ~SC_COMP_RUN;
2535 /* I am proposing to what he should send */
2536 ppp->rstate &= ~SC_DECOMP_RUN;
2543 * CCP is going down, both directions of transmission
2545 ppp->rstate &= ~SC_DECOMP_RUN;
2546 ppp->xstate &= ~SC_COMP_RUN;
2550 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2552 len = CCP_LENGTH(dp);
2553 if (!pskb_may_pull(skb, len + 2))
2554 return; /* too short */
2557 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2560 /* we will start receiving compressed packets */
2563 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2564 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2565 ppp->rstate |= SC_DECOMP_RUN;
2566 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2569 /* we will soon start sending compressed packets */
2572 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2573 ppp->file.index, 0, ppp->debug))
2574 ppp->xstate |= SC_COMP_RUN;
2579 /* reset the [de]compressor */
2580 if ((ppp->flags & SC_CCP_UP) == 0)
2583 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2584 ppp->rcomp->decomp_reset(ppp->rc_state);
2585 ppp->rstate &= ~SC_DC_ERROR;
2588 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2589 ppp->xcomp->comp_reset(ppp->xc_state);
2595 /* Free up compression resources. */
2597 ppp_ccp_closed(struct ppp *ppp)
2599 void *xstate, *rstate;
2600 struct compressor *xcomp, *rcomp;
2603 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2606 xstate = ppp->xc_state;
2607 ppp->xc_state = NULL;
2610 rstate = ppp->rc_state;
2611 ppp->rc_state = NULL;
2615 xcomp->comp_free(xstate);
2616 module_put(xcomp->owner);
2619 rcomp->decomp_free(rstate);
2620 module_put(rcomp->owner);
2624 /* List of compressors. */
2625 static LIST_HEAD(compressor_list);
2626 static DEFINE_SPINLOCK(compressor_list_lock);
2628 struct compressor_entry {
2629 struct list_head list;
2630 struct compressor *comp;
2633 static struct compressor_entry *
2634 find_comp_entry(int proto)
2636 struct compressor_entry *ce;
2638 list_for_each_entry(ce, &compressor_list, list) {
2639 if (ce->comp->compress_proto == proto)
2645 /* Register a compressor */
2647 ppp_register_compressor(struct compressor *cp)
2649 struct compressor_entry *ce;
2651 spin_lock(&compressor_list_lock);
2653 if (find_comp_entry(cp->compress_proto))
2656 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2661 list_add(&ce->list, &compressor_list);
2663 spin_unlock(&compressor_list_lock);
2667 /* Unregister a compressor */
2669 ppp_unregister_compressor(struct compressor *cp)
2671 struct compressor_entry *ce;
2673 spin_lock(&compressor_list_lock);
2674 ce = find_comp_entry(cp->compress_proto);
2675 if (ce && ce->comp == cp) {
2676 list_del(&ce->list);
2679 spin_unlock(&compressor_list_lock);
2682 /* Find a compressor. */
2683 static struct compressor *
2684 find_compressor(int type)
2686 struct compressor_entry *ce;
2687 struct compressor *cp = NULL;
2689 spin_lock(&compressor_list_lock);
2690 ce = find_comp_entry(type);
2693 if (!try_module_get(cp->owner))
2696 spin_unlock(&compressor_list_lock);
2701 * Miscelleneous stuff.
2705 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2707 struct slcompress *vj = ppp->vj;
2709 memset(st, 0, sizeof(*st));
2710 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2711 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2712 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2713 st->p.ppp_opackets = ppp->stats64.tx_packets;
2714 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2715 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2718 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2719 st->vj.vjs_compressed = vj->sls_o_compressed;
2720 st->vj.vjs_searches = vj->sls_o_searches;
2721 st->vj.vjs_misses = vj->sls_o_misses;
2722 st->vj.vjs_errorin = vj->sls_i_error;
2723 st->vj.vjs_tossed = vj->sls_i_tossed;
2724 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2725 st->vj.vjs_compressedin = vj->sls_i_compressed;
2729 * Stuff for handling the lists of ppp units and channels
2730 * and for initialization.
2734 * Create a new ppp interface unit. Fails if it can't allocate memory
2735 * or if there is already a unit with the requested number.
2736 * unit == -1 means allocate a new number.
2738 static struct ppp *ppp_create_interface(struct net *net, int unit,
2739 struct file *file, int *retp)
2743 struct net_device *dev = NULL;
2747 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN,
2752 pn = ppp_pernet(net);
2754 ppp = netdev_priv(dev);
2757 init_ppp_file(&ppp->file, INTERFACE);
2758 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2760 for (i = 0; i < NUM_NP; ++i)
2761 ppp->npmode[i] = NPMODE_PASS;
2762 INIT_LIST_HEAD(&ppp->channels);
2763 spin_lock_init(&ppp->rlock);
2764 spin_lock_init(&ppp->wlock);
2765 #ifdef CONFIG_PPP_MULTILINK
2767 skb_queue_head_init(&ppp->mrq);
2768 #endif /* CONFIG_PPP_MULTILINK */
2769 #ifdef CONFIG_PPP_FILTER
2770 ppp->pass_filter = NULL;
2771 ppp->active_filter = NULL;
2772 #endif /* CONFIG_PPP_FILTER */
2775 * drum roll: don't forget to set
2776 * the net device is belong to
2778 dev_net_set(dev, net);
2781 mutex_lock(&pn->all_ppp_mutex);
2784 unit = unit_get(&pn->units_idr, ppp);
2791 if (unit_find(&pn->units_idr, unit))
2792 goto out2; /* unit already exists */
2794 * if caller need a specified unit number
2795 * lets try to satisfy him, otherwise --
2796 * he should better ask us for new unit number
2798 * NOTE: yes I know that returning EEXIST it's not
2799 * fair but at least pppd will ask us to allocate
2800 * new unit in this case so user is happy :)
2802 unit = unit_set(&pn->units_idr, ppp, unit);
2807 /* Initialize the new ppp unit */
2808 ppp->file.index = unit;
2809 sprintf(dev->name, "ppp%d", unit);
2811 ret = register_netdevice(dev);
2813 unit_put(&pn->units_idr, unit);
2814 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2821 atomic_inc(&ppp_unit_count);
2822 mutex_unlock(&pn->all_ppp_mutex);
2829 mutex_unlock(&pn->all_ppp_mutex);
2838 * Initialize a ppp_file structure.
2841 init_ppp_file(struct ppp_file *pf, int kind)
2844 skb_queue_head_init(&pf->xq);
2845 skb_queue_head_init(&pf->rq);
2846 atomic_set(&pf->refcnt, 1);
2847 init_waitqueue_head(&pf->rwait);
2851 * Free the memory used by a ppp unit. This is only called once
2852 * there are no channels connected to the unit and no file structs
2853 * that reference the unit.
2855 static void ppp_destroy_interface(struct ppp *ppp)
2857 atomic_dec(&ppp_unit_count);
2859 if (!ppp->file.dead || ppp->n_channels) {
2860 /* "can't happen" */
2861 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2862 "but dead=%d n_channels=%d !\n",
2863 ppp, ppp->file.dead, ppp->n_channels);
2867 ppp_ccp_closed(ppp);
2872 skb_queue_purge(&ppp->file.xq);
2873 skb_queue_purge(&ppp->file.rq);
2874 #ifdef CONFIG_PPP_MULTILINK
2875 skb_queue_purge(&ppp->mrq);
2876 #endif /* CONFIG_PPP_MULTILINK */
2877 #ifdef CONFIG_PPP_FILTER
2878 if (ppp->pass_filter) {
2879 bpf_prog_destroy(ppp->pass_filter);
2880 ppp->pass_filter = NULL;
2883 if (ppp->active_filter) {
2884 bpf_prog_destroy(ppp->active_filter);
2885 ppp->active_filter = NULL;
2887 #endif /* CONFIG_PPP_FILTER */
2889 kfree_skb(ppp->xmit_pending);
2891 free_netdev(ppp->dev);
2895 * Locate an existing ppp unit.
2896 * The caller should have locked the all_ppp_mutex.
2899 ppp_find_unit(struct ppp_net *pn, int unit)
2901 return unit_find(&pn->units_idr, unit);
2905 * Locate an existing ppp channel.
2906 * The caller should have locked the all_channels_lock.
2907 * First we look in the new_channels list, then in the
2908 * all_channels list. If found in the new_channels list,
2909 * we move it to the all_channels list. This is for speed
2910 * when we have a lot of channels in use.
2912 static struct channel *
2913 ppp_find_channel(struct ppp_net *pn, int unit)
2915 struct channel *pch;
2917 list_for_each_entry(pch, &pn->new_channels, list) {
2918 if (pch->file.index == unit) {
2919 list_move(&pch->list, &pn->all_channels);
2924 list_for_each_entry(pch, &pn->all_channels, list) {
2925 if (pch->file.index == unit)
2933 * Connect a PPP channel to a PPP interface unit.
2936 ppp_connect_channel(struct channel *pch, int unit)
2943 pn = ppp_pernet(pch->chan_net);
2945 mutex_lock(&pn->all_ppp_mutex);
2946 ppp = ppp_find_unit(pn, unit);
2949 write_lock_bh(&pch->upl);
2955 spin_lock_bh(&pch->downl);
2957 /* Don't connect unregistered channels */
2958 spin_unlock_bh(&pch->downl);
2963 spin_unlock_bh(&pch->downl);
2964 if (pch->file.hdrlen > ppp->file.hdrlen)
2965 ppp->file.hdrlen = pch->file.hdrlen;
2966 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2967 if (hdrlen > ppp->dev->hard_header_len)
2968 ppp->dev->hard_header_len = hdrlen;
2969 list_add_tail(&pch->clist, &ppp->channels);
2972 atomic_inc(&ppp->file.refcnt);
2977 write_unlock_bh(&pch->upl);
2979 mutex_unlock(&pn->all_ppp_mutex);
2984 * Disconnect a channel from its ppp unit.
2987 ppp_disconnect_channel(struct channel *pch)
2992 write_lock_bh(&pch->upl);
2995 write_unlock_bh(&pch->upl);
2997 /* remove it from the ppp unit's list */
2999 list_del(&pch->clist);
3000 if (--ppp->n_channels == 0)
3001 wake_up_interruptible(&ppp->file.rwait);
3003 if (atomic_dec_and_test(&ppp->file.refcnt))
3004 ppp_destroy_interface(ppp);
3011 * Free up the resources used by a ppp channel.
3013 static void ppp_destroy_channel(struct channel *pch)
3015 put_net(pch->chan_net);
3016 pch->chan_net = NULL;
3018 atomic_dec(&channel_count);
3020 if (!pch->file.dead) {
3021 /* "can't happen" */
3022 pr_err("ppp: destroying undead channel %p !\n", pch);
3025 skb_queue_purge(&pch->file.xq);
3026 skb_queue_purge(&pch->file.rq);
3030 static void __exit ppp_cleanup(void)
3032 /* should never happen */
3033 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3034 pr_err("PPP: removing module but units remain!\n");
3035 unregister_chrdev(PPP_MAJOR, "ppp");
3036 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3037 class_destroy(ppp_class);
3038 unregister_pernet_device(&ppp_net_ops);
3042 * Units handling. Caller must protect concurrent access
3043 * by holding all_ppp_mutex
3046 /* associate pointer with specified number */
3047 static int unit_set(struct idr *p, void *ptr, int n)
3051 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3052 if (unit == -ENOSPC)
3057 /* get new free unit number and associate pointer with it */
3058 static int unit_get(struct idr *p, void *ptr)
3060 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3063 /* put unit number back to a pool */
3064 static void unit_put(struct idr *p, int n)
3069 /* get pointer associated with the number */
3070 static void *unit_find(struct idr *p, int n)
3072 return idr_find(p, n);
3075 /* Module/initialization stuff */
3077 module_init(ppp_init);
3078 module_exit(ppp_cleanup);
3080 EXPORT_SYMBOL(ppp_register_net_channel);
3081 EXPORT_SYMBOL(ppp_register_channel);
3082 EXPORT_SYMBOL(ppp_unregister_channel);
3083 EXPORT_SYMBOL(ppp_channel_index);
3084 EXPORT_SYMBOL(ppp_unit_number);
3085 EXPORT_SYMBOL(ppp_dev_name);
3086 EXPORT_SYMBOL(ppp_input);
3087 EXPORT_SYMBOL(ppp_input_error);
3088 EXPORT_SYMBOL(ppp_output_wakeup);
3089 EXPORT_SYMBOL(ppp_register_compressor);
3090 EXPORT_SYMBOL(ppp_unregister_compressor);
3091 MODULE_LICENSE("GPL");
3092 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3093 MODULE_ALIAS("devname:ppp");