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)
570 struct ppp_file *pf = file->private_data;
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;
581 return ppp_unattached_ioctl(current->nsproxy->net_ns,
584 if (cmd == PPPIOCDETACH) {
586 * We have to be careful here... if the file descriptor
587 * has been dup'd, we could have another process in the
588 * middle of a poll using the same file *, so we had
589 * better not free the interface data structures -
590 * instead we fail the ioctl. Even in this case, we
591 * shut down the interface if we are the owner of it.
592 * Actually, we should get rid of PPPIOCDETACH, userland
593 * (i.e. pppd) could achieve the same effect by closing
594 * this fd and reopening /dev/ppp.
597 mutex_lock(&ppp_mutex);
598 if (pf->kind == INTERFACE) {
601 if (file == ppp->owner)
602 unregister_netdevice(ppp->dev);
605 if (atomic_long_read(&file->f_count) < 2) {
606 ppp_release(NULL, file);
609 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
610 atomic_long_read(&file->f_count));
611 mutex_unlock(&ppp_mutex);
615 if (pf->kind == CHANNEL) {
617 struct ppp_channel *chan;
619 mutex_lock(&ppp_mutex);
620 pch = PF_TO_CHANNEL(pf);
624 if (get_user(unit, p))
626 err = ppp_connect_channel(pch, unit);
630 err = ppp_disconnect_channel(pch);
634 down_read(&pch->chan_sem);
637 if (chan && chan->ops->ioctl)
638 err = chan->ops->ioctl(chan, cmd, arg);
639 up_read(&pch->chan_sem);
641 mutex_unlock(&ppp_mutex);
645 if (pf->kind != INTERFACE) {
647 pr_err("PPP: not interface or channel??\n");
651 mutex_lock(&ppp_mutex);
655 if (get_user(val, p))
662 if (get_user(val, p))
665 cflags = ppp->flags & ~val;
666 #ifdef CONFIG_PPP_MULTILINK
667 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
670 ppp->flags = val & SC_FLAG_BITS;
672 if (cflags & SC_CCP_OPEN)
678 val = ppp->flags | ppp->xstate | ppp->rstate;
679 if (put_user(val, p))
684 case PPPIOCSCOMPRESS:
685 err = ppp_set_compress(ppp, arg);
689 if (put_user(ppp->file.index, p))
695 if (get_user(val, p))
702 if (put_user(ppp->debug, p))
708 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
709 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
710 if (copy_to_user(argp, &idle, sizeof(idle)))
716 if (get_user(val, p))
719 if ((val >> 16) != 0) {
723 vj = slhc_init(val2+1, val+1);
726 "PPP: no memory (VJ compressor)\n");
740 if (copy_from_user(&npi, argp, sizeof(npi)))
742 err = proto_to_npindex(npi.protocol);
746 if (cmd == PPPIOCGNPMODE) {
748 npi.mode = ppp->npmode[i];
749 if (copy_to_user(argp, &npi, sizeof(npi)))
752 ppp->npmode[i] = npi.mode;
753 /* we may be able to transmit more packets now (??) */
754 netif_wake_queue(ppp->dev);
759 #ifdef CONFIG_PPP_FILTER
762 struct sock_filter *code;
764 err = get_filter(argp, &code);
766 struct bpf_prog *pass_filter = NULL;
767 struct sock_fprog_kern fprog = {
774 err = bpf_prog_create(&pass_filter, &fprog);
777 if (ppp->pass_filter)
778 bpf_prog_destroy(ppp->pass_filter);
779 ppp->pass_filter = pass_filter;
788 struct sock_filter *code;
790 err = get_filter(argp, &code);
792 struct bpf_prog *active_filter = NULL;
793 struct sock_fprog_kern fprog = {
800 err = bpf_prog_create(&active_filter, &fprog);
803 if (ppp->active_filter)
804 bpf_prog_destroy(ppp->active_filter);
805 ppp->active_filter = active_filter;
812 #endif /* CONFIG_PPP_FILTER */
814 #ifdef CONFIG_PPP_MULTILINK
816 if (get_user(val, p))
820 ppp_recv_unlock(ppp);
823 #endif /* CONFIG_PPP_MULTILINK */
828 mutex_unlock(&ppp_mutex);
832 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
833 struct file *file, unsigned int cmd, unsigned long arg)
835 int unit, err = -EFAULT;
837 struct channel *chan;
839 int __user *p = (int __user *)arg;
841 mutex_lock(&ppp_mutex);
844 /* Create a new ppp unit */
845 if (get_user(unit, p))
847 ppp = ppp_create_interface(net, unit, file, &err);
850 file->private_data = &ppp->file;
852 if (put_user(ppp->file.index, p))
858 /* Attach to an existing ppp unit */
859 if (get_user(unit, p))
862 pn = ppp_pernet(net);
863 mutex_lock(&pn->all_ppp_mutex);
864 ppp = ppp_find_unit(pn, unit);
866 atomic_inc(&ppp->file.refcnt);
867 file->private_data = &ppp->file;
870 mutex_unlock(&pn->all_ppp_mutex);
874 if (get_user(unit, p))
877 pn = ppp_pernet(net);
878 spin_lock_bh(&pn->all_channels_lock);
879 chan = ppp_find_channel(pn, unit);
881 atomic_inc(&chan->file.refcnt);
882 file->private_data = &chan->file;
885 spin_unlock_bh(&pn->all_channels_lock);
891 mutex_unlock(&ppp_mutex);
895 static const struct file_operations ppp_device_fops = {
896 .owner = THIS_MODULE,
900 .unlocked_ioctl = ppp_ioctl,
902 .release = ppp_release,
903 .llseek = noop_llseek,
906 static __net_init int ppp_init_net(struct net *net)
908 struct ppp_net *pn = net_generic(net, ppp_net_id);
910 idr_init(&pn->units_idr);
911 mutex_init(&pn->all_ppp_mutex);
913 INIT_LIST_HEAD(&pn->all_channels);
914 INIT_LIST_HEAD(&pn->new_channels);
916 spin_lock_init(&pn->all_channels_lock);
921 static __net_exit void ppp_exit_net(struct net *net)
923 struct ppp_net *pn = net_generic(net, ppp_net_id);
924 struct net_device *dev;
925 struct net_device *aux;
931 for_each_netdev_safe(net, dev, aux) {
932 if (dev->netdev_ops == &ppp_netdev_ops)
933 unregister_netdevice_queue(dev, &list);
936 idr_for_each_entry(&pn->units_idr, ppp, id)
937 /* Skip devices already unregistered by previous loop */
938 if (!net_eq(dev_net(ppp->dev), net))
939 unregister_netdevice_queue(ppp->dev, &list);
941 unregister_netdevice_many(&list);
944 idr_destroy(&pn->units_idr);
947 static struct pernet_operations ppp_net_ops = {
948 .init = ppp_init_net,
949 .exit = ppp_exit_net,
951 .size = sizeof(struct ppp_net),
954 #define PPP_MAJOR 108
956 /* Called at boot time if ppp is compiled into the kernel,
957 or at module load time (from init_module) if compiled as a module. */
958 static int __init ppp_init(void)
962 pr_info("PPP generic driver version " PPP_VERSION "\n");
964 err = register_pernet_device(&ppp_net_ops);
966 pr_err("failed to register PPP pernet device (%d)\n", err);
970 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
972 pr_err("failed to register PPP device (%d)\n", err);
976 ppp_class = class_create(THIS_MODULE, "ppp");
977 if (IS_ERR(ppp_class)) {
978 err = PTR_ERR(ppp_class);
982 /* not a big deal if we fail here :-) */
983 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
988 unregister_chrdev(PPP_MAJOR, "ppp");
990 unregister_pernet_device(&ppp_net_ops);
996 * Network interface unit routines.
999 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1001 struct ppp *ppp = netdev_priv(dev);
1005 npi = ethertype_to_npindex(ntohs(skb->protocol));
1009 /* Drop, accept or reject the packet */
1010 switch (ppp->npmode[npi]) {
1014 /* it would be nice to have a way to tell the network
1015 system to queue this one up for later. */
1022 /* Put the 2-byte PPP protocol number on the front,
1023 making sure there is room for the address and control fields. */
1024 if (skb_cow_head(skb, PPP_HDRLEN))
1027 pp = skb_push(skb, 2);
1028 proto = npindex_to_proto[npi];
1029 put_unaligned_be16(proto, pp);
1031 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1032 skb_queue_tail(&ppp->file.xq, skb);
1033 ppp_xmit_process(ppp);
1034 return NETDEV_TX_OK;
1038 ++dev->stats.tx_dropped;
1039 return NETDEV_TX_OK;
1043 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1045 struct ppp *ppp = netdev_priv(dev);
1047 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1048 struct ppp_stats stats;
1049 struct ppp_comp_stats cstats;
1054 ppp_get_stats(ppp, &stats);
1055 if (copy_to_user(addr, &stats, sizeof(stats)))
1060 case SIOCGPPPCSTATS:
1061 memset(&cstats, 0, sizeof(cstats));
1063 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1065 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1066 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1073 if (copy_to_user(addr, vers, strlen(vers) + 1))
1085 static struct rtnl_link_stats64*
1086 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1088 struct ppp *ppp = netdev_priv(dev);
1091 stats64->rx_packets = ppp->stats64.rx_packets;
1092 stats64->rx_bytes = ppp->stats64.rx_bytes;
1093 ppp_recv_unlock(ppp);
1096 stats64->tx_packets = ppp->stats64.tx_packets;
1097 stats64->tx_bytes = ppp->stats64.tx_bytes;
1098 ppp_xmit_unlock(ppp);
1100 stats64->rx_errors = dev->stats.rx_errors;
1101 stats64->tx_errors = dev->stats.tx_errors;
1102 stats64->rx_dropped = dev->stats.rx_dropped;
1103 stats64->tx_dropped = dev->stats.tx_dropped;
1104 stats64->rx_length_errors = dev->stats.rx_length_errors;
1109 static struct lock_class_key ppp_tx_busylock;
1110 static int ppp_dev_init(struct net_device *dev)
1112 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1116 static void ppp_dev_uninit(struct net_device *dev)
1118 struct ppp *ppp = netdev_priv(dev);
1119 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1125 mutex_lock(&pn->all_ppp_mutex);
1126 unit_put(&pn->units_idr, ppp->file.index);
1127 mutex_unlock(&pn->all_ppp_mutex);
1132 wake_up_interruptible(&ppp->file.rwait);
1135 static const struct net_device_ops ppp_netdev_ops = {
1136 .ndo_init = ppp_dev_init,
1137 .ndo_uninit = ppp_dev_uninit,
1138 .ndo_start_xmit = ppp_start_xmit,
1139 .ndo_do_ioctl = ppp_net_ioctl,
1140 .ndo_get_stats64 = ppp_get_stats64,
1143 static void ppp_setup(struct net_device *dev)
1145 dev->netdev_ops = &ppp_netdev_ops;
1146 dev->hard_header_len = PPP_HDRLEN;
1149 dev->tx_queue_len = 3;
1150 dev->type = ARPHRD_PPP;
1151 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1152 netif_keep_dst(dev);
1156 * Transmit-side routines.
1160 * Called to do any work queued up on the transmit side
1161 * that can now be done.
1164 ppp_xmit_process(struct ppp *ppp)
1166 struct sk_buff *skb;
1169 if (!ppp->closing) {
1171 while (!ppp->xmit_pending &&
1172 (skb = skb_dequeue(&ppp->file.xq)))
1173 ppp_send_frame(ppp, skb);
1174 /* If there's no work left to do, tell the core net
1175 code that we can accept some more. */
1176 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1177 netif_wake_queue(ppp->dev);
1179 netif_stop_queue(ppp->dev);
1181 ppp_xmit_unlock(ppp);
1184 static inline struct sk_buff *
1185 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1187 struct sk_buff *new_skb;
1189 int new_skb_size = ppp->dev->mtu +
1190 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1191 int compressor_skb_size = ppp->dev->mtu +
1192 ppp->xcomp->comp_extra + PPP_HDRLEN;
1193 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1195 if (net_ratelimit())
1196 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1199 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1200 skb_reserve(new_skb,
1201 ppp->dev->hard_header_len - PPP_HDRLEN);
1203 /* compressor still expects A/C bytes in hdr */
1204 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1205 new_skb->data, skb->len + 2,
1206 compressor_skb_size);
1207 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1211 skb_pull(skb, 2); /* pull off A/C bytes */
1212 } else if (len == 0) {
1213 /* didn't compress, or CCP not up yet */
1214 consume_skb(new_skb);
1219 * MPPE requires that we do not send unencrypted
1220 * frames. The compressor will return -1 if we
1221 * should drop the frame. We cannot simply test
1222 * the compress_proto because MPPE and MPPC share
1225 if (net_ratelimit())
1226 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1228 consume_skb(new_skb);
1235 * Compress and send a frame.
1236 * The caller should have locked the xmit path,
1237 * and xmit_pending should be 0.
1240 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1242 int proto = PPP_PROTO(skb);
1243 struct sk_buff *new_skb;
1247 if (proto < 0x8000) {
1248 #ifdef CONFIG_PPP_FILTER
1249 /* check if we should pass this packet */
1250 /* the filter instructions are constructed assuming
1251 a four-byte PPP header on each packet */
1252 *skb_push(skb, 2) = 1;
1253 if (ppp->pass_filter &&
1254 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1256 netdev_printk(KERN_DEBUG, ppp->dev,
1257 "PPP: outbound frame "
1262 /* if this packet passes the active filter, record the time */
1263 if (!(ppp->active_filter &&
1264 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1265 ppp->last_xmit = jiffies;
1268 /* for data packets, record the time */
1269 ppp->last_xmit = jiffies;
1270 #endif /* CONFIG_PPP_FILTER */
1273 ++ppp->stats64.tx_packets;
1274 ppp->stats64.tx_bytes += skb->len - 2;
1278 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1280 /* try to do VJ TCP header compression */
1281 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1284 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1287 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1289 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1290 new_skb->data + 2, &cp,
1291 !(ppp->flags & SC_NO_TCP_CCID));
1292 if (cp == skb->data + 2) {
1293 /* didn't compress */
1294 consume_skb(new_skb);
1296 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1297 proto = PPP_VJC_COMP;
1298 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1300 proto = PPP_VJC_UNCOMP;
1301 cp[0] = skb->data[2];
1305 cp = skb_put(skb, len + 2);
1312 /* peek at outbound CCP frames */
1313 ppp_ccp_peek(ppp, skb, 0);
1317 /* try to do packet compression */
1318 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1319 proto != PPP_LCP && proto != PPP_CCP) {
1320 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1321 if (net_ratelimit())
1322 netdev_err(ppp->dev,
1323 "ppp: compression required but "
1324 "down - pkt dropped.\n");
1327 skb = pad_compress_skb(ppp, skb);
1333 * If we are waiting for traffic (demand dialling),
1334 * queue it up for pppd to receive.
1336 if (ppp->flags & SC_LOOP_TRAFFIC) {
1337 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1339 skb_queue_tail(&ppp->file.rq, skb);
1340 wake_up_interruptible(&ppp->file.rwait);
1344 ppp->xmit_pending = skb;
1350 ++ppp->dev->stats.tx_errors;
1354 * Try to send the frame in xmit_pending.
1355 * The caller should have the xmit path locked.
1358 ppp_push(struct ppp *ppp)
1360 struct list_head *list;
1361 struct channel *pch;
1362 struct sk_buff *skb = ppp->xmit_pending;
1367 list = &ppp->channels;
1368 if (list_empty(list)) {
1369 /* nowhere to send the packet, just drop it */
1370 ppp->xmit_pending = NULL;
1375 if ((ppp->flags & SC_MULTILINK) == 0) {
1376 /* not doing multilink: send it down the first channel */
1378 pch = list_entry(list, struct channel, clist);
1380 spin_lock_bh(&pch->downl);
1382 if (pch->chan->ops->start_xmit(pch->chan, skb))
1383 ppp->xmit_pending = NULL;
1385 /* channel got unregistered */
1387 ppp->xmit_pending = NULL;
1389 spin_unlock_bh(&pch->downl);
1393 #ifdef CONFIG_PPP_MULTILINK
1394 /* Multilink: fragment the packet over as many links
1395 as can take the packet at the moment. */
1396 if (!ppp_mp_explode(ppp, skb))
1398 #endif /* CONFIG_PPP_MULTILINK */
1400 ppp->xmit_pending = NULL;
1404 #ifdef CONFIG_PPP_MULTILINK
1405 static bool mp_protocol_compress __read_mostly = true;
1406 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1407 MODULE_PARM_DESC(mp_protocol_compress,
1408 "compress protocol id in multilink fragments");
1411 * Divide a packet to be transmitted into fragments and
1412 * send them out the individual links.
1414 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1417 int i, bits, hdrlen, mtu;
1419 int navail, nfree, nzero;
1423 unsigned char *p, *q;
1424 struct list_head *list;
1425 struct channel *pch;
1426 struct sk_buff *frag;
1427 struct ppp_channel *chan;
1429 totspeed = 0; /*total bitrate of the bundle*/
1430 nfree = 0; /* # channels which have no packet already queued */
1431 navail = 0; /* total # of usable channels (not deregistered) */
1432 nzero = 0; /* number of channels with zero speed associated*/
1433 totfree = 0; /*total # of channels available and
1434 *having no queued packets before
1435 *starting the fragmentation*/
1437 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1439 list_for_each_entry(pch, &ppp->channels, clist) {
1443 pch->speed = pch->chan->speed;
1448 if (skb_queue_empty(&pch->file.xq) ||
1450 if (pch->speed == 0)
1453 totspeed += pch->speed;
1459 if (!pch->had_frag && i < ppp->nxchan)
1465 * Don't start sending this packet unless at least half of
1466 * the channels are free. This gives much better TCP
1467 * performance if we have a lot of channels.
1469 if (nfree == 0 || nfree < navail / 2)
1470 return 0; /* can't take now, leave it in xmit_pending */
1472 /* Do protocol field compression */
1475 if (*p == 0 && mp_protocol_compress) {
1481 nbigger = len % nfree;
1483 /* skip to the channel after the one we last used
1484 and start at that one */
1485 list = &ppp->channels;
1486 for (i = 0; i < ppp->nxchan; ++i) {
1488 if (list == &ppp->channels) {
1494 /* create a fragment for each channel */
1498 if (list == &ppp->channels) {
1502 pch = list_entry(list, struct channel, clist);
1508 * Skip this channel if it has a fragment pending already and
1509 * we haven't given a fragment to all of the free channels.
1511 if (pch->avail == 1) {
1518 /* check the channel's mtu and whether it is still attached. */
1519 spin_lock_bh(&pch->downl);
1520 if (pch->chan == NULL) {
1521 /* can't use this channel, it's being deregistered */
1522 if (pch->speed == 0)
1525 totspeed -= pch->speed;
1527 spin_unlock_bh(&pch->downl);
1538 *if the channel speed is not set divide
1539 *the packet evenly among the free channels;
1540 *otherwise divide it according to the speed
1541 *of the channel we are going to transmit on
1545 if (pch->speed == 0) {
1552 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1553 ((totspeed*totfree)/pch->speed)) - hdrlen;
1555 flen += ((totfree - nzero)*pch->speed)/totspeed;
1556 nbigger -= ((totfree - nzero)*pch->speed)/
1564 *check if we are on the last channel or
1565 *we exceded the length of the data to
1568 if ((nfree <= 0) || (flen > len))
1571 *it is not worth to tx on slow channels:
1572 *in that case from the resulting flen according to the
1573 *above formula will be equal or less than zero.
1574 *Skip the channel in this case
1578 spin_unlock_bh(&pch->downl);
1583 * hdrlen includes the 2-byte PPP protocol field, but the
1584 * MTU counts only the payload excluding the protocol field.
1585 * (RFC1661 Section 2)
1587 mtu = pch->chan->mtu - (hdrlen - 2);
1594 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1597 q = skb_put(frag, flen + hdrlen);
1599 /* make the MP header */
1600 put_unaligned_be16(PPP_MP, q);
1601 if (ppp->flags & SC_MP_XSHORTSEQ) {
1602 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1606 q[3] = ppp->nxseq >> 16;
1607 q[4] = ppp->nxseq >> 8;
1611 memcpy(q + hdrlen, p, flen);
1613 /* try to send it down the channel */
1615 if (!skb_queue_empty(&pch->file.xq) ||
1616 !chan->ops->start_xmit(chan, frag))
1617 skb_queue_tail(&pch->file.xq, frag);
1623 spin_unlock_bh(&pch->downl);
1630 spin_unlock_bh(&pch->downl);
1632 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1633 ++ppp->dev->stats.tx_errors;
1635 return 1; /* abandon the frame */
1637 #endif /* CONFIG_PPP_MULTILINK */
1640 * Try to send data out on a channel.
1643 ppp_channel_push(struct channel *pch)
1645 struct sk_buff *skb;
1648 spin_lock_bh(&pch->downl);
1650 while (!skb_queue_empty(&pch->file.xq)) {
1651 skb = skb_dequeue(&pch->file.xq);
1652 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1653 /* put the packet back and try again later */
1654 skb_queue_head(&pch->file.xq, skb);
1659 /* channel got deregistered */
1660 skb_queue_purge(&pch->file.xq);
1662 spin_unlock_bh(&pch->downl);
1663 /* see if there is anything from the attached unit to be sent */
1664 if (skb_queue_empty(&pch->file.xq)) {
1665 read_lock_bh(&pch->upl);
1668 ppp_xmit_process(ppp);
1669 read_unlock_bh(&pch->upl);
1674 * Receive-side routines.
1677 struct ppp_mp_skb_parm {
1681 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1684 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1688 ppp_receive_frame(ppp, skb, pch);
1691 ppp_recv_unlock(ppp);
1695 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1697 struct channel *pch = chan->ppp;
1705 read_lock_bh(&pch->upl);
1706 if (!pskb_may_pull(skb, 2)) {
1709 ++pch->ppp->dev->stats.rx_length_errors;
1710 ppp_receive_error(pch->ppp);
1715 proto = PPP_PROTO(skb);
1716 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1717 /* put it on the channel queue */
1718 skb_queue_tail(&pch->file.rq, skb);
1719 /* drop old frames if queue too long */
1720 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1721 (skb = skb_dequeue(&pch->file.rq)))
1723 wake_up_interruptible(&pch->file.rwait);
1725 ppp_do_recv(pch->ppp, skb, pch);
1729 read_unlock_bh(&pch->upl);
1732 /* Put a 0-length skb in the receive queue as an error indication */
1734 ppp_input_error(struct ppp_channel *chan, int code)
1736 struct channel *pch = chan->ppp;
1737 struct sk_buff *skb;
1742 read_lock_bh(&pch->upl);
1744 skb = alloc_skb(0, GFP_ATOMIC);
1746 skb->len = 0; /* probably unnecessary */
1748 ppp_do_recv(pch->ppp, skb, pch);
1751 read_unlock_bh(&pch->upl);
1755 * We come in here to process a received frame.
1756 * The receive side of the ppp unit is locked.
1759 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1761 /* note: a 0-length skb is used as an error indication */
1763 skb_checksum_complete_unset(skb);
1764 #ifdef CONFIG_PPP_MULTILINK
1765 /* XXX do channel-level decompression here */
1766 if (PPP_PROTO(skb) == PPP_MP)
1767 ppp_receive_mp_frame(ppp, skb, pch);
1769 #endif /* CONFIG_PPP_MULTILINK */
1770 ppp_receive_nonmp_frame(ppp, skb);
1773 ppp_receive_error(ppp);
1778 ppp_receive_error(struct ppp *ppp)
1780 ++ppp->dev->stats.rx_errors;
1786 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1789 int proto, len, npi;
1792 * Decompress the frame, if compressed.
1793 * Note that some decompressors need to see uncompressed frames
1794 * that come in as well as compressed frames.
1796 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1797 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1798 skb = ppp_decompress_frame(ppp, skb);
1800 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1803 proto = PPP_PROTO(skb);
1806 /* decompress VJ compressed packets */
1807 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1810 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1811 /* copy to a new sk_buff with more tailroom */
1812 ns = dev_alloc_skb(skb->len + 128);
1814 netdev_err(ppp->dev, "PPP: no memory "
1819 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1824 skb->ip_summed = CHECKSUM_NONE;
1826 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1828 netdev_printk(KERN_DEBUG, ppp->dev,
1829 "PPP: VJ decompression error\n");
1834 skb_put(skb, len - skb->len);
1835 else if (len < skb->len)
1840 case PPP_VJC_UNCOMP:
1841 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1844 /* Until we fix the decompressor need to make sure
1845 * data portion is linear.
1847 if (!pskb_may_pull(skb, skb->len))
1850 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1851 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1858 ppp_ccp_peek(ppp, skb, 1);
1862 ++ppp->stats64.rx_packets;
1863 ppp->stats64.rx_bytes += skb->len - 2;
1865 npi = proto_to_npindex(proto);
1867 /* control or unknown frame - pass it to pppd */
1868 skb_queue_tail(&ppp->file.rq, skb);
1869 /* limit queue length by dropping old frames */
1870 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1871 (skb = skb_dequeue(&ppp->file.rq)))
1873 /* wake up any process polling or blocking on read */
1874 wake_up_interruptible(&ppp->file.rwait);
1877 /* network protocol frame - give it to the kernel */
1879 #ifdef CONFIG_PPP_FILTER
1880 /* check if the packet passes the pass and active filters */
1881 /* the filter instructions are constructed assuming
1882 a four-byte PPP header on each packet */
1883 if (ppp->pass_filter || ppp->active_filter) {
1884 if (skb_unclone(skb, GFP_ATOMIC))
1887 *skb_push(skb, 2) = 0;
1888 if (ppp->pass_filter &&
1889 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1891 netdev_printk(KERN_DEBUG, ppp->dev,
1892 "PPP: inbound frame "
1897 if (!(ppp->active_filter &&
1898 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1899 ppp->last_recv = jiffies;
1902 #endif /* CONFIG_PPP_FILTER */
1903 ppp->last_recv = jiffies;
1905 if ((ppp->dev->flags & IFF_UP) == 0 ||
1906 ppp->npmode[npi] != NPMODE_PASS) {
1909 /* chop off protocol */
1910 skb_pull_rcsum(skb, 2);
1911 skb->dev = ppp->dev;
1912 skb->protocol = htons(npindex_to_ethertype[npi]);
1913 skb_reset_mac_header(skb);
1914 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
1915 dev_net(ppp->dev)));
1923 ppp_receive_error(ppp);
1926 static struct sk_buff *
1927 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1929 int proto = PPP_PROTO(skb);
1933 /* Until we fix all the decompressor's need to make sure
1934 * data portion is linear.
1936 if (!pskb_may_pull(skb, skb->len))
1939 if (proto == PPP_COMP) {
1942 switch(ppp->rcomp->compress_proto) {
1944 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1947 obuff_size = ppp->mru + PPP_HDRLEN;
1951 ns = dev_alloc_skb(obuff_size);
1953 netdev_err(ppp->dev, "ppp_decompress_frame: "
1957 /* the decompressor still expects the A/C bytes in the hdr */
1958 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1959 skb->len + 2, ns->data, obuff_size);
1961 /* Pass the compressed frame to pppd as an
1962 error indication. */
1963 if (len == DECOMP_FATALERROR)
1964 ppp->rstate |= SC_DC_FERROR;
1972 skb_pull(skb, 2); /* pull off the A/C bytes */
1975 /* Uncompressed frame - pass to decompressor so it
1976 can update its dictionary if necessary. */
1977 if (ppp->rcomp->incomp)
1978 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1985 ppp->rstate |= SC_DC_ERROR;
1986 ppp_receive_error(ppp);
1990 #ifdef CONFIG_PPP_MULTILINK
1992 * Receive a multilink frame.
1993 * We put it on the reconstruction queue and then pull off
1994 * as many completed frames as we can.
1997 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2001 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2003 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2004 goto err; /* no good, throw it away */
2006 /* Decode sequence number and begin/end bits */
2007 if (ppp->flags & SC_MP_SHORTSEQ) {
2008 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2011 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2014 PPP_MP_CB(skb)->BEbits = skb->data[2];
2015 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2018 * Do protocol ID decompression on the first fragment of each packet.
2020 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2021 *skb_push(skb, 1) = 0;
2024 * Expand sequence number to 32 bits, making it as close
2025 * as possible to ppp->minseq.
2027 seq |= ppp->minseq & ~mask;
2028 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2030 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2031 seq -= mask + 1; /* should never happen */
2032 PPP_MP_CB(skb)->sequence = seq;
2036 * If this packet comes before the next one we were expecting,
2039 if (seq_before(seq, ppp->nextseq)) {
2041 ++ppp->dev->stats.rx_dropped;
2042 ppp_receive_error(ppp);
2047 * Reevaluate minseq, the minimum over all channels of the
2048 * last sequence number received on each channel. Because of
2049 * the increasing sequence number rule, we know that any fragment
2050 * before `minseq' which hasn't arrived is never going to arrive.
2051 * The list of channels can't change because we have the receive
2052 * side of the ppp unit locked.
2054 list_for_each_entry(ch, &ppp->channels, clist) {
2055 if (seq_before(ch->lastseq, seq))
2058 if (seq_before(ppp->minseq, seq))
2061 /* Put the fragment on the reconstruction queue */
2062 ppp_mp_insert(ppp, skb);
2064 /* If the queue is getting long, don't wait any longer for packets
2065 before the start of the queue. */
2066 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2067 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2068 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2069 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2072 /* Pull completed packets off the queue and receive them. */
2073 while ((skb = ppp_mp_reconstruct(ppp))) {
2074 if (pskb_may_pull(skb, 2))
2075 ppp_receive_nonmp_frame(ppp, skb);
2077 ++ppp->dev->stats.rx_length_errors;
2079 ppp_receive_error(ppp);
2087 ppp_receive_error(ppp);
2091 * Insert a fragment on the MP reconstruction queue.
2092 * The queue is ordered by increasing sequence number.
2095 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2098 struct sk_buff_head *list = &ppp->mrq;
2099 u32 seq = PPP_MP_CB(skb)->sequence;
2101 /* N.B. we don't need to lock the list lock because we have the
2102 ppp unit receive-side lock. */
2103 skb_queue_walk(list, p) {
2104 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2107 __skb_queue_before(list, p, skb);
2111 * Reconstruct a packet from the MP fragment queue.
2112 * We go through increasing sequence numbers until we find a
2113 * complete packet, or we get to the sequence number for a fragment
2114 * which hasn't arrived but might still do so.
2116 static struct sk_buff *
2117 ppp_mp_reconstruct(struct ppp *ppp)
2119 u32 seq = ppp->nextseq;
2120 u32 minseq = ppp->minseq;
2121 struct sk_buff_head *list = &ppp->mrq;
2122 struct sk_buff *p, *tmp;
2123 struct sk_buff *head, *tail;
2124 struct sk_buff *skb = NULL;
2125 int lost = 0, len = 0;
2127 if (ppp->mrru == 0) /* do nothing until mrru is set */
2131 skb_queue_walk_safe(list, p, tmp) {
2133 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2134 /* this can't happen, anyway ignore the skb */
2135 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2137 PPP_MP_CB(p)->sequence, seq);
2138 __skb_unlink(p, list);
2142 if (PPP_MP_CB(p)->sequence != seq) {
2144 /* Fragment `seq' is missing. If it is after
2145 minseq, it might arrive later, so stop here. */
2146 if (seq_after(seq, minseq))
2148 /* Fragment `seq' is lost, keep going. */
2151 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2152 minseq + 1: PPP_MP_CB(p)->sequence;
2155 netdev_printk(KERN_DEBUG, ppp->dev,
2156 "lost frag %u..%u\n",
2163 * At this point we know that all the fragments from
2164 * ppp->nextseq to seq are either present or lost.
2165 * Also, there are no complete packets in the queue
2166 * that have no missing fragments and end before this
2170 /* B bit set indicates this fragment starts a packet */
2171 if (PPP_MP_CB(p)->BEbits & B) {
2179 /* Got a complete packet yet? */
2180 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2181 (PPP_MP_CB(head)->BEbits & B)) {
2182 if (len > ppp->mrru + 2) {
2183 ++ppp->dev->stats.rx_length_errors;
2184 netdev_printk(KERN_DEBUG, ppp->dev,
2185 "PPP: reconstructed packet"
2186 " is too long (%d)\n", len);
2191 ppp->nextseq = seq + 1;
2195 * If this is the ending fragment of a packet,
2196 * and we haven't found a complete valid packet yet,
2197 * we can discard up to and including this fragment.
2199 if (PPP_MP_CB(p)->BEbits & E) {
2200 struct sk_buff *tmp2;
2202 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2204 netdev_printk(KERN_DEBUG, ppp->dev,
2205 "discarding frag %u\n",
2206 PPP_MP_CB(p)->sequence);
2207 __skb_unlink(p, list);
2210 head = skb_peek(list);
2217 /* If we have a complete packet, copy it all into one skb. */
2219 /* If we have discarded any fragments,
2220 signal a receive error. */
2221 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2222 skb_queue_walk_safe(list, p, tmp) {
2226 netdev_printk(KERN_DEBUG, ppp->dev,
2227 "discarding frag %u\n",
2228 PPP_MP_CB(p)->sequence);
2229 __skb_unlink(p, list);
2234 netdev_printk(KERN_DEBUG, ppp->dev,
2235 " missed pkts %u..%u\n",
2237 PPP_MP_CB(head)->sequence-1);
2238 ++ppp->dev->stats.rx_dropped;
2239 ppp_receive_error(ppp);
2244 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2245 p = skb_queue_next(list, head);
2246 __skb_unlink(skb, list);
2247 skb_queue_walk_from_safe(list, p, tmp) {
2248 __skb_unlink(p, list);
2254 skb->data_len += p->len;
2255 skb->truesize += p->truesize;
2261 __skb_unlink(skb, list);
2264 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2269 #endif /* CONFIG_PPP_MULTILINK */
2272 * Channel interface.
2275 /* Create a new, unattached ppp channel. */
2276 int ppp_register_channel(struct ppp_channel *chan)
2278 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2281 /* Create a new, unattached ppp channel for specified net. */
2282 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2284 struct channel *pch;
2287 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2291 pn = ppp_pernet(net);
2295 pch->chan_net = net;
2297 init_ppp_file(&pch->file, CHANNEL);
2298 pch->file.hdrlen = chan->hdrlen;
2299 #ifdef CONFIG_PPP_MULTILINK
2301 #endif /* CONFIG_PPP_MULTILINK */
2302 init_rwsem(&pch->chan_sem);
2303 spin_lock_init(&pch->downl);
2304 rwlock_init(&pch->upl);
2306 spin_lock_bh(&pn->all_channels_lock);
2307 pch->file.index = ++pn->last_channel_index;
2308 list_add(&pch->list, &pn->new_channels);
2309 atomic_inc(&channel_count);
2310 spin_unlock_bh(&pn->all_channels_lock);
2316 * Return the index of a channel.
2318 int ppp_channel_index(struct ppp_channel *chan)
2320 struct channel *pch = chan->ppp;
2323 return pch->file.index;
2328 * Return the PPP unit number to which a channel is connected.
2330 int ppp_unit_number(struct ppp_channel *chan)
2332 struct channel *pch = chan->ppp;
2336 read_lock_bh(&pch->upl);
2338 unit = pch->ppp->file.index;
2339 read_unlock_bh(&pch->upl);
2345 * Return the PPP device interface name of a channel.
2347 char *ppp_dev_name(struct ppp_channel *chan)
2349 struct channel *pch = chan->ppp;
2353 read_lock_bh(&pch->upl);
2354 if (pch->ppp && pch->ppp->dev)
2355 name = pch->ppp->dev->name;
2356 read_unlock_bh(&pch->upl);
2363 * Disconnect a channel from the generic layer.
2364 * This must be called in process context.
2367 ppp_unregister_channel(struct ppp_channel *chan)
2369 struct channel *pch = chan->ppp;
2373 return; /* should never happen */
2378 * This ensures that we have returned from any calls into the
2379 * the channel's start_xmit or ioctl routine before we proceed.
2381 down_write(&pch->chan_sem);
2382 spin_lock_bh(&pch->downl);
2384 spin_unlock_bh(&pch->downl);
2385 up_write(&pch->chan_sem);
2386 ppp_disconnect_channel(pch);
2388 pn = ppp_pernet(pch->chan_net);
2389 spin_lock_bh(&pn->all_channels_lock);
2390 list_del(&pch->list);
2391 spin_unlock_bh(&pn->all_channels_lock);
2394 wake_up_interruptible(&pch->file.rwait);
2395 if (atomic_dec_and_test(&pch->file.refcnt))
2396 ppp_destroy_channel(pch);
2400 * Callback from a channel when it can accept more to transmit.
2401 * This should be called at BH/softirq level, not interrupt level.
2404 ppp_output_wakeup(struct ppp_channel *chan)
2406 struct channel *pch = chan->ppp;
2410 ppp_channel_push(pch);
2414 * Compression control.
2417 /* Process the PPPIOCSCOMPRESS ioctl. */
2419 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2422 struct compressor *cp, *ocomp;
2423 struct ppp_option_data data;
2424 void *state, *ostate;
2425 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2428 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2429 (data.length <= CCP_MAX_OPTION_LENGTH &&
2430 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2433 if (data.length > CCP_MAX_OPTION_LENGTH ||
2434 ccp_option[1] < 2 || ccp_option[1] > data.length)
2437 cp = try_then_request_module(
2438 find_compressor(ccp_option[0]),
2439 "ppp-compress-%d", ccp_option[0]);
2444 if (data.transmit) {
2445 state = cp->comp_alloc(ccp_option, data.length);
2448 ppp->xstate &= ~SC_COMP_RUN;
2450 ostate = ppp->xc_state;
2452 ppp->xc_state = state;
2453 ppp_xmit_unlock(ppp);
2455 ocomp->comp_free(ostate);
2456 module_put(ocomp->owner);
2460 module_put(cp->owner);
2463 state = cp->decomp_alloc(ccp_option, data.length);
2466 ppp->rstate &= ~SC_DECOMP_RUN;
2468 ostate = ppp->rc_state;
2470 ppp->rc_state = state;
2471 ppp_recv_unlock(ppp);
2473 ocomp->decomp_free(ostate);
2474 module_put(ocomp->owner);
2478 module_put(cp->owner);
2486 * Look at a CCP packet and update our state accordingly.
2487 * We assume the caller has the xmit or recv path locked.
2490 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2495 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2496 return; /* no header */
2499 switch (CCP_CODE(dp)) {
2502 /* A ConfReq starts negotiation of compression
2503 * in one direction of transmission,
2504 * and hence brings it down...but which way?
2507 * A ConfReq indicates what the sender would like to receive
2510 /* He is proposing what I should send */
2511 ppp->xstate &= ~SC_COMP_RUN;
2513 /* I am proposing to what he should send */
2514 ppp->rstate &= ~SC_DECOMP_RUN;
2521 * CCP is going down, both directions of transmission
2523 ppp->rstate &= ~SC_DECOMP_RUN;
2524 ppp->xstate &= ~SC_COMP_RUN;
2528 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2530 len = CCP_LENGTH(dp);
2531 if (!pskb_may_pull(skb, len + 2))
2532 return; /* too short */
2535 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2538 /* we will start receiving compressed packets */
2541 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2542 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2543 ppp->rstate |= SC_DECOMP_RUN;
2544 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2547 /* we will soon start sending compressed packets */
2550 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2551 ppp->file.index, 0, ppp->debug))
2552 ppp->xstate |= SC_COMP_RUN;
2557 /* reset the [de]compressor */
2558 if ((ppp->flags & SC_CCP_UP) == 0)
2561 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2562 ppp->rcomp->decomp_reset(ppp->rc_state);
2563 ppp->rstate &= ~SC_DC_ERROR;
2566 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2567 ppp->xcomp->comp_reset(ppp->xc_state);
2573 /* Free up compression resources. */
2575 ppp_ccp_closed(struct ppp *ppp)
2577 void *xstate, *rstate;
2578 struct compressor *xcomp, *rcomp;
2581 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2584 xstate = ppp->xc_state;
2585 ppp->xc_state = NULL;
2588 rstate = ppp->rc_state;
2589 ppp->rc_state = NULL;
2593 xcomp->comp_free(xstate);
2594 module_put(xcomp->owner);
2597 rcomp->decomp_free(rstate);
2598 module_put(rcomp->owner);
2602 /* List of compressors. */
2603 static LIST_HEAD(compressor_list);
2604 static DEFINE_SPINLOCK(compressor_list_lock);
2606 struct compressor_entry {
2607 struct list_head list;
2608 struct compressor *comp;
2611 static struct compressor_entry *
2612 find_comp_entry(int proto)
2614 struct compressor_entry *ce;
2616 list_for_each_entry(ce, &compressor_list, list) {
2617 if (ce->comp->compress_proto == proto)
2623 /* Register a compressor */
2625 ppp_register_compressor(struct compressor *cp)
2627 struct compressor_entry *ce;
2629 spin_lock(&compressor_list_lock);
2631 if (find_comp_entry(cp->compress_proto))
2634 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2639 list_add(&ce->list, &compressor_list);
2641 spin_unlock(&compressor_list_lock);
2645 /* Unregister a compressor */
2647 ppp_unregister_compressor(struct compressor *cp)
2649 struct compressor_entry *ce;
2651 spin_lock(&compressor_list_lock);
2652 ce = find_comp_entry(cp->compress_proto);
2653 if (ce && ce->comp == cp) {
2654 list_del(&ce->list);
2657 spin_unlock(&compressor_list_lock);
2660 /* Find a compressor. */
2661 static struct compressor *
2662 find_compressor(int type)
2664 struct compressor_entry *ce;
2665 struct compressor *cp = NULL;
2667 spin_lock(&compressor_list_lock);
2668 ce = find_comp_entry(type);
2671 if (!try_module_get(cp->owner))
2674 spin_unlock(&compressor_list_lock);
2679 * Miscelleneous stuff.
2683 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2685 struct slcompress *vj = ppp->vj;
2687 memset(st, 0, sizeof(*st));
2688 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2689 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2690 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2691 st->p.ppp_opackets = ppp->stats64.tx_packets;
2692 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2693 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2696 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2697 st->vj.vjs_compressed = vj->sls_o_compressed;
2698 st->vj.vjs_searches = vj->sls_o_searches;
2699 st->vj.vjs_misses = vj->sls_o_misses;
2700 st->vj.vjs_errorin = vj->sls_i_error;
2701 st->vj.vjs_tossed = vj->sls_i_tossed;
2702 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2703 st->vj.vjs_compressedin = vj->sls_i_compressed;
2707 * Stuff for handling the lists of ppp units and channels
2708 * and for initialization.
2712 * Create a new ppp interface unit. Fails if it can't allocate memory
2713 * or if there is already a unit with the requested number.
2714 * unit == -1 means allocate a new number.
2716 static struct ppp *ppp_create_interface(struct net *net, int unit,
2717 struct file *file, int *retp)
2721 struct net_device *dev = NULL;
2725 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN,
2730 pn = ppp_pernet(net);
2732 ppp = netdev_priv(dev);
2735 init_ppp_file(&ppp->file, INTERFACE);
2736 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2738 for (i = 0; i < NUM_NP; ++i)
2739 ppp->npmode[i] = NPMODE_PASS;
2740 INIT_LIST_HEAD(&ppp->channels);
2741 spin_lock_init(&ppp->rlock);
2742 spin_lock_init(&ppp->wlock);
2743 #ifdef CONFIG_PPP_MULTILINK
2745 skb_queue_head_init(&ppp->mrq);
2746 #endif /* CONFIG_PPP_MULTILINK */
2747 #ifdef CONFIG_PPP_FILTER
2748 ppp->pass_filter = NULL;
2749 ppp->active_filter = NULL;
2750 #endif /* CONFIG_PPP_FILTER */
2753 * drum roll: don't forget to set
2754 * the net device is belong to
2756 dev_net_set(dev, net);
2758 mutex_lock(&pn->all_ppp_mutex);
2761 unit = unit_get(&pn->units_idr, ppp);
2768 if (unit_find(&pn->units_idr, unit))
2769 goto out2; /* unit already exists */
2771 * if caller need a specified unit number
2772 * lets try to satisfy him, otherwise --
2773 * he should better ask us for new unit number
2775 * NOTE: yes I know that returning EEXIST it's not
2776 * fair but at least pppd will ask us to allocate
2777 * new unit in this case so user is happy :)
2779 unit = unit_set(&pn->units_idr, ppp, unit);
2784 /* Initialize the new ppp unit */
2785 ppp->file.index = unit;
2786 sprintf(dev->name, "ppp%d", unit);
2788 ret = register_netdev(dev);
2790 unit_put(&pn->units_idr, unit);
2791 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2798 atomic_inc(&ppp_unit_count);
2799 mutex_unlock(&pn->all_ppp_mutex);
2805 mutex_unlock(&pn->all_ppp_mutex);
2813 * Initialize a ppp_file structure.
2816 init_ppp_file(struct ppp_file *pf, int kind)
2819 skb_queue_head_init(&pf->xq);
2820 skb_queue_head_init(&pf->rq);
2821 atomic_set(&pf->refcnt, 1);
2822 init_waitqueue_head(&pf->rwait);
2826 * Free the memory used by a ppp unit. This is only called once
2827 * there are no channels connected to the unit and no file structs
2828 * that reference the unit.
2830 static void ppp_destroy_interface(struct ppp *ppp)
2832 atomic_dec(&ppp_unit_count);
2834 if (!ppp->file.dead || ppp->n_channels) {
2835 /* "can't happen" */
2836 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2837 "but dead=%d n_channels=%d !\n",
2838 ppp, ppp->file.dead, ppp->n_channels);
2842 ppp_ccp_closed(ppp);
2847 skb_queue_purge(&ppp->file.xq);
2848 skb_queue_purge(&ppp->file.rq);
2849 #ifdef CONFIG_PPP_MULTILINK
2850 skb_queue_purge(&ppp->mrq);
2851 #endif /* CONFIG_PPP_MULTILINK */
2852 #ifdef CONFIG_PPP_FILTER
2853 if (ppp->pass_filter) {
2854 bpf_prog_destroy(ppp->pass_filter);
2855 ppp->pass_filter = NULL;
2858 if (ppp->active_filter) {
2859 bpf_prog_destroy(ppp->active_filter);
2860 ppp->active_filter = NULL;
2862 #endif /* CONFIG_PPP_FILTER */
2864 kfree_skb(ppp->xmit_pending);
2866 free_netdev(ppp->dev);
2870 * Locate an existing ppp unit.
2871 * The caller should have locked the all_ppp_mutex.
2874 ppp_find_unit(struct ppp_net *pn, int unit)
2876 return unit_find(&pn->units_idr, unit);
2880 * Locate an existing ppp channel.
2881 * The caller should have locked the all_channels_lock.
2882 * First we look in the new_channels list, then in the
2883 * all_channels list. If found in the new_channels list,
2884 * we move it to the all_channels list. This is for speed
2885 * when we have a lot of channels in use.
2887 static struct channel *
2888 ppp_find_channel(struct ppp_net *pn, int unit)
2890 struct channel *pch;
2892 list_for_each_entry(pch, &pn->new_channels, list) {
2893 if (pch->file.index == unit) {
2894 list_move(&pch->list, &pn->all_channels);
2899 list_for_each_entry(pch, &pn->all_channels, list) {
2900 if (pch->file.index == unit)
2908 * Connect a PPP channel to a PPP interface unit.
2911 ppp_connect_channel(struct channel *pch, int unit)
2918 pn = ppp_pernet(pch->chan_net);
2920 mutex_lock(&pn->all_ppp_mutex);
2921 ppp = ppp_find_unit(pn, unit);
2924 write_lock_bh(&pch->upl);
2930 if (pch->file.hdrlen > ppp->file.hdrlen)
2931 ppp->file.hdrlen = pch->file.hdrlen;
2932 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2933 if (hdrlen > ppp->dev->hard_header_len)
2934 ppp->dev->hard_header_len = hdrlen;
2935 list_add_tail(&pch->clist, &ppp->channels);
2938 atomic_inc(&ppp->file.refcnt);
2943 write_unlock_bh(&pch->upl);
2945 mutex_unlock(&pn->all_ppp_mutex);
2950 * Disconnect a channel from its ppp unit.
2953 ppp_disconnect_channel(struct channel *pch)
2958 write_lock_bh(&pch->upl);
2961 write_unlock_bh(&pch->upl);
2963 /* remove it from the ppp unit's list */
2965 list_del(&pch->clist);
2966 if (--ppp->n_channels == 0)
2967 wake_up_interruptible(&ppp->file.rwait);
2969 if (atomic_dec_and_test(&ppp->file.refcnt))
2970 ppp_destroy_interface(ppp);
2977 * Free up the resources used by a ppp channel.
2979 static void ppp_destroy_channel(struct channel *pch)
2981 atomic_dec(&channel_count);
2983 if (!pch->file.dead) {
2984 /* "can't happen" */
2985 pr_err("ppp: destroying undead channel %p !\n", pch);
2988 skb_queue_purge(&pch->file.xq);
2989 skb_queue_purge(&pch->file.rq);
2993 static void __exit ppp_cleanup(void)
2995 /* should never happen */
2996 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2997 pr_err("PPP: removing module but units remain!\n");
2998 unregister_chrdev(PPP_MAJOR, "ppp");
2999 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3000 class_destroy(ppp_class);
3001 unregister_pernet_device(&ppp_net_ops);
3005 * Units handling. Caller must protect concurrent access
3006 * by holding all_ppp_mutex
3009 /* associate pointer with specified number */
3010 static int unit_set(struct idr *p, void *ptr, int n)
3014 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3015 if (unit == -ENOSPC)
3020 /* get new free unit number and associate pointer with it */
3021 static int unit_get(struct idr *p, void *ptr)
3023 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3026 /* put unit number back to a pool */
3027 static void unit_put(struct idr *p, int n)
3032 /* get pointer associated with the number */
3033 static void *unit_find(struct idr *p, int n)
3035 return idr_find(p, n);
3038 /* Module/initialization stuff */
3040 module_init(ppp_init);
3041 module_exit(ppp_cleanup);
3043 EXPORT_SYMBOL(ppp_register_net_channel);
3044 EXPORT_SYMBOL(ppp_register_channel);
3045 EXPORT_SYMBOL(ppp_unregister_channel);
3046 EXPORT_SYMBOL(ppp_channel_index);
3047 EXPORT_SYMBOL(ppp_unit_number);
3048 EXPORT_SYMBOL(ppp_dev_name);
3049 EXPORT_SYMBOL(ppp_input);
3050 EXPORT_SYMBOL(ppp_input_error);
3051 EXPORT_SYMBOL(ppp_output_wakeup);
3052 EXPORT_SYMBOL(ppp_register_compressor);
3053 EXPORT_SYMBOL(ppp_unregister_compressor);
3054 MODULE_LICENSE("GPL");
3055 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3056 MODULE_ALIAS("devname:ppp");