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, int *retp);
273 static void init_ppp_file(struct ppp_file *pf, int kind);
274 static void ppp_shutdown_interface(struct ppp *ppp);
275 static void ppp_destroy_interface(struct ppp *ppp);
276 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
277 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
278 static int ppp_connect_channel(struct channel *pch, int unit);
279 static int ppp_disconnect_channel(struct channel *pch);
280 static void ppp_destroy_channel(struct channel *pch);
281 static int unit_get(struct idr *p, void *ptr);
282 static int unit_set(struct idr *p, void *ptr, int n);
283 static void unit_put(struct idr *p, int n);
284 static void *unit_find(struct idr *p, int n);
286 static struct class *ppp_class;
288 /* per net-namespace data */
289 static inline struct ppp_net *ppp_pernet(struct net *net)
293 return net_generic(net, ppp_net_id);
296 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
297 static inline int proto_to_npindex(int proto)
316 /* Translates an NP index into a PPP protocol number */
317 static const int npindex_to_proto[NUM_NP] = {
326 /* Translates an ethertype into an NP index */
327 static inline int ethertype_to_npindex(int ethertype)
347 /* Translates an NP index into an ethertype */
348 static const int npindex_to_ethertype[NUM_NP] = {
360 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
361 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
362 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
363 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
364 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
365 ppp_recv_lock(ppp); } while (0)
366 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
367 ppp_xmit_unlock(ppp); } while (0)
370 * /dev/ppp device routines.
371 * The /dev/ppp device is used by pppd to control the ppp unit.
372 * It supports the read, write, ioctl and poll functions.
373 * Open instances of /dev/ppp can be in one of three states:
374 * unattached, attached to a ppp unit, or attached to a ppp channel.
376 static int ppp_open(struct inode *inode, struct file *file)
379 * This could (should?) be enforced by the permissions on /dev/ppp.
381 if (!capable(CAP_NET_ADMIN))
386 static int ppp_release(struct inode *unused, struct file *file)
388 struct ppp_file *pf = file->private_data;
392 file->private_data = NULL;
393 if (pf->kind == INTERFACE) {
395 if (file == ppp->owner)
396 ppp_shutdown_interface(ppp);
398 if (atomic_dec_and_test(&pf->refcnt)) {
401 ppp_destroy_interface(PF_TO_PPP(pf));
404 ppp_destroy_channel(PF_TO_CHANNEL(pf));
412 static ssize_t ppp_read(struct file *file, char __user *buf,
413 size_t count, loff_t *ppos)
415 struct ppp_file *pf = file->private_data;
416 DECLARE_WAITQUEUE(wait, current);
418 struct sk_buff *skb = NULL;
426 add_wait_queue(&pf->rwait, &wait);
428 set_current_state(TASK_INTERRUPTIBLE);
429 skb = skb_dequeue(&pf->rq);
435 if (pf->kind == INTERFACE) {
437 * Return 0 (EOF) on an interface that has no
438 * channels connected, unless it is looping
439 * network traffic (demand mode).
441 struct ppp *ppp = PF_TO_PPP(pf);
442 if (ppp->n_channels == 0 &&
443 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
447 if (file->f_flags & O_NONBLOCK)
450 if (signal_pending(current))
454 set_current_state(TASK_RUNNING);
455 remove_wait_queue(&pf->rwait, &wait);
461 if (skb->len > count)
466 iov_iter_init(&to, READ, &iov, 1, count);
467 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
477 static ssize_t ppp_write(struct file *file, const char __user *buf,
478 size_t count, loff_t *ppos)
480 struct ppp_file *pf = file->private_data;
487 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
490 skb_reserve(skb, pf->hdrlen);
492 if (copy_from_user(skb_put(skb, count), buf, count)) {
497 skb_queue_tail(&pf->xq, skb);
501 ppp_xmit_process(PF_TO_PPP(pf));
504 ppp_channel_push(PF_TO_CHANNEL(pf));
514 /* No kernel lock - fine */
515 static unsigned int ppp_poll(struct file *file, poll_table *wait)
517 struct ppp_file *pf = file->private_data;
522 poll_wait(file, &pf->rwait, wait);
523 mask = POLLOUT | POLLWRNORM;
524 if (skb_peek(&pf->rq))
525 mask |= POLLIN | POLLRDNORM;
528 else if (pf->kind == INTERFACE) {
529 /* see comment in ppp_read */
530 struct ppp *ppp = PF_TO_PPP(pf);
531 if (ppp->n_channels == 0 &&
532 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
533 mask |= POLLIN | POLLRDNORM;
539 #ifdef CONFIG_PPP_FILTER
540 static int get_filter(void __user *arg, struct sock_filter **p)
542 struct sock_fprog uprog;
543 struct sock_filter *code = NULL;
546 if (copy_from_user(&uprog, arg, sizeof(uprog)))
554 len = uprog.len * sizeof(struct sock_filter);
555 code = memdup_user(uprog.filter, len);
557 return PTR_ERR(code);
562 #endif /* CONFIG_PPP_FILTER */
564 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
566 struct ppp_file *pf = file->private_data;
568 int err = -EFAULT, val, val2, i;
569 struct ppp_idle idle;
572 struct slcompress *vj;
573 void __user *argp = (void __user *)arg;
574 int __user *p = argp;
577 return ppp_unattached_ioctl(current->nsproxy->net_ns,
580 if (cmd == PPPIOCDETACH) {
582 * We have to be careful here... if the file descriptor
583 * has been dup'd, we could have another process in the
584 * middle of a poll using the same file *, so we had
585 * better not free the interface data structures -
586 * instead we fail the ioctl. Even in this case, we
587 * shut down the interface if we are the owner of it.
588 * Actually, we should get rid of PPPIOCDETACH, userland
589 * (i.e. pppd) could achieve the same effect by closing
590 * this fd and reopening /dev/ppp.
593 mutex_lock(&ppp_mutex);
594 if (pf->kind == INTERFACE) {
596 if (file == ppp->owner)
597 ppp_shutdown_interface(ppp);
599 if (atomic_long_read(&file->f_count) < 2) {
600 ppp_release(NULL, file);
603 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
604 atomic_long_read(&file->f_count));
605 mutex_unlock(&ppp_mutex);
609 if (pf->kind == CHANNEL) {
611 struct ppp_channel *chan;
613 mutex_lock(&ppp_mutex);
614 pch = PF_TO_CHANNEL(pf);
618 if (get_user(unit, p))
620 err = ppp_connect_channel(pch, unit);
624 err = ppp_disconnect_channel(pch);
628 down_read(&pch->chan_sem);
631 if (chan && chan->ops->ioctl)
632 err = chan->ops->ioctl(chan, cmd, arg);
633 up_read(&pch->chan_sem);
635 mutex_unlock(&ppp_mutex);
639 if (pf->kind != INTERFACE) {
641 pr_err("PPP: not interface or channel??\n");
645 mutex_lock(&ppp_mutex);
649 if (get_user(val, p))
656 if (get_user(val, p))
659 cflags = ppp->flags & ~val;
660 #ifdef CONFIG_PPP_MULTILINK
661 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
664 ppp->flags = val & SC_FLAG_BITS;
666 if (cflags & SC_CCP_OPEN)
672 val = ppp->flags | ppp->xstate | ppp->rstate;
673 if (put_user(val, p))
678 case PPPIOCSCOMPRESS:
679 err = ppp_set_compress(ppp, arg);
683 if (put_user(ppp->file.index, p))
689 if (get_user(val, p))
696 if (put_user(ppp->debug, p))
702 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
703 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
704 if (copy_to_user(argp, &idle, sizeof(idle)))
710 if (get_user(val, p))
713 if ((val >> 16) != 0) {
717 vj = slhc_init(val2+1, val+1);
720 "PPP: no memory (VJ compressor)\n");
734 if (copy_from_user(&npi, argp, sizeof(npi)))
736 err = proto_to_npindex(npi.protocol);
740 if (cmd == PPPIOCGNPMODE) {
742 npi.mode = ppp->npmode[i];
743 if (copy_to_user(argp, &npi, sizeof(npi)))
746 ppp->npmode[i] = npi.mode;
747 /* we may be able to transmit more packets now (??) */
748 netif_wake_queue(ppp->dev);
753 #ifdef CONFIG_PPP_FILTER
756 struct sock_filter *code;
758 err = get_filter(argp, &code);
760 struct bpf_prog *pass_filter = NULL;
761 struct sock_fprog_kern fprog = {
768 err = bpf_prog_create(&pass_filter, &fprog);
771 if (ppp->pass_filter)
772 bpf_prog_destroy(ppp->pass_filter);
773 ppp->pass_filter = pass_filter;
782 struct sock_filter *code;
784 err = get_filter(argp, &code);
786 struct bpf_prog *active_filter = NULL;
787 struct sock_fprog_kern fprog = {
794 err = bpf_prog_create(&active_filter, &fprog);
797 if (ppp->active_filter)
798 bpf_prog_destroy(ppp->active_filter);
799 ppp->active_filter = active_filter;
806 #endif /* CONFIG_PPP_FILTER */
808 #ifdef CONFIG_PPP_MULTILINK
810 if (get_user(val, p))
814 ppp_recv_unlock(ppp);
817 #endif /* CONFIG_PPP_MULTILINK */
822 mutex_unlock(&ppp_mutex);
826 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
827 struct file *file, unsigned int cmd, unsigned long arg)
829 int unit, err = -EFAULT;
831 struct channel *chan;
833 int __user *p = (int __user *)arg;
835 mutex_lock(&ppp_mutex);
838 /* Create a new ppp unit */
839 if (get_user(unit, p))
841 ppp = ppp_create_interface(net, unit, &err);
844 file->private_data = &ppp->file;
847 if (put_user(ppp->file.index, p))
853 /* Attach to an existing ppp unit */
854 if (get_user(unit, p))
857 pn = ppp_pernet(net);
858 mutex_lock(&pn->all_ppp_mutex);
859 ppp = ppp_find_unit(pn, unit);
861 atomic_inc(&ppp->file.refcnt);
862 file->private_data = &ppp->file;
865 mutex_unlock(&pn->all_ppp_mutex);
869 if (get_user(unit, p))
872 pn = ppp_pernet(net);
873 spin_lock_bh(&pn->all_channels_lock);
874 chan = ppp_find_channel(pn, unit);
876 atomic_inc(&chan->file.refcnt);
877 file->private_data = &chan->file;
880 spin_unlock_bh(&pn->all_channels_lock);
886 mutex_unlock(&ppp_mutex);
890 static const struct file_operations ppp_device_fops = {
891 .owner = THIS_MODULE,
895 .unlocked_ioctl = ppp_ioctl,
897 .release = ppp_release,
898 .llseek = noop_llseek,
901 static __net_init int ppp_init_net(struct net *net)
903 struct ppp_net *pn = net_generic(net, ppp_net_id);
905 idr_init(&pn->units_idr);
906 mutex_init(&pn->all_ppp_mutex);
908 INIT_LIST_HEAD(&pn->all_channels);
909 INIT_LIST_HEAD(&pn->new_channels);
911 spin_lock_init(&pn->all_channels_lock);
916 static __net_exit void ppp_exit_net(struct net *net)
918 struct ppp_net *pn = net_generic(net, ppp_net_id);
920 idr_destroy(&pn->units_idr);
923 static struct pernet_operations ppp_net_ops = {
924 .init = ppp_init_net,
925 .exit = ppp_exit_net,
927 .size = sizeof(struct ppp_net),
930 #define PPP_MAJOR 108
932 /* Called at boot time if ppp is compiled into the kernel,
933 or at module load time (from init_module) if compiled as a module. */
934 static int __init ppp_init(void)
938 pr_info("PPP generic driver version " PPP_VERSION "\n");
940 err = register_pernet_device(&ppp_net_ops);
942 pr_err("failed to register PPP pernet device (%d)\n", err);
946 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
948 pr_err("failed to register PPP device (%d)\n", err);
952 ppp_class = class_create(THIS_MODULE, "ppp");
953 if (IS_ERR(ppp_class)) {
954 err = PTR_ERR(ppp_class);
958 /* not a big deal if we fail here :-) */
959 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
964 unregister_chrdev(PPP_MAJOR, "ppp");
966 unregister_pernet_device(&ppp_net_ops);
972 * Network interface unit routines.
975 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
977 struct ppp *ppp = netdev_priv(dev);
981 npi = ethertype_to_npindex(ntohs(skb->protocol));
985 /* Drop, accept or reject the packet */
986 switch (ppp->npmode[npi]) {
990 /* it would be nice to have a way to tell the network
991 system to queue this one up for later. */
998 /* Put the 2-byte PPP protocol number on the front,
999 making sure there is room for the address and control fields. */
1000 if (skb_cow_head(skb, PPP_HDRLEN))
1003 pp = skb_push(skb, 2);
1004 proto = npindex_to_proto[npi];
1005 put_unaligned_be16(proto, pp);
1007 skb_queue_tail(&ppp->file.xq, skb);
1008 ppp_xmit_process(ppp);
1009 return NETDEV_TX_OK;
1013 ++dev->stats.tx_dropped;
1014 return NETDEV_TX_OK;
1018 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1020 struct ppp *ppp = netdev_priv(dev);
1022 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1023 struct ppp_stats stats;
1024 struct ppp_comp_stats cstats;
1029 ppp_get_stats(ppp, &stats);
1030 if (copy_to_user(addr, &stats, sizeof(stats)))
1035 case SIOCGPPPCSTATS:
1036 memset(&cstats, 0, sizeof(cstats));
1038 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1040 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1041 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1048 if (copy_to_user(addr, vers, strlen(vers) + 1))
1060 static struct rtnl_link_stats64*
1061 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1063 struct ppp *ppp = netdev_priv(dev);
1066 stats64->rx_packets = ppp->stats64.rx_packets;
1067 stats64->rx_bytes = ppp->stats64.rx_bytes;
1068 ppp_recv_unlock(ppp);
1071 stats64->tx_packets = ppp->stats64.tx_packets;
1072 stats64->tx_bytes = ppp->stats64.tx_bytes;
1073 ppp_xmit_unlock(ppp);
1075 stats64->rx_errors = dev->stats.rx_errors;
1076 stats64->tx_errors = dev->stats.tx_errors;
1077 stats64->rx_dropped = dev->stats.rx_dropped;
1078 stats64->tx_dropped = dev->stats.tx_dropped;
1079 stats64->rx_length_errors = dev->stats.rx_length_errors;
1084 static struct lock_class_key ppp_tx_busylock;
1085 static int ppp_dev_init(struct net_device *dev)
1087 dev->qdisc_tx_busylock = &ppp_tx_busylock;
1091 static const struct net_device_ops ppp_netdev_ops = {
1092 .ndo_init = ppp_dev_init,
1093 .ndo_start_xmit = ppp_start_xmit,
1094 .ndo_do_ioctl = ppp_net_ioctl,
1095 .ndo_get_stats64 = ppp_get_stats64,
1098 static void ppp_setup(struct net_device *dev)
1100 dev->netdev_ops = &ppp_netdev_ops;
1101 dev->hard_header_len = PPP_HDRLEN;
1104 dev->tx_queue_len = 3;
1105 dev->type = ARPHRD_PPP;
1106 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1107 dev->features |= NETIF_F_NETNS_LOCAL;
1108 netif_keep_dst(dev);
1112 * Transmit-side routines.
1116 * Called to do any work queued up on the transmit side
1117 * that can now be done.
1120 ppp_xmit_process(struct ppp *ppp)
1122 struct sk_buff *skb;
1125 if (!ppp->closing) {
1127 while (!ppp->xmit_pending &&
1128 (skb = skb_dequeue(&ppp->file.xq)))
1129 ppp_send_frame(ppp, skb);
1130 /* If there's no work left to do, tell the core net
1131 code that we can accept some more. */
1132 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1133 netif_wake_queue(ppp->dev);
1135 netif_stop_queue(ppp->dev);
1137 ppp_xmit_unlock(ppp);
1140 static inline struct sk_buff *
1141 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1143 struct sk_buff *new_skb;
1145 int new_skb_size = ppp->dev->mtu +
1146 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1147 int compressor_skb_size = ppp->dev->mtu +
1148 ppp->xcomp->comp_extra + PPP_HDRLEN;
1149 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1151 if (net_ratelimit())
1152 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1155 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1156 skb_reserve(new_skb,
1157 ppp->dev->hard_header_len - PPP_HDRLEN);
1159 /* compressor still expects A/C bytes in hdr */
1160 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1161 new_skb->data, skb->len + 2,
1162 compressor_skb_size);
1163 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1167 skb_pull(skb, 2); /* pull off A/C bytes */
1168 } else if (len == 0) {
1169 /* didn't compress, or CCP not up yet */
1170 consume_skb(new_skb);
1175 * MPPE requires that we do not send unencrypted
1176 * frames. The compressor will return -1 if we
1177 * should drop the frame. We cannot simply test
1178 * the compress_proto because MPPE and MPPC share
1181 if (net_ratelimit())
1182 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1184 consume_skb(new_skb);
1191 * Compress and send a frame.
1192 * The caller should have locked the xmit path,
1193 * and xmit_pending should be 0.
1196 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1198 int proto = PPP_PROTO(skb);
1199 struct sk_buff *new_skb;
1203 if (proto < 0x8000) {
1204 #ifdef CONFIG_PPP_FILTER
1205 /* check if we should pass this packet */
1206 /* the filter instructions are constructed assuming
1207 a four-byte PPP header on each packet */
1208 *skb_push(skb, 2) = 1;
1209 if (ppp->pass_filter &&
1210 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1212 netdev_printk(KERN_DEBUG, ppp->dev,
1213 "PPP: outbound frame "
1218 /* if this packet passes the active filter, record the time */
1219 if (!(ppp->active_filter &&
1220 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1221 ppp->last_xmit = jiffies;
1224 /* for data packets, record the time */
1225 ppp->last_xmit = jiffies;
1226 #endif /* CONFIG_PPP_FILTER */
1229 ++ppp->stats64.tx_packets;
1230 ppp->stats64.tx_bytes += skb->len - 2;
1234 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1236 /* try to do VJ TCP header compression */
1237 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1240 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1243 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1245 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1246 new_skb->data + 2, &cp,
1247 !(ppp->flags & SC_NO_TCP_CCID));
1248 if (cp == skb->data + 2) {
1249 /* didn't compress */
1250 consume_skb(new_skb);
1252 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1253 proto = PPP_VJC_COMP;
1254 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1256 proto = PPP_VJC_UNCOMP;
1257 cp[0] = skb->data[2];
1261 cp = skb_put(skb, len + 2);
1268 /* peek at outbound CCP frames */
1269 ppp_ccp_peek(ppp, skb, 0);
1273 /* try to do packet compression */
1274 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1275 proto != PPP_LCP && proto != PPP_CCP) {
1276 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1277 if (net_ratelimit())
1278 netdev_err(ppp->dev,
1279 "ppp: compression required but "
1280 "down - pkt dropped.\n");
1283 skb = pad_compress_skb(ppp, skb);
1289 * If we are waiting for traffic (demand dialling),
1290 * queue it up for pppd to receive.
1292 if (ppp->flags & SC_LOOP_TRAFFIC) {
1293 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1295 skb_queue_tail(&ppp->file.rq, skb);
1296 wake_up_interruptible(&ppp->file.rwait);
1300 ppp->xmit_pending = skb;
1306 ++ppp->dev->stats.tx_errors;
1310 * Try to send the frame in xmit_pending.
1311 * The caller should have the xmit path locked.
1314 ppp_push(struct ppp *ppp)
1316 struct list_head *list;
1317 struct channel *pch;
1318 struct sk_buff *skb = ppp->xmit_pending;
1323 list = &ppp->channels;
1324 if (list_empty(list)) {
1325 /* nowhere to send the packet, just drop it */
1326 ppp->xmit_pending = NULL;
1331 if ((ppp->flags & SC_MULTILINK) == 0) {
1332 /* not doing multilink: send it down the first channel */
1334 pch = list_entry(list, struct channel, clist);
1336 spin_lock_bh(&pch->downl);
1338 if (pch->chan->ops->start_xmit(pch->chan, skb))
1339 ppp->xmit_pending = NULL;
1341 /* channel got unregistered */
1343 ppp->xmit_pending = NULL;
1345 spin_unlock_bh(&pch->downl);
1349 #ifdef CONFIG_PPP_MULTILINK
1350 /* Multilink: fragment the packet over as many links
1351 as can take the packet at the moment. */
1352 if (!ppp_mp_explode(ppp, skb))
1354 #endif /* CONFIG_PPP_MULTILINK */
1356 ppp->xmit_pending = NULL;
1360 #ifdef CONFIG_PPP_MULTILINK
1361 static bool mp_protocol_compress __read_mostly = true;
1362 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1363 MODULE_PARM_DESC(mp_protocol_compress,
1364 "compress protocol id in multilink fragments");
1367 * Divide a packet to be transmitted into fragments and
1368 * send them out the individual links.
1370 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1373 int i, bits, hdrlen, mtu;
1375 int navail, nfree, nzero;
1379 unsigned char *p, *q;
1380 struct list_head *list;
1381 struct channel *pch;
1382 struct sk_buff *frag;
1383 struct ppp_channel *chan;
1385 totspeed = 0; /*total bitrate of the bundle*/
1386 nfree = 0; /* # channels which have no packet already queued */
1387 navail = 0; /* total # of usable channels (not deregistered) */
1388 nzero = 0; /* number of channels with zero speed associated*/
1389 totfree = 0; /*total # of channels available and
1390 *having no queued packets before
1391 *starting the fragmentation*/
1393 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1395 list_for_each_entry(pch, &ppp->channels, clist) {
1399 pch->speed = pch->chan->speed;
1404 if (skb_queue_empty(&pch->file.xq) ||
1406 if (pch->speed == 0)
1409 totspeed += pch->speed;
1415 if (!pch->had_frag && i < ppp->nxchan)
1421 * Don't start sending this packet unless at least half of
1422 * the channels are free. This gives much better TCP
1423 * performance if we have a lot of channels.
1425 if (nfree == 0 || nfree < navail / 2)
1426 return 0; /* can't take now, leave it in xmit_pending */
1428 /* Do protocol field compression */
1431 if (*p == 0 && mp_protocol_compress) {
1437 nbigger = len % nfree;
1439 /* skip to the channel after the one we last used
1440 and start at that one */
1441 list = &ppp->channels;
1442 for (i = 0; i < ppp->nxchan; ++i) {
1444 if (list == &ppp->channels) {
1450 /* create a fragment for each channel */
1454 if (list == &ppp->channels) {
1458 pch = list_entry(list, struct channel, clist);
1464 * Skip this channel if it has a fragment pending already and
1465 * we haven't given a fragment to all of the free channels.
1467 if (pch->avail == 1) {
1474 /* check the channel's mtu and whether it is still attached. */
1475 spin_lock_bh(&pch->downl);
1476 if (pch->chan == NULL) {
1477 /* can't use this channel, it's being deregistered */
1478 if (pch->speed == 0)
1481 totspeed -= pch->speed;
1483 spin_unlock_bh(&pch->downl);
1494 *if the channel speed is not set divide
1495 *the packet evenly among the free channels;
1496 *otherwise divide it according to the speed
1497 *of the channel we are going to transmit on
1501 if (pch->speed == 0) {
1508 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1509 ((totspeed*totfree)/pch->speed)) - hdrlen;
1511 flen += ((totfree - nzero)*pch->speed)/totspeed;
1512 nbigger -= ((totfree - nzero)*pch->speed)/
1520 *check if we are on the last channel or
1521 *we exceded the length of the data to
1524 if ((nfree <= 0) || (flen > len))
1527 *it is not worth to tx on slow channels:
1528 *in that case from the resulting flen according to the
1529 *above formula will be equal or less than zero.
1530 *Skip the channel in this case
1534 spin_unlock_bh(&pch->downl);
1539 * hdrlen includes the 2-byte PPP protocol field, but the
1540 * MTU counts only the payload excluding the protocol field.
1541 * (RFC1661 Section 2)
1543 mtu = pch->chan->mtu - (hdrlen - 2);
1550 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1553 q = skb_put(frag, flen + hdrlen);
1555 /* make the MP header */
1556 put_unaligned_be16(PPP_MP, q);
1557 if (ppp->flags & SC_MP_XSHORTSEQ) {
1558 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1562 q[3] = ppp->nxseq >> 16;
1563 q[4] = ppp->nxseq >> 8;
1567 memcpy(q + hdrlen, p, flen);
1569 /* try to send it down the channel */
1571 if (!skb_queue_empty(&pch->file.xq) ||
1572 !chan->ops->start_xmit(chan, frag))
1573 skb_queue_tail(&pch->file.xq, frag);
1579 spin_unlock_bh(&pch->downl);
1586 spin_unlock_bh(&pch->downl);
1588 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1589 ++ppp->dev->stats.tx_errors;
1591 return 1; /* abandon the frame */
1593 #endif /* CONFIG_PPP_MULTILINK */
1596 * Try to send data out on a channel.
1599 ppp_channel_push(struct channel *pch)
1601 struct sk_buff *skb;
1604 spin_lock_bh(&pch->downl);
1606 while (!skb_queue_empty(&pch->file.xq)) {
1607 skb = skb_dequeue(&pch->file.xq);
1608 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1609 /* put the packet back and try again later */
1610 skb_queue_head(&pch->file.xq, skb);
1615 /* channel got deregistered */
1616 skb_queue_purge(&pch->file.xq);
1618 spin_unlock_bh(&pch->downl);
1619 /* see if there is anything from the attached unit to be sent */
1620 if (skb_queue_empty(&pch->file.xq)) {
1621 read_lock_bh(&pch->upl);
1624 ppp_xmit_process(ppp);
1625 read_unlock_bh(&pch->upl);
1630 * Receive-side routines.
1633 struct ppp_mp_skb_parm {
1637 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1640 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1644 ppp_receive_frame(ppp, skb, pch);
1647 ppp_recv_unlock(ppp);
1651 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1653 struct channel *pch = chan->ppp;
1661 read_lock_bh(&pch->upl);
1662 if (!pskb_may_pull(skb, 2)) {
1665 ++pch->ppp->dev->stats.rx_length_errors;
1666 ppp_receive_error(pch->ppp);
1671 proto = PPP_PROTO(skb);
1672 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1673 /* put it on the channel queue */
1674 skb_queue_tail(&pch->file.rq, skb);
1675 /* drop old frames if queue too long */
1676 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1677 (skb = skb_dequeue(&pch->file.rq)))
1679 wake_up_interruptible(&pch->file.rwait);
1681 ppp_do_recv(pch->ppp, skb, pch);
1685 read_unlock_bh(&pch->upl);
1688 /* Put a 0-length skb in the receive queue as an error indication */
1690 ppp_input_error(struct ppp_channel *chan, int code)
1692 struct channel *pch = chan->ppp;
1693 struct sk_buff *skb;
1698 read_lock_bh(&pch->upl);
1700 skb = alloc_skb(0, GFP_ATOMIC);
1702 skb->len = 0; /* probably unnecessary */
1704 ppp_do_recv(pch->ppp, skb, pch);
1707 read_unlock_bh(&pch->upl);
1711 * We come in here to process a received frame.
1712 * The receive side of the ppp unit is locked.
1715 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1717 /* note: a 0-length skb is used as an error indication */
1719 skb_checksum_complete_unset(skb);
1720 #ifdef CONFIG_PPP_MULTILINK
1721 /* XXX do channel-level decompression here */
1722 if (PPP_PROTO(skb) == PPP_MP)
1723 ppp_receive_mp_frame(ppp, skb, pch);
1725 #endif /* CONFIG_PPP_MULTILINK */
1726 ppp_receive_nonmp_frame(ppp, skb);
1729 ppp_receive_error(ppp);
1734 ppp_receive_error(struct ppp *ppp)
1736 ++ppp->dev->stats.rx_errors;
1742 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1745 int proto, len, npi;
1748 * Decompress the frame, if compressed.
1749 * Note that some decompressors need to see uncompressed frames
1750 * that come in as well as compressed frames.
1752 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1753 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1754 skb = ppp_decompress_frame(ppp, skb);
1756 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1759 proto = PPP_PROTO(skb);
1762 /* decompress VJ compressed packets */
1763 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1766 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1767 /* copy to a new sk_buff with more tailroom */
1768 ns = dev_alloc_skb(skb->len + 128);
1770 netdev_err(ppp->dev, "PPP: no memory "
1775 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1780 skb->ip_summed = CHECKSUM_NONE;
1782 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1784 netdev_printk(KERN_DEBUG, ppp->dev,
1785 "PPP: VJ decompression error\n");
1790 skb_put(skb, len - skb->len);
1791 else if (len < skb->len)
1796 case PPP_VJC_UNCOMP:
1797 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1800 /* Until we fix the decompressor need to make sure
1801 * data portion is linear.
1803 if (!pskb_may_pull(skb, skb->len))
1806 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1807 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
1814 ppp_ccp_peek(ppp, skb, 1);
1818 ++ppp->stats64.rx_packets;
1819 ppp->stats64.rx_bytes += skb->len - 2;
1821 npi = proto_to_npindex(proto);
1823 /* control or unknown frame - pass it to pppd */
1824 skb_queue_tail(&ppp->file.rq, skb);
1825 /* limit queue length by dropping old frames */
1826 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1827 (skb = skb_dequeue(&ppp->file.rq)))
1829 /* wake up any process polling or blocking on read */
1830 wake_up_interruptible(&ppp->file.rwait);
1833 /* network protocol frame - give it to the kernel */
1835 #ifdef CONFIG_PPP_FILTER
1836 /* check if the packet passes the pass and active filters */
1837 /* the filter instructions are constructed assuming
1838 a four-byte PPP header on each packet */
1839 if (ppp->pass_filter || ppp->active_filter) {
1840 if (skb_unclone(skb, GFP_ATOMIC))
1843 *skb_push(skb, 2) = 0;
1844 if (ppp->pass_filter &&
1845 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1847 netdev_printk(KERN_DEBUG, ppp->dev,
1848 "PPP: inbound frame "
1853 if (!(ppp->active_filter &&
1854 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1855 ppp->last_recv = jiffies;
1858 #endif /* CONFIG_PPP_FILTER */
1859 ppp->last_recv = jiffies;
1861 if ((ppp->dev->flags & IFF_UP) == 0 ||
1862 ppp->npmode[npi] != NPMODE_PASS) {
1865 /* chop off protocol */
1866 skb_pull_rcsum(skb, 2);
1867 skb->dev = ppp->dev;
1868 skb->protocol = htons(npindex_to_ethertype[npi]);
1869 skb_reset_mac_header(skb);
1877 ppp_receive_error(ppp);
1880 static struct sk_buff *
1881 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1883 int proto = PPP_PROTO(skb);
1887 /* Until we fix all the decompressor's need to make sure
1888 * data portion is linear.
1890 if (!pskb_may_pull(skb, skb->len))
1893 if (proto == PPP_COMP) {
1896 switch(ppp->rcomp->compress_proto) {
1898 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1901 obuff_size = ppp->mru + PPP_HDRLEN;
1905 ns = dev_alloc_skb(obuff_size);
1907 netdev_err(ppp->dev, "ppp_decompress_frame: "
1911 /* the decompressor still expects the A/C bytes in the hdr */
1912 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1913 skb->len + 2, ns->data, obuff_size);
1915 /* Pass the compressed frame to pppd as an
1916 error indication. */
1917 if (len == DECOMP_FATALERROR)
1918 ppp->rstate |= SC_DC_FERROR;
1926 skb_pull(skb, 2); /* pull off the A/C bytes */
1929 /* Uncompressed frame - pass to decompressor so it
1930 can update its dictionary if necessary. */
1931 if (ppp->rcomp->incomp)
1932 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1939 ppp->rstate |= SC_DC_ERROR;
1940 ppp_receive_error(ppp);
1944 #ifdef CONFIG_PPP_MULTILINK
1946 * Receive a multilink frame.
1947 * We put it on the reconstruction queue and then pull off
1948 * as many completed frames as we can.
1951 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1955 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1957 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1958 goto err; /* no good, throw it away */
1960 /* Decode sequence number and begin/end bits */
1961 if (ppp->flags & SC_MP_SHORTSEQ) {
1962 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1965 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1968 PPP_MP_CB(skb)->BEbits = skb->data[2];
1969 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1972 * Do protocol ID decompression on the first fragment of each packet.
1974 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
1975 *skb_push(skb, 1) = 0;
1978 * Expand sequence number to 32 bits, making it as close
1979 * as possible to ppp->minseq.
1981 seq |= ppp->minseq & ~mask;
1982 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1984 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1985 seq -= mask + 1; /* should never happen */
1986 PPP_MP_CB(skb)->sequence = seq;
1990 * If this packet comes before the next one we were expecting,
1993 if (seq_before(seq, ppp->nextseq)) {
1995 ++ppp->dev->stats.rx_dropped;
1996 ppp_receive_error(ppp);
2001 * Reevaluate minseq, the minimum over all channels of the
2002 * last sequence number received on each channel. Because of
2003 * the increasing sequence number rule, we know that any fragment
2004 * before `minseq' which hasn't arrived is never going to arrive.
2005 * The list of channels can't change because we have the receive
2006 * side of the ppp unit locked.
2008 list_for_each_entry(ch, &ppp->channels, clist) {
2009 if (seq_before(ch->lastseq, seq))
2012 if (seq_before(ppp->minseq, seq))
2015 /* Put the fragment on the reconstruction queue */
2016 ppp_mp_insert(ppp, skb);
2018 /* If the queue is getting long, don't wait any longer for packets
2019 before the start of the queue. */
2020 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2021 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2022 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2023 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2026 /* Pull completed packets off the queue and receive them. */
2027 while ((skb = ppp_mp_reconstruct(ppp))) {
2028 if (pskb_may_pull(skb, 2))
2029 ppp_receive_nonmp_frame(ppp, skb);
2031 ++ppp->dev->stats.rx_length_errors;
2033 ppp_receive_error(ppp);
2041 ppp_receive_error(ppp);
2045 * Insert a fragment on the MP reconstruction queue.
2046 * The queue is ordered by increasing sequence number.
2049 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2052 struct sk_buff_head *list = &ppp->mrq;
2053 u32 seq = PPP_MP_CB(skb)->sequence;
2055 /* N.B. we don't need to lock the list lock because we have the
2056 ppp unit receive-side lock. */
2057 skb_queue_walk(list, p) {
2058 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2061 __skb_queue_before(list, p, skb);
2065 * Reconstruct a packet from the MP fragment queue.
2066 * We go through increasing sequence numbers until we find a
2067 * complete packet, or we get to the sequence number for a fragment
2068 * which hasn't arrived but might still do so.
2070 static struct sk_buff *
2071 ppp_mp_reconstruct(struct ppp *ppp)
2073 u32 seq = ppp->nextseq;
2074 u32 minseq = ppp->minseq;
2075 struct sk_buff_head *list = &ppp->mrq;
2076 struct sk_buff *p, *tmp;
2077 struct sk_buff *head, *tail;
2078 struct sk_buff *skb = NULL;
2079 int lost = 0, len = 0;
2081 if (ppp->mrru == 0) /* do nothing until mrru is set */
2085 skb_queue_walk_safe(list, p, tmp) {
2087 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2088 /* this can't happen, anyway ignore the skb */
2089 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2091 PPP_MP_CB(p)->sequence, seq);
2092 __skb_unlink(p, list);
2096 if (PPP_MP_CB(p)->sequence != seq) {
2098 /* Fragment `seq' is missing. If it is after
2099 minseq, it might arrive later, so stop here. */
2100 if (seq_after(seq, minseq))
2102 /* Fragment `seq' is lost, keep going. */
2105 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2106 minseq + 1: PPP_MP_CB(p)->sequence;
2109 netdev_printk(KERN_DEBUG, ppp->dev,
2110 "lost frag %u..%u\n",
2117 * At this point we know that all the fragments from
2118 * ppp->nextseq to seq are either present or lost.
2119 * Also, there are no complete packets in the queue
2120 * that have no missing fragments and end before this
2124 /* B bit set indicates this fragment starts a packet */
2125 if (PPP_MP_CB(p)->BEbits & B) {
2133 /* Got a complete packet yet? */
2134 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2135 (PPP_MP_CB(head)->BEbits & B)) {
2136 if (len > ppp->mrru + 2) {
2137 ++ppp->dev->stats.rx_length_errors;
2138 netdev_printk(KERN_DEBUG, ppp->dev,
2139 "PPP: reconstructed packet"
2140 " is too long (%d)\n", len);
2145 ppp->nextseq = seq + 1;
2149 * If this is the ending fragment of a packet,
2150 * and we haven't found a complete valid packet yet,
2151 * we can discard up to and including this fragment.
2153 if (PPP_MP_CB(p)->BEbits & E) {
2154 struct sk_buff *tmp2;
2156 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2158 netdev_printk(KERN_DEBUG, ppp->dev,
2159 "discarding frag %u\n",
2160 PPP_MP_CB(p)->sequence);
2161 __skb_unlink(p, list);
2164 head = skb_peek(list);
2171 /* If we have a complete packet, copy it all into one skb. */
2173 /* If we have discarded any fragments,
2174 signal a receive error. */
2175 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2176 skb_queue_walk_safe(list, p, tmp) {
2180 netdev_printk(KERN_DEBUG, ppp->dev,
2181 "discarding frag %u\n",
2182 PPP_MP_CB(p)->sequence);
2183 __skb_unlink(p, list);
2188 netdev_printk(KERN_DEBUG, ppp->dev,
2189 " missed pkts %u..%u\n",
2191 PPP_MP_CB(head)->sequence-1);
2192 ++ppp->dev->stats.rx_dropped;
2193 ppp_receive_error(ppp);
2198 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2199 p = skb_queue_next(list, head);
2200 __skb_unlink(skb, list);
2201 skb_queue_walk_from_safe(list, p, tmp) {
2202 __skb_unlink(p, list);
2208 skb->data_len += p->len;
2209 skb->truesize += p->truesize;
2215 __skb_unlink(skb, list);
2218 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2223 #endif /* CONFIG_PPP_MULTILINK */
2226 * Channel interface.
2229 /* Create a new, unattached ppp channel. */
2230 int ppp_register_channel(struct ppp_channel *chan)
2232 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2235 /* Create a new, unattached ppp channel for specified net. */
2236 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2238 struct channel *pch;
2241 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2245 pn = ppp_pernet(net);
2249 pch->chan_net = net;
2251 init_ppp_file(&pch->file, CHANNEL);
2252 pch->file.hdrlen = chan->hdrlen;
2253 #ifdef CONFIG_PPP_MULTILINK
2255 #endif /* CONFIG_PPP_MULTILINK */
2256 init_rwsem(&pch->chan_sem);
2257 spin_lock_init(&pch->downl);
2258 rwlock_init(&pch->upl);
2260 spin_lock_bh(&pn->all_channels_lock);
2261 pch->file.index = ++pn->last_channel_index;
2262 list_add(&pch->list, &pn->new_channels);
2263 atomic_inc(&channel_count);
2264 spin_unlock_bh(&pn->all_channels_lock);
2270 * Return the index of a channel.
2272 int ppp_channel_index(struct ppp_channel *chan)
2274 struct channel *pch = chan->ppp;
2277 return pch->file.index;
2282 * Return the PPP unit number to which a channel is connected.
2284 int ppp_unit_number(struct ppp_channel *chan)
2286 struct channel *pch = chan->ppp;
2290 read_lock_bh(&pch->upl);
2292 unit = pch->ppp->file.index;
2293 read_unlock_bh(&pch->upl);
2299 * Return the PPP device interface name of a channel.
2301 char *ppp_dev_name(struct ppp_channel *chan)
2303 struct channel *pch = chan->ppp;
2307 read_lock_bh(&pch->upl);
2308 if (pch->ppp && pch->ppp->dev)
2309 name = pch->ppp->dev->name;
2310 read_unlock_bh(&pch->upl);
2317 * Disconnect a channel from the generic layer.
2318 * This must be called in process context.
2321 ppp_unregister_channel(struct ppp_channel *chan)
2323 struct channel *pch = chan->ppp;
2327 return; /* should never happen */
2332 * This ensures that we have returned from any calls into the
2333 * the channel's start_xmit or ioctl routine before we proceed.
2335 down_write(&pch->chan_sem);
2336 spin_lock_bh(&pch->downl);
2338 spin_unlock_bh(&pch->downl);
2339 up_write(&pch->chan_sem);
2340 ppp_disconnect_channel(pch);
2342 pn = ppp_pernet(pch->chan_net);
2343 spin_lock_bh(&pn->all_channels_lock);
2344 list_del(&pch->list);
2345 spin_unlock_bh(&pn->all_channels_lock);
2348 wake_up_interruptible(&pch->file.rwait);
2349 if (atomic_dec_and_test(&pch->file.refcnt))
2350 ppp_destroy_channel(pch);
2354 * Callback from a channel when it can accept more to transmit.
2355 * This should be called at BH/softirq level, not interrupt level.
2358 ppp_output_wakeup(struct ppp_channel *chan)
2360 struct channel *pch = chan->ppp;
2364 ppp_channel_push(pch);
2368 * Compression control.
2371 /* Process the PPPIOCSCOMPRESS ioctl. */
2373 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2376 struct compressor *cp, *ocomp;
2377 struct ppp_option_data data;
2378 void *state, *ostate;
2379 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2382 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2383 (data.length <= CCP_MAX_OPTION_LENGTH &&
2384 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2387 if (data.length > CCP_MAX_OPTION_LENGTH ||
2388 ccp_option[1] < 2 || ccp_option[1] > data.length)
2391 cp = try_then_request_module(
2392 find_compressor(ccp_option[0]),
2393 "ppp-compress-%d", ccp_option[0]);
2398 if (data.transmit) {
2399 state = cp->comp_alloc(ccp_option, data.length);
2402 ppp->xstate &= ~SC_COMP_RUN;
2404 ostate = ppp->xc_state;
2406 ppp->xc_state = state;
2407 ppp_xmit_unlock(ppp);
2409 ocomp->comp_free(ostate);
2410 module_put(ocomp->owner);
2414 module_put(cp->owner);
2417 state = cp->decomp_alloc(ccp_option, data.length);
2420 ppp->rstate &= ~SC_DECOMP_RUN;
2422 ostate = ppp->rc_state;
2424 ppp->rc_state = state;
2425 ppp_recv_unlock(ppp);
2427 ocomp->decomp_free(ostate);
2428 module_put(ocomp->owner);
2432 module_put(cp->owner);
2440 * Look at a CCP packet and update our state accordingly.
2441 * We assume the caller has the xmit or recv path locked.
2444 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2449 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2450 return; /* no header */
2453 switch (CCP_CODE(dp)) {
2456 /* A ConfReq starts negotiation of compression
2457 * in one direction of transmission,
2458 * and hence brings it down...but which way?
2461 * A ConfReq indicates what the sender would like to receive
2464 /* He is proposing what I should send */
2465 ppp->xstate &= ~SC_COMP_RUN;
2467 /* I am proposing to what he should send */
2468 ppp->rstate &= ~SC_DECOMP_RUN;
2475 * CCP is going down, both directions of transmission
2477 ppp->rstate &= ~SC_DECOMP_RUN;
2478 ppp->xstate &= ~SC_COMP_RUN;
2482 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2484 len = CCP_LENGTH(dp);
2485 if (!pskb_may_pull(skb, len + 2))
2486 return; /* too short */
2489 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2492 /* we will start receiving compressed packets */
2495 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2496 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2497 ppp->rstate |= SC_DECOMP_RUN;
2498 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2501 /* we will soon start sending compressed packets */
2504 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2505 ppp->file.index, 0, ppp->debug))
2506 ppp->xstate |= SC_COMP_RUN;
2511 /* reset the [de]compressor */
2512 if ((ppp->flags & SC_CCP_UP) == 0)
2515 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2516 ppp->rcomp->decomp_reset(ppp->rc_state);
2517 ppp->rstate &= ~SC_DC_ERROR;
2520 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2521 ppp->xcomp->comp_reset(ppp->xc_state);
2527 /* Free up compression resources. */
2529 ppp_ccp_closed(struct ppp *ppp)
2531 void *xstate, *rstate;
2532 struct compressor *xcomp, *rcomp;
2535 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2538 xstate = ppp->xc_state;
2539 ppp->xc_state = NULL;
2542 rstate = ppp->rc_state;
2543 ppp->rc_state = NULL;
2547 xcomp->comp_free(xstate);
2548 module_put(xcomp->owner);
2551 rcomp->decomp_free(rstate);
2552 module_put(rcomp->owner);
2556 /* List of compressors. */
2557 static LIST_HEAD(compressor_list);
2558 static DEFINE_SPINLOCK(compressor_list_lock);
2560 struct compressor_entry {
2561 struct list_head list;
2562 struct compressor *comp;
2565 static struct compressor_entry *
2566 find_comp_entry(int proto)
2568 struct compressor_entry *ce;
2570 list_for_each_entry(ce, &compressor_list, list) {
2571 if (ce->comp->compress_proto == proto)
2577 /* Register a compressor */
2579 ppp_register_compressor(struct compressor *cp)
2581 struct compressor_entry *ce;
2583 spin_lock(&compressor_list_lock);
2585 if (find_comp_entry(cp->compress_proto))
2588 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2593 list_add(&ce->list, &compressor_list);
2595 spin_unlock(&compressor_list_lock);
2599 /* Unregister a compressor */
2601 ppp_unregister_compressor(struct compressor *cp)
2603 struct compressor_entry *ce;
2605 spin_lock(&compressor_list_lock);
2606 ce = find_comp_entry(cp->compress_proto);
2607 if (ce && ce->comp == cp) {
2608 list_del(&ce->list);
2611 spin_unlock(&compressor_list_lock);
2614 /* Find a compressor. */
2615 static struct compressor *
2616 find_compressor(int type)
2618 struct compressor_entry *ce;
2619 struct compressor *cp = NULL;
2621 spin_lock(&compressor_list_lock);
2622 ce = find_comp_entry(type);
2625 if (!try_module_get(cp->owner))
2628 spin_unlock(&compressor_list_lock);
2633 * Miscelleneous stuff.
2637 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2639 struct slcompress *vj = ppp->vj;
2641 memset(st, 0, sizeof(*st));
2642 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2643 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2644 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2645 st->p.ppp_opackets = ppp->stats64.tx_packets;
2646 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2647 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2650 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2651 st->vj.vjs_compressed = vj->sls_o_compressed;
2652 st->vj.vjs_searches = vj->sls_o_searches;
2653 st->vj.vjs_misses = vj->sls_o_misses;
2654 st->vj.vjs_errorin = vj->sls_i_error;
2655 st->vj.vjs_tossed = vj->sls_i_tossed;
2656 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2657 st->vj.vjs_compressedin = vj->sls_i_compressed;
2661 * Stuff for handling the lists of ppp units and channels
2662 * and for initialization.
2666 * Create a new ppp interface unit. Fails if it can't allocate memory
2667 * or if there is already a unit with the requested number.
2668 * unit == -1 means allocate a new number.
2671 ppp_create_interface(struct net *net, int unit, int *retp)
2675 struct net_device *dev = NULL;
2679 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN,
2684 pn = ppp_pernet(net);
2686 ppp = netdev_priv(dev);
2689 init_ppp_file(&ppp->file, INTERFACE);
2690 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2691 for (i = 0; i < NUM_NP; ++i)
2692 ppp->npmode[i] = NPMODE_PASS;
2693 INIT_LIST_HEAD(&ppp->channels);
2694 spin_lock_init(&ppp->rlock);
2695 spin_lock_init(&ppp->wlock);
2696 #ifdef CONFIG_PPP_MULTILINK
2698 skb_queue_head_init(&ppp->mrq);
2699 #endif /* CONFIG_PPP_MULTILINK */
2700 #ifdef CONFIG_PPP_FILTER
2701 ppp->pass_filter = NULL;
2702 ppp->active_filter = NULL;
2703 #endif /* CONFIG_PPP_FILTER */
2706 * drum roll: don't forget to set
2707 * the net device is belong to
2709 dev_net_set(dev, net);
2711 mutex_lock(&pn->all_ppp_mutex);
2714 unit = unit_get(&pn->units_idr, ppp);
2721 if (unit_find(&pn->units_idr, unit))
2722 goto out2; /* unit already exists */
2724 * if caller need a specified unit number
2725 * lets try to satisfy him, otherwise --
2726 * he should better ask us for new unit number
2728 * NOTE: yes I know that returning EEXIST it's not
2729 * fair but at least pppd will ask us to allocate
2730 * new unit in this case so user is happy :)
2732 unit = unit_set(&pn->units_idr, ppp, unit);
2737 /* Initialize the new ppp unit */
2738 ppp->file.index = unit;
2739 sprintf(dev->name, "ppp%d", unit);
2741 ret = register_netdev(dev);
2743 unit_put(&pn->units_idr, unit);
2744 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
2751 atomic_inc(&ppp_unit_count);
2752 mutex_unlock(&pn->all_ppp_mutex);
2758 mutex_unlock(&pn->all_ppp_mutex);
2766 * Initialize a ppp_file structure.
2769 init_ppp_file(struct ppp_file *pf, int kind)
2772 skb_queue_head_init(&pf->xq);
2773 skb_queue_head_init(&pf->rq);
2774 atomic_set(&pf->refcnt, 1);
2775 init_waitqueue_head(&pf->rwait);
2779 * Take down a ppp interface unit - called when the owning file
2780 * (the one that created the unit) is closed or detached.
2782 static void ppp_shutdown_interface(struct ppp *ppp)
2786 pn = ppp_pernet(ppp->ppp_net);
2787 mutex_lock(&pn->all_ppp_mutex);
2789 /* This will call dev_close() for us. */
2791 if (!ppp->closing) {
2794 unregister_netdev(ppp->dev);
2795 unit_put(&pn->units_idr, ppp->file.index);
2801 wake_up_interruptible(&ppp->file.rwait);
2803 mutex_unlock(&pn->all_ppp_mutex);
2807 * Free the memory used by a ppp unit. This is only called once
2808 * there are no channels connected to the unit and no file structs
2809 * that reference the unit.
2811 static void ppp_destroy_interface(struct ppp *ppp)
2813 atomic_dec(&ppp_unit_count);
2815 if (!ppp->file.dead || ppp->n_channels) {
2816 /* "can't happen" */
2817 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
2818 "but dead=%d n_channels=%d !\n",
2819 ppp, ppp->file.dead, ppp->n_channels);
2823 ppp_ccp_closed(ppp);
2828 skb_queue_purge(&ppp->file.xq);
2829 skb_queue_purge(&ppp->file.rq);
2830 #ifdef CONFIG_PPP_MULTILINK
2831 skb_queue_purge(&ppp->mrq);
2832 #endif /* CONFIG_PPP_MULTILINK */
2833 #ifdef CONFIG_PPP_FILTER
2834 if (ppp->pass_filter) {
2835 bpf_prog_destroy(ppp->pass_filter);
2836 ppp->pass_filter = NULL;
2839 if (ppp->active_filter) {
2840 bpf_prog_destroy(ppp->active_filter);
2841 ppp->active_filter = NULL;
2843 #endif /* CONFIG_PPP_FILTER */
2845 kfree_skb(ppp->xmit_pending);
2847 free_netdev(ppp->dev);
2851 * Locate an existing ppp unit.
2852 * The caller should have locked the all_ppp_mutex.
2855 ppp_find_unit(struct ppp_net *pn, int unit)
2857 return unit_find(&pn->units_idr, unit);
2861 * Locate an existing ppp channel.
2862 * The caller should have locked the all_channels_lock.
2863 * First we look in the new_channels list, then in the
2864 * all_channels list. If found in the new_channels list,
2865 * we move it to the all_channels list. This is for speed
2866 * when we have a lot of channels in use.
2868 static struct channel *
2869 ppp_find_channel(struct ppp_net *pn, int unit)
2871 struct channel *pch;
2873 list_for_each_entry(pch, &pn->new_channels, list) {
2874 if (pch->file.index == unit) {
2875 list_move(&pch->list, &pn->all_channels);
2880 list_for_each_entry(pch, &pn->all_channels, list) {
2881 if (pch->file.index == unit)
2889 * Connect a PPP channel to a PPP interface unit.
2892 ppp_connect_channel(struct channel *pch, int unit)
2899 pn = ppp_pernet(pch->chan_net);
2901 mutex_lock(&pn->all_ppp_mutex);
2902 ppp = ppp_find_unit(pn, unit);
2905 write_lock_bh(&pch->upl);
2911 if (pch->file.hdrlen > ppp->file.hdrlen)
2912 ppp->file.hdrlen = pch->file.hdrlen;
2913 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2914 if (hdrlen > ppp->dev->hard_header_len)
2915 ppp->dev->hard_header_len = hdrlen;
2916 list_add_tail(&pch->clist, &ppp->channels);
2919 atomic_inc(&ppp->file.refcnt);
2924 write_unlock_bh(&pch->upl);
2926 mutex_unlock(&pn->all_ppp_mutex);
2931 * Disconnect a channel from its ppp unit.
2934 ppp_disconnect_channel(struct channel *pch)
2939 write_lock_bh(&pch->upl);
2942 write_unlock_bh(&pch->upl);
2944 /* remove it from the ppp unit's list */
2946 list_del(&pch->clist);
2947 if (--ppp->n_channels == 0)
2948 wake_up_interruptible(&ppp->file.rwait);
2950 if (atomic_dec_and_test(&ppp->file.refcnt))
2951 ppp_destroy_interface(ppp);
2958 * Free up the resources used by a ppp channel.
2960 static void ppp_destroy_channel(struct channel *pch)
2962 atomic_dec(&channel_count);
2964 if (!pch->file.dead) {
2965 /* "can't happen" */
2966 pr_err("ppp: destroying undead channel %p !\n", pch);
2969 skb_queue_purge(&pch->file.xq);
2970 skb_queue_purge(&pch->file.rq);
2974 static void __exit ppp_cleanup(void)
2976 /* should never happen */
2977 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2978 pr_err("PPP: removing module but units remain!\n");
2979 unregister_chrdev(PPP_MAJOR, "ppp");
2980 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2981 class_destroy(ppp_class);
2982 unregister_pernet_device(&ppp_net_ops);
2986 * Units handling. Caller must protect concurrent access
2987 * by holding all_ppp_mutex
2990 /* associate pointer with specified number */
2991 static int unit_set(struct idr *p, void *ptr, int n)
2995 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
2996 if (unit == -ENOSPC)
3001 /* get new free unit number and associate pointer with it */
3002 static int unit_get(struct idr *p, void *ptr)
3004 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3007 /* put unit number back to a pool */
3008 static void unit_put(struct idr *p, int n)
3013 /* get pointer associated with the number */
3014 static void *unit_find(struct idr *p, int n)
3016 return idr_find(p, n);
3019 /* Module/initialization stuff */
3021 module_init(ppp_init);
3022 module_exit(ppp_cleanup);
3024 EXPORT_SYMBOL(ppp_register_net_channel);
3025 EXPORT_SYMBOL(ppp_register_channel);
3026 EXPORT_SYMBOL(ppp_unregister_channel);
3027 EXPORT_SYMBOL(ppp_channel_index);
3028 EXPORT_SYMBOL(ppp_unit_number);
3029 EXPORT_SYMBOL(ppp_dev_name);
3030 EXPORT_SYMBOL(ppp_input);
3031 EXPORT_SYMBOL(ppp_input_error);
3032 EXPORT_SYMBOL(ppp_output_wakeup);
3033 EXPORT_SYMBOL(ppp_register_compressor);
3034 EXPORT_SYMBOL(ppp_unregister_compressor);
3035 MODULE_LICENSE("GPL");
3036 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3037 MODULE_ALIAS("devname:ppp");