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/sched/signal.h>
28 #include <linux/kmod.h>
29 #include <linux/init.h>
30 #include <linux/list.h>
31 #include <linux/idr.h>
32 #include <linux/netdevice.h>
33 #include <linux/poll.h>
34 #include <linux/ppp_defs.h>
35 #include <linux/filter.h>
36 #include <linux/ppp-ioctl.h>
37 #include <linux/ppp_channel.h>
38 #include <linux/ppp-comp.h>
39 #include <linux/skbuff.h>
40 #include <linux/rtnetlink.h>
41 #include <linux/if_arp.h>
43 #include <linux/tcp.h>
44 #include <linux/spinlock.h>
45 #include <linux/rwsem.h>
46 #include <linux/stddef.h>
47 #include <linux/device.h>
48 #include <linux/mutex.h>
49 #include <linux/slab.h>
50 #include <linux/file.h>
51 #include <asm/unaligned.h>
52 #include <net/slhc_vj.h>
53 #include <linux/atomic.h>
55 #include <linux/nsproxy.h>
56 #include <net/net_namespace.h>
57 #include <net/netns/generic.h>
59 #define PPP_VERSION "2.4.2"
62 * Network protocols we support.
64 #define NP_IP 0 /* Internet Protocol V4 */
65 #define NP_IPV6 1 /* Internet Protocol V6 */
66 #define NP_IPX 2 /* IPX protocol */
67 #define NP_AT 3 /* Appletalk protocol */
68 #define NP_MPLS_UC 4 /* MPLS unicast */
69 #define NP_MPLS_MC 5 /* MPLS multicast */
70 #define NUM_NP 6 /* Number of NPs. */
72 #define MPHDRLEN 6 /* multilink protocol header length */
73 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
76 * An instance of /dev/ppp can be associated with either a ppp
77 * interface unit or a ppp channel. In both cases, file->private_data
78 * points to one of these.
84 struct sk_buff_head xq; /* pppd transmit queue */
85 struct sk_buff_head rq; /* receive queue for pppd */
86 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
87 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
88 int hdrlen; /* space to leave for headers */
89 int index; /* interface unit / channel number */
90 int dead; /* unit/channel has been shut down */
93 #define PF_TO_X(pf, X) container_of(pf, X, file)
95 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
96 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
99 * Data structure to hold primary network stats for which
100 * we want to use 64 bit storage. Other network stats
101 * are stored in dev->stats of the ppp strucute.
103 struct ppp_link_stats {
111 * Data structure describing one ppp unit.
112 * A ppp unit corresponds to a ppp network interface device
113 * and represents a multilink bundle.
114 * It can have 0 or more ppp channels connected to it.
117 struct ppp_file file; /* stuff for read/write/poll 0 */
118 struct file *owner; /* file that owns this unit 48 */
119 struct list_head channels; /* list of attached channels 4c */
120 int n_channels; /* how many channels are attached 54 */
121 spinlock_t rlock; /* lock for receive side 58 */
122 spinlock_t wlock; /* lock for transmit side 5c */
123 int __percpu *xmit_recursion; /* xmit recursion detect */
124 int mru; /* max receive unit 60 */
125 unsigned int flags; /* control bits 64 */
126 unsigned int xstate; /* transmit state bits 68 */
127 unsigned int rstate; /* receive state bits 6c */
128 int debug; /* debug flags 70 */
129 struct slcompress *vj; /* state for VJ header compression */
130 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
131 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
132 struct compressor *xcomp; /* transmit packet compressor 8c */
133 void *xc_state; /* its internal state 90 */
134 struct compressor *rcomp; /* receive decompressor 94 */
135 void *rc_state; /* its internal state 98 */
136 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
137 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
138 struct net_device *dev; /* network interface device a4 */
139 int closing; /* is device closing down? a8 */
140 #ifdef CONFIG_PPP_MULTILINK
141 int nxchan; /* next channel to send something on */
142 u32 nxseq; /* next sequence number to send */
143 int mrru; /* MP: max reconst. receive unit */
144 u32 nextseq; /* MP: seq no of next packet */
145 u32 minseq; /* MP: min of most recent seqnos */
146 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
147 #endif /* CONFIG_PPP_MULTILINK */
148 #ifdef CONFIG_PPP_FILTER
149 struct bpf_prog *pass_filter; /* filter for packets to pass */
150 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
151 #endif /* CONFIG_PPP_FILTER */
152 struct net *ppp_net; /* the net we belong to */
153 struct ppp_link_stats stats64; /* 64 bit network stats */
157 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
158 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
160 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
161 * Bits in xstate: SC_COMP_RUN
163 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
164 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
165 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
168 * Private data structure for each channel.
169 * This includes the data structure used for multilink.
172 struct ppp_file file; /* stuff for read/write/poll */
173 struct list_head list; /* link in all/new_channels list */
174 struct ppp_channel *chan; /* public channel data structure */
175 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
176 spinlock_t downl; /* protects `chan', file.xq dequeue */
177 struct ppp *ppp; /* ppp unit we're connected to */
178 struct net *chan_net; /* the net channel belongs to */
179 struct list_head clist; /* link in list of channels per unit */
180 rwlock_t upl; /* protects `ppp' */
181 #ifdef CONFIG_PPP_MULTILINK
182 u8 avail; /* flag used in multilink stuff */
183 u8 had_frag; /* >= 1 fragments have been sent */
184 u32 lastseq; /* MP: last sequence # received */
185 int speed; /* speed of the corresponding ppp channel*/
186 #endif /* CONFIG_PPP_MULTILINK */
196 * SMP locking issues:
197 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
198 * list and the ppp.n_channels field, you need to take both locks
199 * before you modify them.
200 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
204 static DEFINE_MUTEX(ppp_mutex);
205 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
206 static atomic_t channel_count = ATOMIC_INIT(0);
208 /* per-net private data for this module */
209 static unsigned int ppp_net_id __read_mostly;
211 /* units to ppp mapping */
212 struct idr units_idr;
215 * all_ppp_mutex protects the units_idr mapping.
216 * It also ensures that finding a ppp unit in the units_idr
217 * map and updating its file.refcnt field is atomic.
219 struct mutex all_ppp_mutex;
222 struct list_head all_channels;
223 struct list_head new_channels;
224 int last_channel_index;
227 * all_channels_lock protects all_channels and
228 * last_channel_index, and the atomicity of find
229 * a channel and updating its file.refcnt field.
231 spinlock_t all_channels_lock;
234 /* Get the PPP protocol number from a skb */
235 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
237 /* We limit the length of ppp->file.rq to this (arbitrary) value */
238 #define PPP_MAX_RQLEN 32
241 * Maximum number of multilink fragments queued up.
242 * This has to be large enough to cope with the maximum latency of
243 * the slowest channel relative to the others. Strictly it should
244 * depend on the number of channels and their characteristics.
246 #define PPP_MP_MAX_QLEN 128
248 /* Multilink header bits. */
249 #define B 0x80 /* this fragment begins a packet */
250 #define E 0x40 /* this fragment ends a packet */
252 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
253 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
254 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
257 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
258 struct file *file, unsigned int cmd, unsigned long arg);
259 static void ppp_xmit_process(struct ppp *ppp);
260 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
261 static void ppp_push(struct ppp *ppp);
262 static void ppp_channel_push(struct channel *pch);
263 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
264 struct channel *pch);
265 static void ppp_receive_error(struct ppp *ppp);
266 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
267 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
268 struct sk_buff *skb);
269 #ifdef CONFIG_PPP_MULTILINK
270 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
271 struct channel *pch);
272 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
273 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
274 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
275 #endif /* CONFIG_PPP_MULTILINK */
276 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
277 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
278 static void ppp_ccp_closed(struct ppp *ppp);
279 static struct compressor *find_compressor(int type);
280 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
281 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
282 static void init_ppp_file(struct ppp_file *pf, int kind);
283 static void ppp_destroy_interface(struct ppp *ppp);
284 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
285 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
286 static int ppp_connect_channel(struct channel *pch, int unit);
287 static int ppp_disconnect_channel(struct channel *pch);
288 static void ppp_destroy_channel(struct channel *pch);
289 static int unit_get(struct idr *p, void *ptr);
290 static int unit_set(struct idr *p, void *ptr, int n);
291 static void unit_put(struct idr *p, int n);
292 static void *unit_find(struct idr *p, int n);
293 static void ppp_setup(struct net_device *dev);
295 static const struct net_device_ops ppp_netdev_ops;
297 static struct class *ppp_class;
299 /* per net-namespace data */
300 static inline struct ppp_net *ppp_pernet(struct net *net)
304 return net_generic(net, ppp_net_id);
307 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
308 static inline int proto_to_npindex(int proto)
327 /* Translates an NP index into a PPP protocol number */
328 static const int npindex_to_proto[NUM_NP] = {
337 /* Translates an ethertype into an NP index */
338 static inline int ethertype_to_npindex(int ethertype)
358 /* Translates an NP index into an ethertype */
359 static const int npindex_to_ethertype[NUM_NP] = {
371 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
372 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
373 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
374 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
375 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
376 ppp_recv_lock(ppp); } while (0)
377 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
378 ppp_xmit_unlock(ppp); } while (0)
381 * /dev/ppp device routines.
382 * The /dev/ppp device is used by pppd to control the ppp unit.
383 * It supports the read, write, ioctl and poll functions.
384 * Open instances of /dev/ppp can be in one of three states:
385 * unattached, attached to a ppp unit, or attached to a ppp channel.
387 static int ppp_open(struct inode *inode, struct file *file)
390 * This could (should?) be enforced by the permissions on /dev/ppp.
392 if (!capable(CAP_NET_ADMIN))
397 static int ppp_release(struct inode *unused, struct file *file)
399 struct ppp_file *pf = file->private_data;
403 file->private_data = NULL;
404 if (pf->kind == INTERFACE) {
407 if (file == ppp->owner)
408 unregister_netdevice(ppp->dev);
411 if (atomic_dec_and_test(&pf->refcnt)) {
414 ppp_destroy_interface(PF_TO_PPP(pf));
417 ppp_destroy_channel(PF_TO_CHANNEL(pf));
425 static ssize_t ppp_read(struct file *file, char __user *buf,
426 size_t count, loff_t *ppos)
428 struct ppp_file *pf = file->private_data;
429 DECLARE_WAITQUEUE(wait, current);
431 struct sk_buff *skb = NULL;
439 add_wait_queue(&pf->rwait, &wait);
441 set_current_state(TASK_INTERRUPTIBLE);
442 skb = skb_dequeue(&pf->rq);
448 if (pf->kind == INTERFACE) {
450 * Return 0 (EOF) on an interface that has no
451 * channels connected, unless it is looping
452 * network traffic (demand mode).
454 struct ppp *ppp = PF_TO_PPP(pf);
457 if (ppp->n_channels == 0 &&
458 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
459 ppp_recv_unlock(ppp);
462 ppp_recv_unlock(ppp);
465 if (file->f_flags & O_NONBLOCK)
468 if (signal_pending(current))
472 set_current_state(TASK_RUNNING);
473 remove_wait_queue(&pf->rwait, &wait);
479 if (skb->len > count)
484 iov_iter_init(&to, READ, &iov, 1, count);
485 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
495 static ssize_t ppp_write(struct file *file, const char __user *buf,
496 size_t count, loff_t *ppos)
498 struct ppp_file *pf = file->private_data;
505 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
508 skb_reserve(skb, pf->hdrlen);
510 if (copy_from_user(skb_put(skb, count), buf, count)) {
515 skb_queue_tail(&pf->xq, skb);
519 ppp_xmit_process(PF_TO_PPP(pf));
522 ppp_channel_push(PF_TO_CHANNEL(pf));
532 /* No kernel lock - fine */
533 static unsigned int ppp_poll(struct file *file, poll_table *wait)
535 struct ppp_file *pf = file->private_data;
540 poll_wait(file, &pf->rwait, wait);
541 mask = POLLOUT | POLLWRNORM;
542 if (skb_peek(&pf->rq))
543 mask |= POLLIN | POLLRDNORM;
546 else if (pf->kind == INTERFACE) {
547 /* see comment in ppp_read */
548 struct ppp *ppp = PF_TO_PPP(pf);
551 if (ppp->n_channels == 0 &&
552 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
553 mask |= POLLIN | POLLRDNORM;
554 ppp_recv_unlock(ppp);
560 #ifdef CONFIG_PPP_FILTER
561 static int get_filter(void __user *arg, struct sock_filter **p)
563 struct sock_fprog uprog;
564 struct sock_filter *code = NULL;
567 if (copy_from_user(&uprog, arg, sizeof(uprog)))
575 len = uprog.len * sizeof(struct sock_filter);
576 code = memdup_user(uprog.filter, len);
578 return PTR_ERR(code);
583 #endif /* CONFIG_PPP_FILTER */
585 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
589 int err = -EFAULT, val, val2, i;
590 struct ppp_idle idle;
593 struct slcompress *vj;
594 void __user *argp = (void __user *)arg;
595 int __user *p = argp;
597 mutex_lock(&ppp_mutex);
599 pf = file->private_data;
601 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
606 if (cmd == PPPIOCDETACH) {
608 * We have to be careful here... if the file descriptor
609 * has been dup'd, we could have another process in the
610 * middle of a poll using the same file *, so we had
611 * better not free the interface data structures -
612 * instead we fail the ioctl. Even in this case, we
613 * shut down the interface if we are the owner of it.
614 * Actually, we should get rid of PPPIOCDETACH, userland
615 * (i.e. pppd) could achieve the same effect by closing
616 * this fd and reopening /dev/ppp.
619 if (pf->kind == INTERFACE) {
622 if (file == ppp->owner)
623 unregister_netdevice(ppp->dev);
626 if (atomic_long_read(&file->f_count) < 2) {
627 ppp_release(NULL, file);
630 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
631 atomic_long_read(&file->f_count));
635 if (pf->kind == CHANNEL) {
637 struct ppp_channel *chan;
639 pch = PF_TO_CHANNEL(pf);
643 if (get_user(unit, p))
645 err = ppp_connect_channel(pch, unit);
649 err = ppp_disconnect_channel(pch);
653 down_read(&pch->chan_sem);
656 if (chan && chan->ops->ioctl)
657 err = chan->ops->ioctl(chan, cmd, arg);
658 up_read(&pch->chan_sem);
663 if (pf->kind != INTERFACE) {
665 pr_err("PPP: not interface or channel??\n");
673 if (get_user(val, p))
680 if (get_user(val, p))
683 cflags = ppp->flags & ~val;
684 #ifdef CONFIG_PPP_MULTILINK
685 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
688 ppp->flags = val & SC_FLAG_BITS;
690 if (cflags & SC_CCP_OPEN)
696 val = ppp->flags | ppp->xstate | ppp->rstate;
697 if (put_user(val, p))
702 case PPPIOCSCOMPRESS:
703 err = ppp_set_compress(ppp, arg);
707 if (put_user(ppp->file.index, p))
713 if (get_user(val, p))
720 if (put_user(ppp->debug, p))
726 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
727 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
728 if (copy_to_user(argp, &idle, sizeof(idle)))
734 if (get_user(val, p))
737 if ((val >> 16) != 0) {
741 vj = slhc_init(val2+1, val+1);
756 if (copy_from_user(&npi, argp, sizeof(npi)))
758 err = proto_to_npindex(npi.protocol);
762 if (cmd == PPPIOCGNPMODE) {
764 npi.mode = ppp->npmode[i];
765 if (copy_to_user(argp, &npi, sizeof(npi)))
768 ppp->npmode[i] = npi.mode;
769 /* we may be able to transmit more packets now (??) */
770 netif_wake_queue(ppp->dev);
775 #ifdef CONFIG_PPP_FILTER
778 struct sock_filter *code;
780 err = get_filter(argp, &code);
782 struct bpf_prog *pass_filter = NULL;
783 struct sock_fprog_kern fprog = {
790 err = bpf_prog_create(&pass_filter, &fprog);
793 if (ppp->pass_filter)
794 bpf_prog_destroy(ppp->pass_filter);
795 ppp->pass_filter = pass_filter;
804 struct sock_filter *code;
806 err = get_filter(argp, &code);
808 struct bpf_prog *active_filter = NULL;
809 struct sock_fprog_kern fprog = {
816 err = bpf_prog_create(&active_filter, &fprog);
819 if (ppp->active_filter)
820 bpf_prog_destroy(ppp->active_filter);
821 ppp->active_filter = active_filter;
828 #endif /* CONFIG_PPP_FILTER */
830 #ifdef CONFIG_PPP_MULTILINK
832 if (get_user(val, p))
836 ppp_recv_unlock(ppp);
839 #endif /* CONFIG_PPP_MULTILINK */
846 mutex_unlock(&ppp_mutex);
851 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
852 struct file *file, unsigned int cmd, unsigned long arg)
854 int unit, err = -EFAULT;
856 struct channel *chan;
858 int __user *p = (int __user *)arg;
862 /* Create a new ppp unit */
863 if (get_user(unit, p))
865 err = ppp_create_interface(net, file, &unit);
870 if (put_user(unit, p))
876 /* Attach to an existing ppp unit */
877 if (get_user(unit, p))
880 pn = ppp_pernet(net);
881 mutex_lock(&pn->all_ppp_mutex);
882 ppp = ppp_find_unit(pn, unit);
884 atomic_inc(&ppp->file.refcnt);
885 file->private_data = &ppp->file;
888 mutex_unlock(&pn->all_ppp_mutex);
892 if (get_user(unit, p))
895 pn = ppp_pernet(net);
896 spin_lock_bh(&pn->all_channels_lock);
897 chan = ppp_find_channel(pn, unit);
899 atomic_inc(&chan->file.refcnt);
900 file->private_data = &chan->file;
903 spin_unlock_bh(&pn->all_channels_lock);
913 static const struct file_operations ppp_device_fops = {
914 .owner = THIS_MODULE,
918 .unlocked_ioctl = ppp_ioctl,
920 .release = ppp_release,
921 .llseek = noop_llseek,
924 static __net_init int ppp_init_net(struct net *net)
926 struct ppp_net *pn = net_generic(net, ppp_net_id);
928 idr_init(&pn->units_idr);
929 mutex_init(&pn->all_ppp_mutex);
931 INIT_LIST_HEAD(&pn->all_channels);
932 INIT_LIST_HEAD(&pn->new_channels);
934 spin_lock_init(&pn->all_channels_lock);
939 static __net_exit void ppp_exit_net(struct net *net)
941 struct ppp_net *pn = net_generic(net, ppp_net_id);
942 struct net_device *dev;
943 struct net_device *aux;
949 for_each_netdev_safe(net, dev, aux) {
950 if (dev->netdev_ops == &ppp_netdev_ops)
951 unregister_netdevice_queue(dev, &list);
954 idr_for_each_entry(&pn->units_idr, ppp, id)
955 /* Skip devices already unregistered by previous loop */
956 if (!net_eq(dev_net(ppp->dev), net))
957 unregister_netdevice_queue(ppp->dev, &list);
959 unregister_netdevice_many(&list);
962 idr_destroy(&pn->units_idr);
965 static struct pernet_operations ppp_net_ops = {
966 .init = ppp_init_net,
967 .exit = ppp_exit_net,
969 .size = sizeof(struct ppp_net),
972 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
974 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
977 mutex_lock(&pn->all_ppp_mutex);
980 ret = unit_get(&pn->units_idr, ppp);
984 /* Caller asked for a specific unit number. Fail with -EEXIST
985 * if unavailable. For backward compatibility, return -EEXIST
986 * too if idr allocation fails; this makes pppd retry without
987 * requesting a specific unit number.
989 if (unit_find(&pn->units_idr, unit)) {
993 ret = unit_set(&pn->units_idr, ppp, unit);
995 /* Rewrite error for backward compatibility */
1000 ppp->file.index = ret;
1003 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1005 ret = register_netdevice(ppp->dev);
1009 atomic_inc(&ppp_unit_count);
1011 mutex_unlock(&pn->all_ppp_mutex);
1016 unit_put(&pn->units_idr, ppp->file.index);
1018 mutex_unlock(&pn->all_ppp_mutex);
1023 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1024 const struct ppp_config *conf)
1026 struct ppp *ppp = netdev_priv(dev);
1032 ppp->ppp_net = src_net;
1034 ppp->owner = conf->file;
1036 init_ppp_file(&ppp->file, INTERFACE);
1037 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1039 for (indx = 0; indx < NUM_NP; ++indx)
1040 ppp->npmode[indx] = NPMODE_PASS;
1041 INIT_LIST_HEAD(&ppp->channels);
1042 spin_lock_init(&ppp->rlock);
1043 spin_lock_init(&ppp->wlock);
1045 ppp->xmit_recursion = alloc_percpu(int);
1046 if (!ppp->xmit_recursion) {
1050 for_each_possible_cpu(cpu)
1051 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1053 #ifdef CONFIG_PPP_MULTILINK
1055 skb_queue_head_init(&ppp->mrq);
1056 #endif /* CONFIG_PPP_MULTILINK */
1057 #ifdef CONFIG_PPP_FILTER
1058 ppp->pass_filter = NULL;
1059 ppp->active_filter = NULL;
1060 #endif /* CONFIG_PPP_FILTER */
1062 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1066 conf->file->private_data = &ppp->file;
1070 free_percpu(ppp->xmit_recursion);
1075 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1076 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1079 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1080 struct netlink_ext_ack *extack)
1085 if (!data[IFLA_PPP_DEV_FD])
1087 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1093 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1094 struct nlattr *tb[], struct nlattr *data[],
1095 struct netlink_ext_ack *extack)
1097 struct ppp_config conf = {
1099 .ifname_is_set = true,
1104 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1108 /* rtnl_lock is already held here, but ppp_create_interface() locks
1109 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1110 * possible deadlock due to lock order inversion, at the cost of
1111 * pushing the problem back to userspace.
1113 if (!mutex_trylock(&ppp_mutex)) {
1118 if (file->f_op != &ppp_device_fops || file->private_data) {
1125 /* Don't use device name generated by the rtnetlink layer when ifname
1126 * isn't specified. Let ppp_dev_configure() set the device name using
1127 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1128 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1130 if (!tb[IFLA_IFNAME])
1131 conf.ifname_is_set = false;
1133 err = ppp_dev_configure(src_net, dev, &conf);
1136 mutex_unlock(&ppp_mutex);
1143 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1145 unregister_netdevice_queue(dev, head);
1148 static size_t ppp_nl_get_size(const struct net_device *dev)
1153 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1158 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1160 struct ppp *ppp = netdev_priv(dev);
1162 return ppp->ppp_net;
1165 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1167 .maxtype = IFLA_PPP_MAX,
1168 .policy = ppp_nl_policy,
1169 .priv_size = sizeof(struct ppp),
1171 .validate = ppp_nl_validate,
1172 .newlink = ppp_nl_newlink,
1173 .dellink = ppp_nl_dellink,
1174 .get_size = ppp_nl_get_size,
1175 .fill_info = ppp_nl_fill_info,
1176 .get_link_net = ppp_nl_get_link_net,
1179 #define PPP_MAJOR 108
1181 /* Called at boot time if ppp is compiled into the kernel,
1182 or at module load time (from init_module) if compiled as a module. */
1183 static int __init ppp_init(void)
1187 pr_info("PPP generic driver version " PPP_VERSION "\n");
1189 err = register_pernet_device(&ppp_net_ops);
1191 pr_err("failed to register PPP pernet device (%d)\n", err);
1195 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1197 pr_err("failed to register PPP device (%d)\n", err);
1201 ppp_class = class_create(THIS_MODULE, "ppp");
1202 if (IS_ERR(ppp_class)) {
1203 err = PTR_ERR(ppp_class);
1207 err = rtnl_link_register(&ppp_link_ops);
1209 pr_err("failed to register rtnetlink PPP handler\n");
1213 /* not a big deal if we fail here :-) */
1214 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1219 class_destroy(ppp_class);
1221 unregister_chrdev(PPP_MAJOR, "ppp");
1223 unregister_pernet_device(&ppp_net_ops);
1229 * Network interface unit routines.
1232 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1234 struct ppp *ppp = netdev_priv(dev);
1238 npi = ethertype_to_npindex(ntohs(skb->protocol));
1242 /* Drop, accept or reject the packet */
1243 switch (ppp->npmode[npi]) {
1247 /* it would be nice to have a way to tell the network
1248 system to queue this one up for later. */
1255 /* Put the 2-byte PPP protocol number on the front,
1256 making sure there is room for the address and control fields. */
1257 if (skb_cow_head(skb, PPP_HDRLEN))
1260 pp = skb_push(skb, 2);
1261 proto = npindex_to_proto[npi];
1262 put_unaligned_be16(proto, pp);
1264 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1265 skb_queue_tail(&ppp->file.xq, skb);
1266 ppp_xmit_process(ppp);
1267 return NETDEV_TX_OK;
1271 ++dev->stats.tx_dropped;
1272 return NETDEV_TX_OK;
1276 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1278 struct ppp *ppp = netdev_priv(dev);
1280 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1281 struct ppp_stats stats;
1282 struct ppp_comp_stats cstats;
1287 ppp_get_stats(ppp, &stats);
1288 if (copy_to_user(addr, &stats, sizeof(stats)))
1293 case SIOCGPPPCSTATS:
1294 memset(&cstats, 0, sizeof(cstats));
1296 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1298 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1299 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1306 if (copy_to_user(addr, vers, strlen(vers) + 1))
1319 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1321 struct ppp *ppp = netdev_priv(dev);
1324 stats64->rx_packets = ppp->stats64.rx_packets;
1325 stats64->rx_bytes = ppp->stats64.rx_bytes;
1326 ppp_recv_unlock(ppp);
1329 stats64->tx_packets = ppp->stats64.tx_packets;
1330 stats64->tx_bytes = ppp->stats64.tx_bytes;
1331 ppp_xmit_unlock(ppp);
1333 stats64->rx_errors = dev->stats.rx_errors;
1334 stats64->tx_errors = dev->stats.tx_errors;
1335 stats64->rx_dropped = dev->stats.rx_dropped;
1336 stats64->tx_dropped = dev->stats.tx_dropped;
1337 stats64->rx_length_errors = dev->stats.rx_length_errors;
1340 static int ppp_dev_init(struct net_device *dev)
1344 netdev_lockdep_set_classes(dev);
1346 ppp = netdev_priv(dev);
1347 /* Let the netdevice take a reference on the ppp file. This ensures
1348 * that ppp_destroy_interface() won't run before the device gets
1351 atomic_inc(&ppp->file.refcnt);
1356 static void ppp_dev_uninit(struct net_device *dev)
1358 struct ppp *ppp = netdev_priv(dev);
1359 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1365 mutex_lock(&pn->all_ppp_mutex);
1366 unit_put(&pn->units_idr, ppp->file.index);
1367 mutex_unlock(&pn->all_ppp_mutex);
1372 wake_up_interruptible(&ppp->file.rwait);
1375 static void ppp_dev_priv_destructor(struct net_device *dev)
1379 ppp = netdev_priv(dev);
1380 if (atomic_dec_and_test(&ppp->file.refcnt))
1381 ppp_destroy_interface(ppp);
1384 static const struct net_device_ops ppp_netdev_ops = {
1385 .ndo_init = ppp_dev_init,
1386 .ndo_uninit = ppp_dev_uninit,
1387 .ndo_start_xmit = ppp_start_xmit,
1388 .ndo_do_ioctl = ppp_net_ioctl,
1389 .ndo_get_stats64 = ppp_get_stats64,
1392 static struct device_type ppp_type = {
1396 static void ppp_setup(struct net_device *dev)
1398 dev->netdev_ops = &ppp_netdev_ops;
1399 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1401 dev->features |= NETIF_F_LLTX;
1403 dev->hard_header_len = PPP_HDRLEN;
1406 dev->tx_queue_len = 3;
1407 dev->type = ARPHRD_PPP;
1408 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1409 dev->priv_destructor = ppp_dev_priv_destructor;
1410 netif_keep_dst(dev);
1414 * Transmit-side routines.
1417 /* Called to do any work queued up on the transmit side that can now be done */
1418 static void __ppp_xmit_process(struct ppp *ppp)
1420 struct sk_buff *skb;
1423 if (!ppp->closing) {
1425 while (!ppp->xmit_pending &&
1426 (skb = skb_dequeue(&ppp->file.xq)))
1427 ppp_send_frame(ppp, skb);
1428 /* If there's no work left to do, tell the core net
1429 code that we can accept some more. */
1430 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1431 netif_wake_queue(ppp->dev);
1433 netif_stop_queue(ppp->dev);
1435 ppp_xmit_unlock(ppp);
1438 static void ppp_xmit_process(struct ppp *ppp)
1442 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1445 (*this_cpu_ptr(ppp->xmit_recursion))++;
1446 __ppp_xmit_process(ppp);
1447 (*this_cpu_ptr(ppp->xmit_recursion))--;
1456 if (net_ratelimit())
1457 netdev_err(ppp->dev, "recursion detected\n");
1460 static inline struct sk_buff *
1461 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1463 struct sk_buff *new_skb;
1465 int new_skb_size = ppp->dev->mtu +
1466 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1467 int compressor_skb_size = ppp->dev->mtu +
1468 ppp->xcomp->comp_extra + PPP_HDRLEN;
1469 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1471 if (net_ratelimit())
1472 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1475 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1476 skb_reserve(new_skb,
1477 ppp->dev->hard_header_len - PPP_HDRLEN);
1479 /* compressor still expects A/C bytes in hdr */
1480 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1481 new_skb->data, skb->len + 2,
1482 compressor_skb_size);
1483 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1487 skb_pull(skb, 2); /* pull off A/C bytes */
1488 } else if (len == 0) {
1489 /* didn't compress, or CCP not up yet */
1490 consume_skb(new_skb);
1495 * MPPE requires that we do not send unencrypted
1496 * frames. The compressor will return -1 if we
1497 * should drop the frame. We cannot simply test
1498 * the compress_proto because MPPE and MPPC share
1501 if (net_ratelimit())
1502 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1504 consume_skb(new_skb);
1511 * Compress and send a frame.
1512 * The caller should have locked the xmit path,
1513 * and xmit_pending should be 0.
1516 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1518 int proto = PPP_PROTO(skb);
1519 struct sk_buff *new_skb;
1523 if (proto < 0x8000) {
1524 #ifdef CONFIG_PPP_FILTER
1525 /* check if we should pass this packet */
1526 /* the filter instructions are constructed assuming
1527 a four-byte PPP header on each packet */
1528 *(u8 *)skb_push(skb, 2) = 1;
1529 if (ppp->pass_filter &&
1530 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1532 netdev_printk(KERN_DEBUG, ppp->dev,
1533 "PPP: outbound frame "
1538 /* if this packet passes the active filter, record the time */
1539 if (!(ppp->active_filter &&
1540 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1541 ppp->last_xmit = jiffies;
1544 /* for data packets, record the time */
1545 ppp->last_xmit = jiffies;
1546 #endif /* CONFIG_PPP_FILTER */
1549 ++ppp->stats64.tx_packets;
1550 ppp->stats64.tx_bytes += skb->len - 2;
1554 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1556 /* try to do VJ TCP header compression */
1557 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1560 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1563 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1565 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1566 new_skb->data + 2, &cp,
1567 !(ppp->flags & SC_NO_TCP_CCID));
1568 if (cp == skb->data + 2) {
1569 /* didn't compress */
1570 consume_skb(new_skb);
1572 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1573 proto = PPP_VJC_COMP;
1574 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1576 proto = PPP_VJC_UNCOMP;
1577 cp[0] = skb->data[2];
1581 cp = skb_put(skb, len + 2);
1588 /* peek at outbound CCP frames */
1589 ppp_ccp_peek(ppp, skb, 0);
1593 /* try to do packet compression */
1594 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1595 proto != PPP_LCP && proto != PPP_CCP) {
1596 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1597 if (net_ratelimit())
1598 netdev_err(ppp->dev,
1599 "ppp: compression required but "
1600 "down - pkt dropped.\n");
1603 skb = pad_compress_skb(ppp, skb);
1609 * If we are waiting for traffic (demand dialling),
1610 * queue it up for pppd to receive.
1612 if (ppp->flags & SC_LOOP_TRAFFIC) {
1613 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1615 skb_queue_tail(&ppp->file.rq, skb);
1616 wake_up_interruptible(&ppp->file.rwait);
1620 ppp->xmit_pending = skb;
1626 ++ppp->dev->stats.tx_errors;
1630 * Try to send the frame in xmit_pending.
1631 * The caller should have the xmit path locked.
1634 ppp_push(struct ppp *ppp)
1636 struct list_head *list;
1637 struct channel *pch;
1638 struct sk_buff *skb = ppp->xmit_pending;
1643 list = &ppp->channels;
1644 if (list_empty(list)) {
1645 /* nowhere to send the packet, just drop it */
1646 ppp->xmit_pending = NULL;
1651 if ((ppp->flags & SC_MULTILINK) == 0) {
1652 /* not doing multilink: send it down the first channel */
1654 pch = list_entry(list, struct channel, clist);
1656 spin_lock(&pch->downl);
1658 if (pch->chan->ops->start_xmit(pch->chan, skb))
1659 ppp->xmit_pending = NULL;
1661 /* channel got unregistered */
1663 ppp->xmit_pending = NULL;
1665 spin_unlock(&pch->downl);
1669 #ifdef CONFIG_PPP_MULTILINK
1670 /* Multilink: fragment the packet over as many links
1671 as can take the packet at the moment. */
1672 if (!ppp_mp_explode(ppp, skb))
1674 #endif /* CONFIG_PPP_MULTILINK */
1676 ppp->xmit_pending = NULL;
1680 #ifdef CONFIG_PPP_MULTILINK
1681 static bool mp_protocol_compress __read_mostly = true;
1682 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1683 MODULE_PARM_DESC(mp_protocol_compress,
1684 "compress protocol id in multilink fragments");
1687 * Divide a packet to be transmitted into fragments and
1688 * send them out the individual links.
1690 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1693 int i, bits, hdrlen, mtu;
1695 int navail, nfree, nzero;
1699 unsigned char *p, *q;
1700 struct list_head *list;
1701 struct channel *pch;
1702 struct sk_buff *frag;
1703 struct ppp_channel *chan;
1705 totspeed = 0; /*total bitrate of the bundle*/
1706 nfree = 0; /* # channels which have no packet already queued */
1707 navail = 0; /* total # of usable channels (not deregistered) */
1708 nzero = 0; /* number of channels with zero speed associated*/
1709 totfree = 0; /*total # of channels available and
1710 *having no queued packets before
1711 *starting the fragmentation*/
1713 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1715 list_for_each_entry(pch, &ppp->channels, clist) {
1719 pch->speed = pch->chan->speed;
1724 if (skb_queue_empty(&pch->file.xq) ||
1726 if (pch->speed == 0)
1729 totspeed += pch->speed;
1735 if (!pch->had_frag && i < ppp->nxchan)
1741 * Don't start sending this packet unless at least half of
1742 * the channels are free. This gives much better TCP
1743 * performance if we have a lot of channels.
1745 if (nfree == 0 || nfree < navail / 2)
1746 return 0; /* can't take now, leave it in xmit_pending */
1748 /* Do protocol field compression */
1751 if (*p == 0 && mp_protocol_compress) {
1757 nbigger = len % nfree;
1759 /* skip to the channel after the one we last used
1760 and start at that one */
1761 list = &ppp->channels;
1762 for (i = 0; i < ppp->nxchan; ++i) {
1764 if (list == &ppp->channels) {
1770 /* create a fragment for each channel */
1774 if (list == &ppp->channels) {
1778 pch = list_entry(list, struct channel, clist);
1784 * Skip this channel if it has a fragment pending already and
1785 * we haven't given a fragment to all of the free channels.
1787 if (pch->avail == 1) {
1794 /* check the channel's mtu and whether it is still attached. */
1795 spin_lock(&pch->downl);
1796 if (pch->chan == NULL) {
1797 /* can't use this channel, it's being deregistered */
1798 if (pch->speed == 0)
1801 totspeed -= pch->speed;
1803 spin_unlock(&pch->downl);
1814 *if the channel speed is not set divide
1815 *the packet evenly among the free channels;
1816 *otherwise divide it according to the speed
1817 *of the channel we are going to transmit on
1821 if (pch->speed == 0) {
1828 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1829 ((totspeed*totfree)/pch->speed)) - hdrlen;
1831 flen += ((totfree - nzero)*pch->speed)/totspeed;
1832 nbigger -= ((totfree - nzero)*pch->speed)/
1840 *check if we are on the last channel or
1841 *we exceded the length of the data to
1844 if ((nfree <= 0) || (flen > len))
1847 *it is not worth to tx on slow channels:
1848 *in that case from the resulting flen according to the
1849 *above formula will be equal or less than zero.
1850 *Skip the channel in this case
1854 spin_unlock(&pch->downl);
1859 * hdrlen includes the 2-byte PPP protocol field, but the
1860 * MTU counts only the payload excluding the protocol field.
1861 * (RFC1661 Section 2)
1863 mtu = pch->chan->mtu - (hdrlen - 2);
1870 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1873 q = skb_put(frag, flen + hdrlen);
1875 /* make the MP header */
1876 put_unaligned_be16(PPP_MP, q);
1877 if (ppp->flags & SC_MP_XSHORTSEQ) {
1878 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1882 q[3] = ppp->nxseq >> 16;
1883 q[4] = ppp->nxseq >> 8;
1887 memcpy(q + hdrlen, p, flen);
1889 /* try to send it down the channel */
1891 if (!skb_queue_empty(&pch->file.xq) ||
1892 !chan->ops->start_xmit(chan, frag))
1893 skb_queue_tail(&pch->file.xq, frag);
1899 spin_unlock(&pch->downl);
1906 spin_unlock(&pch->downl);
1908 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1909 ++ppp->dev->stats.tx_errors;
1911 return 1; /* abandon the frame */
1913 #endif /* CONFIG_PPP_MULTILINK */
1915 /* Try to send data out on a channel */
1916 static void __ppp_channel_push(struct channel *pch)
1918 struct sk_buff *skb;
1921 spin_lock(&pch->downl);
1923 while (!skb_queue_empty(&pch->file.xq)) {
1924 skb = skb_dequeue(&pch->file.xq);
1925 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1926 /* put the packet back and try again later */
1927 skb_queue_head(&pch->file.xq, skb);
1932 /* channel got deregistered */
1933 skb_queue_purge(&pch->file.xq);
1935 spin_unlock(&pch->downl);
1936 /* see if there is anything from the attached unit to be sent */
1937 if (skb_queue_empty(&pch->file.xq)) {
1940 __ppp_xmit_process(ppp);
1944 static void ppp_channel_push(struct channel *pch)
1946 read_lock_bh(&pch->upl);
1948 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
1949 __ppp_channel_push(pch);
1950 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
1952 __ppp_channel_push(pch);
1954 read_unlock_bh(&pch->upl);
1958 * Receive-side routines.
1961 struct ppp_mp_skb_parm {
1965 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1968 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1972 ppp_receive_frame(ppp, skb, pch);
1975 ppp_recv_unlock(ppp);
1979 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1981 struct channel *pch = chan->ppp;
1989 read_lock_bh(&pch->upl);
1990 if (!pskb_may_pull(skb, 2)) {
1993 ++pch->ppp->dev->stats.rx_length_errors;
1994 ppp_receive_error(pch->ppp);
1999 proto = PPP_PROTO(skb);
2000 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2001 /* put it on the channel queue */
2002 skb_queue_tail(&pch->file.rq, skb);
2003 /* drop old frames if queue too long */
2004 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2005 (skb = skb_dequeue(&pch->file.rq)))
2007 wake_up_interruptible(&pch->file.rwait);
2009 ppp_do_recv(pch->ppp, skb, pch);
2013 read_unlock_bh(&pch->upl);
2016 /* Put a 0-length skb in the receive queue as an error indication */
2018 ppp_input_error(struct ppp_channel *chan, int code)
2020 struct channel *pch = chan->ppp;
2021 struct sk_buff *skb;
2026 read_lock_bh(&pch->upl);
2028 skb = alloc_skb(0, GFP_ATOMIC);
2030 skb->len = 0; /* probably unnecessary */
2032 ppp_do_recv(pch->ppp, skb, pch);
2035 read_unlock_bh(&pch->upl);
2039 * We come in here to process a received frame.
2040 * The receive side of the ppp unit is locked.
2043 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2045 /* note: a 0-length skb is used as an error indication */
2047 skb_checksum_complete_unset(skb);
2048 #ifdef CONFIG_PPP_MULTILINK
2049 /* XXX do channel-level decompression here */
2050 if (PPP_PROTO(skb) == PPP_MP)
2051 ppp_receive_mp_frame(ppp, skb, pch);
2053 #endif /* CONFIG_PPP_MULTILINK */
2054 ppp_receive_nonmp_frame(ppp, skb);
2057 ppp_receive_error(ppp);
2062 ppp_receive_error(struct ppp *ppp)
2064 ++ppp->dev->stats.rx_errors;
2070 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2073 int proto, len, npi;
2076 * Decompress the frame, if compressed.
2077 * Note that some decompressors need to see uncompressed frames
2078 * that come in as well as compressed frames.
2080 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2081 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2082 skb = ppp_decompress_frame(ppp, skb);
2084 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2087 proto = PPP_PROTO(skb);
2090 /* decompress VJ compressed packets */
2091 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2094 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2095 /* copy to a new sk_buff with more tailroom */
2096 ns = dev_alloc_skb(skb->len + 128);
2098 netdev_err(ppp->dev, "PPP: no memory "
2103 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2108 skb->ip_summed = CHECKSUM_NONE;
2110 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2112 netdev_printk(KERN_DEBUG, ppp->dev,
2113 "PPP: VJ decompression error\n");
2118 skb_put(skb, len - skb->len);
2119 else if (len < skb->len)
2124 case PPP_VJC_UNCOMP:
2125 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2128 /* Until we fix the decompressor need to make sure
2129 * data portion is linear.
2131 if (!pskb_may_pull(skb, skb->len))
2134 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2135 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2142 ppp_ccp_peek(ppp, skb, 1);
2146 ++ppp->stats64.rx_packets;
2147 ppp->stats64.rx_bytes += skb->len - 2;
2149 npi = proto_to_npindex(proto);
2151 /* control or unknown frame - pass it to pppd */
2152 skb_queue_tail(&ppp->file.rq, skb);
2153 /* limit queue length by dropping old frames */
2154 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2155 (skb = skb_dequeue(&ppp->file.rq)))
2157 /* wake up any process polling or blocking on read */
2158 wake_up_interruptible(&ppp->file.rwait);
2161 /* network protocol frame - give it to the kernel */
2163 #ifdef CONFIG_PPP_FILTER
2164 /* check if the packet passes the pass and active filters */
2165 /* the filter instructions are constructed assuming
2166 a four-byte PPP header on each packet */
2167 if (ppp->pass_filter || ppp->active_filter) {
2168 if (skb_unclone(skb, GFP_ATOMIC))
2171 *(u8 *)skb_push(skb, 2) = 0;
2172 if (ppp->pass_filter &&
2173 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2175 netdev_printk(KERN_DEBUG, ppp->dev,
2176 "PPP: inbound frame "
2181 if (!(ppp->active_filter &&
2182 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2183 ppp->last_recv = jiffies;
2186 #endif /* CONFIG_PPP_FILTER */
2187 ppp->last_recv = jiffies;
2189 if ((ppp->dev->flags & IFF_UP) == 0 ||
2190 ppp->npmode[npi] != NPMODE_PASS) {
2193 /* chop off protocol */
2194 skb_pull_rcsum(skb, 2);
2195 skb->dev = ppp->dev;
2196 skb->protocol = htons(npindex_to_ethertype[npi]);
2197 skb_reset_mac_header(skb);
2198 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2199 dev_net(ppp->dev)));
2207 ppp_receive_error(ppp);
2210 static struct sk_buff *
2211 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2213 int proto = PPP_PROTO(skb);
2217 /* Until we fix all the decompressor's need to make sure
2218 * data portion is linear.
2220 if (!pskb_may_pull(skb, skb->len))
2223 if (proto == PPP_COMP) {
2226 switch(ppp->rcomp->compress_proto) {
2228 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2231 obuff_size = ppp->mru + PPP_HDRLEN;
2235 ns = dev_alloc_skb(obuff_size);
2237 netdev_err(ppp->dev, "ppp_decompress_frame: "
2241 /* the decompressor still expects the A/C bytes in the hdr */
2242 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2243 skb->len + 2, ns->data, obuff_size);
2245 /* Pass the compressed frame to pppd as an
2246 error indication. */
2247 if (len == DECOMP_FATALERROR)
2248 ppp->rstate |= SC_DC_FERROR;
2256 skb_pull(skb, 2); /* pull off the A/C bytes */
2259 /* Uncompressed frame - pass to decompressor so it
2260 can update its dictionary if necessary. */
2261 if (ppp->rcomp->incomp)
2262 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2269 ppp->rstate |= SC_DC_ERROR;
2270 ppp_receive_error(ppp);
2274 #ifdef CONFIG_PPP_MULTILINK
2276 * Receive a multilink frame.
2277 * We put it on the reconstruction queue and then pull off
2278 * as many completed frames as we can.
2281 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2285 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2287 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2288 goto err; /* no good, throw it away */
2290 /* Decode sequence number and begin/end bits */
2291 if (ppp->flags & SC_MP_SHORTSEQ) {
2292 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2295 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2298 PPP_MP_CB(skb)->BEbits = skb->data[2];
2299 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2302 * Do protocol ID decompression on the first fragment of each packet.
2304 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2305 *(u8 *)skb_push(skb, 1) = 0;
2308 * Expand sequence number to 32 bits, making it as close
2309 * as possible to ppp->minseq.
2311 seq |= ppp->minseq & ~mask;
2312 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2314 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2315 seq -= mask + 1; /* should never happen */
2316 PPP_MP_CB(skb)->sequence = seq;
2320 * If this packet comes before the next one we were expecting,
2323 if (seq_before(seq, ppp->nextseq)) {
2325 ++ppp->dev->stats.rx_dropped;
2326 ppp_receive_error(ppp);
2331 * Reevaluate minseq, the minimum over all channels of the
2332 * last sequence number received on each channel. Because of
2333 * the increasing sequence number rule, we know that any fragment
2334 * before `minseq' which hasn't arrived is never going to arrive.
2335 * The list of channels can't change because we have the receive
2336 * side of the ppp unit locked.
2338 list_for_each_entry(ch, &ppp->channels, clist) {
2339 if (seq_before(ch->lastseq, seq))
2342 if (seq_before(ppp->minseq, seq))
2345 /* Put the fragment on the reconstruction queue */
2346 ppp_mp_insert(ppp, skb);
2348 /* If the queue is getting long, don't wait any longer for packets
2349 before the start of the queue. */
2350 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2351 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2352 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2353 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2356 /* Pull completed packets off the queue and receive them. */
2357 while ((skb = ppp_mp_reconstruct(ppp))) {
2358 if (pskb_may_pull(skb, 2))
2359 ppp_receive_nonmp_frame(ppp, skb);
2361 ++ppp->dev->stats.rx_length_errors;
2363 ppp_receive_error(ppp);
2371 ppp_receive_error(ppp);
2375 * Insert a fragment on the MP reconstruction queue.
2376 * The queue is ordered by increasing sequence number.
2379 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2382 struct sk_buff_head *list = &ppp->mrq;
2383 u32 seq = PPP_MP_CB(skb)->sequence;
2385 /* N.B. we don't need to lock the list lock because we have the
2386 ppp unit receive-side lock. */
2387 skb_queue_walk(list, p) {
2388 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2391 __skb_queue_before(list, p, skb);
2395 * Reconstruct a packet from the MP fragment queue.
2396 * We go through increasing sequence numbers until we find a
2397 * complete packet, or we get to the sequence number for a fragment
2398 * which hasn't arrived but might still do so.
2400 static struct sk_buff *
2401 ppp_mp_reconstruct(struct ppp *ppp)
2403 u32 seq = ppp->nextseq;
2404 u32 minseq = ppp->minseq;
2405 struct sk_buff_head *list = &ppp->mrq;
2406 struct sk_buff *p, *tmp;
2407 struct sk_buff *head, *tail;
2408 struct sk_buff *skb = NULL;
2409 int lost = 0, len = 0;
2411 if (ppp->mrru == 0) /* do nothing until mrru is set */
2415 skb_queue_walk_safe(list, p, tmp) {
2417 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2418 /* this can't happen, anyway ignore the skb */
2419 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2421 PPP_MP_CB(p)->sequence, seq);
2422 __skb_unlink(p, list);
2426 if (PPP_MP_CB(p)->sequence != seq) {
2428 /* Fragment `seq' is missing. If it is after
2429 minseq, it might arrive later, so stop here. */
2430 if (seq_after(seq, minseq))
2432 /* Fragment `seq' is lost, keep going. */
2435 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2436 minseq + 1: PPP_MP_CB(p)->sequence;
2439 netdev_printk(KERN_DEBUG, ppp->dev,
2440 "lost frag %u..%u\n",
2447 * At this point we know that all the fragments from
2448 * ppp->nextseq to seq are either present or lost.
2449 * Also, there are no complete packets in the queue
2450 * that have no missing fragments and end before this
2454 /* B bit set indicates this fragment starts a packet */
2455 if (PPP_MP_CB(p)->BEbits & B) {
2463 /* Got a complete packet yet? */
2464 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2465 (PPP_MP_CB(head)->BEbits & B)) {
2466 if (len > ppp->mrru + 2) {
2467 ++ppp->dev->stats.rx_length_errors;
2468 netdev_printk(KERN_DEBUG, ppp->dev,
2469 "PPP: reconstructed packet"
2470 " is too long (%d)\n", len);
2475 ppp->nextseq = seq + 1;
2479 * If this is the ending fragment of a packet,
2480 * and we haven't found a complete valid packet yet,
2481 * we can discard up to and including this fragment.
2483 if (PPP_MP_CB(p)->BEbits & E) {
2484 struct sk_buff *tmp2;
2486 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2488 netdev_printk(KERN_DEBUG, ppp->dev,
2489 "discarding frag %u\n",
2490 PPP_MP_CB(p)->sequence);
2491 __skb_unlink(p, list);
2494 head = skb_peek(list);
2501 /* If we have a complete packet, copy it all into one skb. */
2503 /* If we have discarded any fragments,
2504 signal a receive error. */
2505 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2506 skb_queue_walk_safe(list, p, tmp) {
2510 netdev_printk(KERN_DEBUG, ppp->dev,
2511 "discarding frag %u\n",
2512 PPP_MP_CB(p)->sequence);
2513 __skb_unlink(p, list);
2518 netdev_printk(KERN_DEBUG, ppp->dev,
2519 " missed pkts %u..%u\n",
2521 PPP_MP_CB(head)->sequence-1);
2522 ++ppp->dev->stats.rx_dropped;
2523 ppp_receive_error(ppp);
2528 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2529 p = skb_queue_next(list, head);
2530 __skb_unlink(skb, list);
2531 skb_queue_walk_from_safe(list, p, tmp) {
2532 __skb_unlink(p, list);
2538 skb->data_len += p->len;
2539 skb->truesize += p->truesize;
2545 __skb_unlink(skb, list);
2548 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2553 #endif /* CONFIG_PPP_MULTILINK */
2556 * Channel interface.
2559 /* Create a new, unattached ppp channel. */
2560 int ppp_register_channel(struct ppp_channel *chan)
2562 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2565 /* Create a new, unattached ppp channel for specified net. */
2566 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2568 struct channel *pch;
2571 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2575 pn = ppp_pernet(net);
2579 pch->chan_net = get_net(net);
2581 init_ppp_file(&pch->file, CHANNEL);
2582 pch->file.hdrlen = chan->hdrlen;
2583 #ifdef CONFIG_PPP_MULTILINK
2585 #endif /* CONFIG_PPP_MULTILINK */
2586 init_rwsem(&pch->chan_sem);
2587 spin_lock_init(&pch->downl);
2588 rwlock_init(&pch->upl);
2590 spin_lock_bh(&pn->all_channels_lock);
2591 pch->file.index = ++pn->last_channel_index;
2592 list_add(&pch->list, &pn->new_channels);
2593 atomic_inc(&channel_count);
2594 spin_unlock_bh(&pn->all_channels_lock);
2600 * Return the index of a channel.
2602 int ppp_channel_index(struct ppp_channel *chan)
2604 struct channel *pch = chan->ppp;
2607 return pch->file.index;
2612 * Return the PPP unit number to which a channel is connected.
2614 int ppp_unit_number(struct ppp_channel *chan)
2616 struct channel *pch = chan->ppp;
2620 read_lock_bh(&pch->upl);
2622 unit = pch->ppp->file.index;
2623 read_unlock_bh(&pch->upl);
2629 * Return the PPP device interface name of a channel.
2631 char *ppp_dev_name(struct ppp_channel *chan)
2633 struct channel *pch = chan->ppp;
2637 read_lock_bh(&pch->upl);
2638 if (pch->ppp && pch->ppp->dev)
2639 name = pch->ppp->dev->name;
2640 read_unlock_bh(&pch->upl);
2647 * Disconnect a channel from the generic layer.
2648 * This must be called in process context.
2651 ppp_unregister_channel(struct ppp_channel *chan)
2653 struct channel *pch = chan->ppp;
2657 return; /* should never happen */
2662 * This ensures that we have returned from any calls into the
2663 * the channel's start_xmit or ioctl routine before we proceed.
2665 down_write(&pch->chan_sem);
2666 spin_lock_bh(&pch->downl);
2668 spin_unlock_bh(&pch->downl);
2669 up_write(&pch->chan_sem);
2670 ppp_disconnect_channel(pch);
2672 pn = ppp_pernet(pch->chan_net);
2673 spin_lock_bh(&pn->all_channels_lock);
2674 list_del(&pch->list);
2675 spin_unlock_bh(&pn->all_channels_lock);
2678 wake_up_interruptible(&pch->file.rwait);
2679 if (atomic_dec_and_test(&pch->file.refcnt))
2680 ppp_destroy_channel(pch);
2684 * Callback from a channel when it can accept more to transmit.
2685 * This should be called at BH/softirq level, not interrupt level.
2688 ppp_output_wakeup(struct ppp_channel *chan)
2690 struct channel *pch = chan->ppp;
2694 ppp_channel_push(pch);
2698 * Compression control.
2701 /* Process the PPPIOCSCOMPRESS ioctl. */
2703 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2706 struct compressor *cp, *ocomp;
2707 struct ppp_option_data data;
2708 void *state, *ostate;
2709 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2712 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2714 if (data.length > CCP_MAX_OPTION_LENGTH)
2716 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2720 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2723 cp = try_then_request_module(
2724 find_compressor(ccp_option[0]),
2725 "ppp-compress-%d", ccp_option[0]);
2730 if (data.transmit) {
2731 state = cp->comp_alloc(ccp_option, data.length);
2734 ppp->xstate &= ~SC_COMP_RUN;
2736 ostate = ppp->xc_state;
2738 ppp->xc_state = state;
2739 ppp_xmit_unlock(ppp);
2741 ocomp->comp_free(ostate);
2742 module_put(ocomp->owner);
2746 module_put(cp->owner);
2749 state = cp->decomp_alloc(ccp_option, data.length);
2752 ppp->rstate &= ~SC_DECOMP_RUN;
2754 ostate = ppp->rc_state;
2756 ppp->rc_state = state;
2757 ppp_recv_unlock(ppp);
2759 ocomp->decomp_free(ostate);
2760 module_put(ocomp->owner);
2764 module_put(cp->owner);
2772 * Look at a CCP packet and update our state accordingly.
2773 * We assume the caller has the xmit or recv path locked.
2776 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2781 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2782 return; /* no header */
2785 switch (CCP_CODE(dp)) {
2788 /* A ConfReq starts negotiation of compression
2789 * in one direction of transmission,
2790 * and hence brings it down...but which way?
2793 * A ConfReq indicates what the sender would like to receive
2796 /* He is proposing what I should send */
2797 ppp->xstate &= ~SC_COMP_RUN;
2799 /* I am proposing to what he should send */
2800 ppp->rstate &= ~SC_DECOMP_RUN;
2807 * CCP is going down, both directions of transmission
2809 ppp->rstate &= ~SC_DECOMP_RUN;
2810 ppp->xstate &= ~SC_COMP_RUN;
2814 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2816 len = CCP_LENGTH(dp);
2817 if (!pskb_may_pull(skb, len + 2))
2818 return; /* too short */
2821 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2824 /* we will start receiving compressed packets */
2827 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2828 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2829 ppp->rstate |= SC_DECOMP_RUN;
2830 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2833 /* we will soon start sending compressed packets */
2836 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2837 ppp->file.index, 0, ppp->debug))
2838 ppp->xstate |= SC_COMP_RUN;
2843 /* reset the [de]compressor */
2844 if ((ppp->flags & SC_CCP_UP) == 0)
2847 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2848 ppp->rcomp->decomp_reset(ppp->rc_state);
2849 ppp->rstate &= ~SC_DC_ERROR;
2852 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2853 ppp->xcomp->comp_reset(ppp->xc_state);
2859 /* Free up compression resources. */
2861 ppp_ccp_closed(struct ppp *ppp)
2863 void *xstate, *rstate;
2864 struct compressor *xcomp, *rcomp;
2867 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2870 xstate = ppp->xc_state;
2871 ppp->xc_state = NULL;
2874 rstate = ppp->rc_state;
2875 ppp->rc_state = NULL;
2879 xcomp->comp_free(xstate);
2880 module_put(xcomp->owner);
2883 rcomp->decomp_free(rstate);
2884 module_put(rcomp->owner);
2888 /* List of compressors. */
2889 static LIST_HEAD(compressor_list);
2890 static DEFINE_SPINLOCK(compressor_list_lock);
2892 struct compressor_entry {
2893 struct list_head list;
2894 struct compressor *comp;
2897 static struct compressor_entry *
2898 find_comp_entry(int proto)
2900 struct compressor_entry *ce;
2902 list_for_each_entry(ce, &compressor_list, list) {
2903 if (ce->comp->compress_proto == proto)
2909 /* Register a compressor */
2911 ppp_register_compressor(struct compressor *cp)
2913 struct compressor_entry *ce;
2915 spin_lock(&compressor_list_lock);
2917 if (find_comp_entry(cp->compress_proto))
2920 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2925 list_add(&ce->list, &compressor_list);
2927 spin_unlock(&compressor_list_lock);
2931 /* Unregister a compressor */
2933 ppp_unregister_compressor(struct compressor *cp)
2935 struct compressor_entry *ce;
2937 spin_lock(&compressor_list_lock);
2938 ce = find_comp_entry(cp->compress_proto);
2939 if (ce && ce->comp == cp) {
2940 list_del(&ce->list);
2943 spin_unlock(&compressor_list_lock);
2946 /* Find a compressor. */
2947 static struct compressor *
2948 find_compressor(int type)
2950 struct compressor_entry *ce;
2951 struct compressor *cp = NULL;
2953 spin_lock(&compressor_list_lock);
2954 ce = find_comp_entry(type);
2957 if (!try_module_get(cp->owner))
2960 spin_unlock(&compressor_list_lock);
2965 * Miscelleneous stuff.
2969 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2971 struct slcompress *vj = ppp->vj;
2973 memset(st, 0, sizeof(*st));
2974 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2975 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2976 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2977 st->p.ppp_opackets = ppp->stats64.tx_packets;
2978 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2979 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2982 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2983 st->vj.vjs_compressed = vj->sls_o_compressed;
2984 st->vj.vjs_searches = vj->sls_o_searches;
2985 st->vj.vjs_misses = vj->sls_o_misses;
2986 st->vj.vjs_errorin = vj->sls_i_error;
2987 st->vj.vjs_tossed = vj->sls_i_tossed;
2988 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2989 st->vj.vjs_compressedin = vj->sls_i_compressed;
2993 * Stuff for handling the lists of ppp units and channels
2994 * and for initialization.
2998 * Create a new ppp interface unit. Fails if it can't allocate memory
2999 * or if there is already a unit with the requested number.
3000 * unit == -1 means allocate a new number.
3002 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3004 struct ppp_config conf = {
3007 .ifname_is_set = false,
3009 struct net_device *dev;
3013 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3018 dev_net_set(dev, net);
3019 dev->rtnl_link_ops = &ppp_link_ops;
3023 err = ppp_dev_configure(net, dev, &conf);
3026 ppp = netdev_priv(dev);
3027 *unit = ppp->file.index;
3041 * Initialize a ppp_file structure.
3044 init_ppp_file(struct ppp_file *pf, int kind)
3047 skb_queue_head_init(&pf->xq);
3048 skb_queue_head_init(&pf->rq);
3049 atomic_set(&pf->refcnt, 1);
3050 init_waitqueue_head(&pf->rwait);
3054 * Free the memory used by a ppp unit. This is only called once
3055 * there are no channels connected to the unit and no file structs
3056 * that reference the unit.
3058 static void ppp_destroy_interface(struct ppp *ppp)
3060 atomic_dec(&ppp_unit_count);
3062 if (!ppp->file.dead || ppp->n_channels) {
3063 /* "can't happen" */
3064 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3065 "but dead=%d n_channels=%d !\n",
3066 ppp, ppp->file.dead, ppp->n_channels);
3070 ppp_ccp_closed(ppp);
3075 skb_queue_purge(&ppp->file.xq);
3076 skb_queue_purge(&ppp->file.rq);
3077 #ifdef CONFIG_PPP_MULTILINK
3078 skb_queue_purge(&ppp->mrq);
3079 #endif /* CONFIG_PPP_MULTILINK */
3080 #ifdef CONFIG_PPP_FILTER
3081 if (ppp->pass_filter) {
3082 bpf_prog_destroy(ppp->pass_filter);
3083 ppp->pass_filter = NULL;
3086 if (ppp->active_filter) {
3087 bpf_prog_destroy(ppp->active_filter);
3088 ppp->active_filter = NULL;
3090 #endif /* CONFIG_PPP_FILTER */
3092 kfree_skb(ppp->xmit_pending);
3093 free_percpu(ppp->xmit_recursion);
3095 free_netdev(ppp->dev);
3099 * Locate an existing ppp unit.
3100 * The caller should have locked the all_ppp_mutex.
3103 ppp_find_unit(struct ppp_net *pn, int unit)
3105 return unit_find(&pn->units_idr, unit);
3109 * Locate an existing ppp channel.
3110 * The caller should have locked the all_channels_lock.
3111 * First we look in the new_channels list, then in the
3112 * all_channels list. If found in the new_channels list,
3113 * we move it to the all_channels list. This is for speed
3114 * when we have a lot of channels in use.
3116 static struct channel *
3117 ppp_find_channel(struct ppp_net *pn, int unit)
3119 struct channel *pch;
3121 list_for_each_entry(pch, &pn->new_channels, list) {
3122 if (pch->file.index == unit) {
3123 list_move(&pch->list, &pn->all_channels);
3128 list_for_each_entry(pch, &pn->all_channels, list) {
3129 if (pch->file.index == unit)
3137 * Connect a PPP channel to a PPP interface unit.
3140 ppp_connect_channel(struct channel *pch, int unit)
3147 pn = ppp_pernet(pch->chan_net);
3149 mutex_lock(&pn->all_ppp_mutex);
3150 ppp = ppp_find_unit(pn, unit);
3153 write_lock_bh(&pch->upl);
3159 if (pch->file.hdrlen > ppp->file.hdrlen)
3160 ppp->file.hdrlen = pch->file.hdrlen;
3161 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3162 if (hdrlen > ppp->dev->hard_header_len)
3163 ppp->dev->hard_header_len = hdrlen;
3164 list_add_tail(&pch->clist, &ppp->channels);
3167 atomic_inc(&ppp->file.refcnt);
3172 write_unlock_bh(&pch->upl);
3174 mutex_unlock(&pn->all_ppp_mutex);
3179 * Disconnect a channel from its ppp unit.
3182 ppp_disconnect_channel(struct channel *pch)
3187 write_lock_bh(&pch->upl);
3190 write_unlock_bh(&pch->upl);
3192 /* remove it from the ppp unit's list */
3194 list_del(&pch->clist);
3195 if (--ppp->n_channels == 0)
3196 wake_up_interruptible(&ppp->file.rwait);
3198 if (atomic_dec_and_test(&ppp->file.refcnt))
3199 ppp_destroy_interface(ppp);
3206 * Free up the resources used by a ppp channel.
3208 static void ppp_destroy_channel(struct channel *pch)
3210 put_net(pch->chan_net);
3211 pch->chan_net = NULL;
3213 atomic_dec(&channel_count);
3215 if (!pch->file.dead) {
3216 /* "can't happen" */
3217 pr_err("ppp: destroying undead channel %p !\n", pch);
3220 skb_queue_purge(&pch->file.xq);
3221 skb_queue_purge(&pch->file.rq);
3225 static void __exit ppp_cleanup(void)
3227 /* should never happen */
3228 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3229 pr_err("PPP: removing module but units remain!\n");
3230 rtnl_link_unregister(&ppp_link_ops);
3231 unregister_chrdev(PPP_MAJOR, "ppp");
3232 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3233 class_destroy(ppp_class);
3234 unregister_pernet_device(&ppp_net_ops);
3238 * Units handling. Caller must protect concurrent access
3239 * by holding all_ppp_mutex
3242 /* associate pointer with specified number */
3243 static int unit_set(struct idr *p, void *ptr, int n)
3247 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3248 if (unit == -ENOSPC)
3253 /* get new free unit number and associate pointer with it */
3254 static int unit_get(struct idr *p, void *ptr)
3256 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3259 /* put unit number back to a pool */
3260 static void unit_put(struct idr *p, int n)
3265 /* get pointer associated with the number */
3266 static void *unit_find(struct idr *p, int n)
3268 return idr_find(p, n);
3271 /* Module/initialization stuff */
3273 module_init(ppp_init);
3274 module_exit(ppp_cleanup);
3276 EXPORT_SYMBOL(ppp_register_net_channel);
3277 EXPORT_SYMBOL(ppp_register_channel);
3278 EXPORT_SYMBOL(ppp_unregister_channel);
3279 EXPORT_SYMBOL(ppp_channel_index);
3280 EXPORT_SYMBOL(ppp_unit_number);
3281 EXPORT_SYMBOL(ppp_dev_name);
3282 EXPORT_SYMBOL(ppp_input);
3283 EXPORT_SYMBOL(ppp_input_error);
3284 EXPORT_SYMBOL(ppp_output_wakeup);
3285 EXPORT_SYMBOL(ppp_register_compressor);
3286 EXPORT_SYMBOL(ppp_unregister_compressor);
3287 MODULE_LICENSE("GPL");
3288 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3289 MODULE_ALIAS_RTNL_LINK("ppp");
3290 MODULE_ALIAS("devname:ppp");