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 mru; /* max receive unit 60 */
124 unsigned int flags; /* control bits 64 */
125 unsigned int xstate; /* transmit state bits 68 */
126 unsigned int rstate; /* receive state bits 6c */
127 int debug; /* debug flags 70 */
128 struct slcompress *vj; /* state for VJ header compression */
129 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
130 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
131 struct compressor *xcomp; /* transmit packet compressor 8c */
132 void *xc_state; /* its internal state 90 */
133 struct compressor *rcomp; /* receive decompressor 94 */
134 void *rc_state; /* its internal state 98 */
135 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
136 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
137 struct net_device *dev; /* network interface device a4 */
138 int closing; /* is device closing down? a8 */
139 #ifdef CONFIG_PPP_MULTILINK
140 int nxchan; /* next channel to send something on */
141 u32 nxseq; /* next sequence number to send */
142 int mrru; /* MP: max reconst. receive unit */
143 u32 nextseq; /* MP: seq no of next packet */
144 u32 minseq; /* MP: min of most recent seqnos */
145 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
146 #endif /* CONFIG_PPP_MULTILINK */
147 #ifdef CONFIG_PPP_FILTER
148 struct bpf_prog *pass_filter; /* filter for packets to pass */
149 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
150 #endif /* CONFIG_PPP_FILTER */
151 struct net *ppp_net; /* the net we belong to */
152 struct ppp_link_stats stats64; /* 64 bit network stats */
156 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
157 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
159 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
160 * Bits in xstate: SC_COMP_RUN
162 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
163 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
164 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
167 * Private data structure for each channel.
168 * This includes the data structure used for multilink.
171 struct ppp_file file; /* stuff for read/write/poll */
172 struct list_head list; /* link in all/new_channels list */
173 struct ppp_channel *chan; /* public channel data structure */
174 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
175 spinlock_t downl; /* protects `chan', file.xq dequeue */
176 struct ppp *ppp; /* ppp unit we're connected to */
177 struct net *chan_net; /* the net channel belongs to */
178 struct list_head clist; /* link in list of channels per unit */
179 rwlock_t upl; /* protects `ppp' */
180 #ifdef CONFIG_PPP_MULTILINK
181 u8 avail; /* flag used in multilink stuff */
182 u8 had_frag; /* >= 1 fragments have been sent */
183 u32 lastseq; /* MP: last sequence # received */
184 int speed; /* speed of the corresponding ppp channel*/
185 #endif /* CONFIG_PPP_MULTILINK */
195 * SMP locking issues:
196 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
197 * list and the ppp.n_channels field, you need to take both locks
198 * before you modify them.
199 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
203 static DEFINE_MUTEX(ppp_mutex);
204 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
205 static atomic_t channel_count = ATOMIC_INIT(0);
207 /* per-net private data for this module */
208 static unsigned int ppp_net_id __read_mostly;
210 /* units to ppp mapping */
211 struct idr units_idr;
214 * all_ppp_mutex protects the units_idr mapping.
215 * It also ensures that finding a ppp unit in the units_idr
216 * map and updating its file.refcnt field is atomic.
218 struct mutex all_ppp_mutex;
221 struct list_head all_channels;
222 struct list_head new_channels;
223 int last_channel_index;
226 * all_channels_lock protects all_channels and
227 * last_channel_index, and the atomicity of find
228 * a channel and updating its file.refcnt field.
230 spinlock_t all_channels_lock;
233 /* Get the PPP protocol number from a skb */
234 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
236 /* We limit the length of ppp->file.rq to this (arbitrary) value */
237 #define PPP_MAX_RQLEN 32
240 * Maximum number of multilink fragments queued up.
241 * This has to be large enough to cope with the maximum latency of
242 * the slowest channel relative to the others. Strictly it should
243 * depend on the number of channels and their characteristics.
245 #define PPP_MP_MAX_QLEN 128
247 /* Multilink header bits. */
248 #define B 0x80 /* this fragment begins a packet */
249 #define E 0x40 /* this fragment ends a packet */
251 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
252 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
253 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
256 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
257 struct file *file, unsigned int cmd, unsigned long arg);
258 static void ppp_xmit_process(struct ppp *ppp);
259 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
260 static void ppp_push(struct ppp *ppp);
261 static void ppp_channel_push(struct channel *pch);
262 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
263 struct channel *pch);
264 static void ppp_receive_error(struct ppp *ppp);
265 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
266 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
267 struct sk_buff *skb);
268 #ifdef CONFIG_PPP_MULTILINK
269 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
270 struct channel *pch);
271 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
272 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
273 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
274 #endif /* CONFIG_PPP_MULTILINK */
275 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
276 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
277 static void ppp_ccp_closed(struct ppp *ppp);
278 static struct compressor *find_compressor(int type);
279 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
280 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
281 static void init_ppp_file(struct ppp_file *pf, int kind);
282 static void ppp_destroy_interface(struct ppp *ppp);
283 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
284 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
285 static int ppp_connect_channel(struct channel *pch, int unit);
286 static int ppp_disconnect_channel(struct channel *pch);
287 static void ppp_destroy_channel(struct channel *pch);
288 static int unit_get(struct idr *p, void *ptr);
289 static int unit_set(struct idr *p, void *ptr, int n);
290 static void unit_put(struct idr *p, int n);
291 static void *unit_find(struct idr *p, int n);
292 static void ppp_setup(struct net_device *dev);
294 static const struct net_device_ops ppp_netdev_ops;
296 static struct class *ppp_class;
298 /* per net-namespace data */
299 static inline struct ppp_net *ppp_pernet(struct net *net)
303 return net_generic(net, ppp_net_id);
306 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
307 static inline int proto_to_npindex(int proto)
326 /* Translates an NP index into a PPP protocol number */
327 static const int npindex_to_proto[NUM_NP] = {
336 /* Translates an ethertype into an NP index */
337 static inline int ethertype_to_npindex(int ethertype)
357 /* Translates an NP index into an ethertype */
358 static const int npindex_to_ethertype[NUM_NP] = {
370 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
371 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
372 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
373 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
374 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
375 ppp_recv_lock(ppp); } while (0)
376 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
377 ppp_xmit_unlock(ppp); } while (0)
380 * /dev/ppp device routines.
381 * The /dev/ppp device is used by pppd to control the ppp unit.
382 * It supports the read, write, ioctl and poll functions.
383 * Open instances of /dev/ppp can be in one of three states:
384 * unattached, attached to a ppp unit, or attached to a ppp channel.
386 static int ppp_open(struct inode *inode, struct file *file)
389 * This could (should?) be enforced by the permissions on /dev/ppp.
391 if (!capable(CAP_NET_ADMIN))
396 static int ppp_release(struct inode *unused, struct file *file)
398 struct ppp_file *pf = file->private_data;
402 file->private_data = NULL;
403 if (pf->kind == INTERFACE) {
406 if (file == ppp->owner)
407 unregister_netdevice(ppp->dev);
410 if (atomic_dec_and_test(&pf->refcnt)) {
413 ppp_destroy_interface(PF_TO_PPP(pf));
416 ppp_destroy_channel(PF_TO_CHANNEL(pf));
424 static ssize_t ppp_read(struct file *file, char __user *buf,
425 size_t count, loff_t *ppos)
427 struct ppp_file *pf = file->private_data;
428 DECLARE_WAITQUEUE(wait, current);
430 struct sk_buff *skb = NULL;
438 add_wait_queue(&pf->rwait, &wait);
440 set_current_state(TASK_INTERRUPTIBLE);
441 skb = skb_dequeue(&pf->rq);
447 if (pf->kind == INTERFACE) {
449 * Return 0 (EOF) on an interface that has no
450 * channels connected, unless it is looping
451 * network traffic (demand mode).
453 struct ppp *ppp = PF_TO_PPP(pf);
456 if (ppp->n_channels == 0 &&
457 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
458 ppp_recv_unlock(ppp);
461 ppp_recv_unlock(ppp);
464 if (file->f_flags & O_NONBLOCK)
467 if (signal_pending(current))
471 set_current_state(TASK_RUNNING);
472 remove_wait_queue(&pf->rwait, &wait);
478 if (skb->len > count)
483 iov_iter_init(&to, READ, &iov, 1, count);
484 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
494 static ssize_t ppp_write(struct file *file, const char __user *buf,
495 size_t count, loff_t *ppos)
497 struct ppp_file *pf = file->private_data;
504 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
507 skb_reserve(skb, pf->hdrlen);
509 if (copy_from_user(skb_put(skb, count), buf, count)) {
514 skb_queue_tail(&pf->xq, skb);
518 ppp_xmit_process(PF_TO_PPP(pf));
521 ppp_channel_push(PF_TO_CHANNEL(pf));
531 /* No kernel lock - fine */
532 static unsigned int ppp_poll(struct file *file, poll_table *wait)
534 struct ppp_file *pf = file->private_data;
539 poll_wait(file, &pf->rwait, wait);
540 mask = POLLOUT | POLLWRNORM;
541 if (skb_peek(&pf->rq))
542 mask |= POLLIN | POLLRDNORM;
545 else if (pf->kind == INTERFACE) {
546 /* see comment in ppp_read */
547 struct ppp *ppp = PF_TO_PPP(pf);
550 if (ppp->n_channels == 0 &&
551 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
552 mask |= POLLIN | POLLRDNORM;
553 ppp_recv_unlock(ppp);
559 #ifdef CONFIG_PPP_FILTER
560 static int get_filter(void __user *arg, struct sock_filter **p)
562 struct sock_fprog uprog;
563 struct sock_filter *code = NULL;
566 if (copy_from_user(&uprog, arg, sizeof(uprog)))
574 len = uprog.len * sizeof(struct sock_filter);
575 code = memdup_user(uprog.filter, len);
577 return PTR_ERR(code);
582 #endif /* CONFIG_PPP_FILTER */
584 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
588 int err = -EFAULT, val, val2, i;
589 struct ppp_idle idle;
592 struct slcompress *vj;
593 void __user *argp = (void __user *)arg;
594 int __user *p = argp;
596 mutex_lock(&ppp_mutex);
598 pf = file->private_data;
600 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
605 if (cmd == PPPIOCDETACH) {
607 * We have to be careful here... if the file descriptor
608 * has been dup'd, we could have another process in the
609 * middle of a poll using the same file *, so we had
610 * better not free the interface data structures -
611 * instead we fail the ioctl. Even in this case, we
612 * shut down the interface if we are the owner of it.
613 * Actually, we should get rid of PPPIOCDETACH, userland
614 * (i.e. pppd) could achieve the same effect by closing
615 * this fd and reopening /dev/ppp.
618 if (pf->kind == INTERFACE) {
621 if (file == ppp->owner)
622 unregister_netdevice(ppp->dev);
625 if (atomic_long_read(&file->f_count) < 2) {
626 ppp_release(NULL, file);
629 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
630 atomic_long_read(&file->f_count));
634 if (pf->kind == CHANNEL) {
636 struct ppp_channel *chan;
638 pch = PF_TO_CHANNEL(pf);
642 if (get_user(unit, p))
644 err = ppp_connect_channel(pch, unit);
648 err = ppp_disconnect_channel(pch);
652 down_read(&pch->chan_sem);
655 if (chan && chan->ops->ioctl)
656 err = chan->ops->ioctl(chan, cmd, arg);
657 up_read(&pch->chan_sem);
662 if (pf->kind != INTERFACE) {
664 pr_err("PPP: not interface or channel??\n");
672 if (get_user(val, p))
679 if (get_user(val, p))
682 cflags = ppp->flags & ~val;
683 #ifdef CONFIG_PPP_MULTILINK
684 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
687 ppp->flags = val & SC_FLAG_BITS;
689 if (cflags & SC_CCP_OPEN)
695 val = ppp->flags | ppp->xstate | ppp->rstate;
696 if (put_user(val, p))
701 case PPPIOCSCOMPRESS:
702 err = ppp_set_compress(ppp, arg);
706 if (put_user(ppp->file.index, p))
712 if (get_user(val, p))
719 if (put_user(ppp->debug, p))
725 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
726 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
727 if (copy_to_user(argp, &idle, sizeof(idle)))
733 if (get_user(val, p))
736 if ((val >> 16) != 0) {
740 vj = slhc_init(val2+1, val+1);
755 if (copy_from_user(&npi, argp, sizeof(npi)))
757 err = proto_to_npindex(npi.protocol);
761 if (cmd == PPPIOCGNPMODE) {
763 npi.mode = ppp->npmode[i];
764 if (copy_to_user(argp, &npi, sizeof(npi)))
767 ppp->npmode[i] = npi.mode;
768 /* we may be able to transmit more packets now (??) */
769 netif_wake_queue(ppp->dev);
774 #ifdef CONFIG_PPP_FILTER
777 struct sock_filter *code;
779 err = get_filter(argp, &code);
781 struct bpf_prog *pass_filter = NULL;
782 struct sock_fprog_kern fprog = {
789 err = bpf_prog_create(&pass_filter, &fprog);
792 if (ppp->pass_filter)
793 bpf_prog_destroy(ppp->pass_filter);
794 ppp->pass_filter = pass_filter;
803 struct sock_filter *code;
805 err = get_filter(argp, &code);
807 struct bpf_prog *active_filter = NULL;
808 struct sock_fprog_kern fprog = {
815 err = bpf_prog_create(&active_filter, &fprog);
818 if (ppp->active_filter)
819 bpf_prog_destroy(ppp->active_filter);
820 ppp->active_filter = active_filter;
827 #endif /* CONFIG_PPP_FILTER */
829 #ifdef CONFIG_PPP_MULTILINK
831 if (get_user(val, p))
835 ppp_recv_unlock(ppp);
838 #endif /* CONFIG_PPP_MULTILINK */
845 mutex_unlock(&ppp_mutex);
850 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
851 struct file *file, unsigned int cmd, unsigned long arg)
853 int unit, err = -EFAULT;
855 struct channel *chan;
857 int __user *p = (int __user *)arg;
861 /* Create a new ppp unit */
862 if (get_user(unit, p))
864 err = ppp_create_interface(net, file, &unit);
869 if (put_user(unit, p))
875 /* Attach to an existing ppp unit */
876 if (get_user(unit, p))
879 pn = ppp_pernet(net);
880 mutex_lock(&pn->all_ppp_mutex);
881 ppp = ppp_find_unit(pn, unit);
883 atomic_inc(&ppp->file.refcnt);
884 file->private_data = &ppp->file;
887 mutex_unlock(&pn->all_ppp_mutex);
891 if (get_user(unit, p))
894 pn = ppp_pernet(net);
895 spin_lock_bh(&pn->all_channels_lock);
896 chan = ppp_find_channel(pn, unit);
898 atomic_inc(&chan->file.refcnt);
899 file->private_data = &chan->file;
902 spin_unlock_bh(&pn->all_channels_lock);
912 static const struct file_operations ppp_device_fops = {
913 .owner = THIS_MODULE,
917 .unlocked_ioctl = ppp_ioctl,
919 .release = ppp_release,
920 .llseek = noop_llseek,
923 static __net_init int ppp_init_net(struct net *net)
925 struct ppp_net *pn = net_generic(net, ppp_net_id);
927 idr_init(&pn->units_idr);
928 mutex_init(&pn->all_ppp_mutex);
930 INIT_LIST_HEAD(&pn->all_channels);
931 INIT_LIST_HEAD(&pn->new_channels);
933 spin_lock_init(&pn->all_channels_lock);
938 static __net_exit void ppp_exit_net(struct net *net)
940 struct ppp_net *pn = net_generic(net, ppp_net_id);
941 struct net_device *dev;
942 struct net_device *aux;
948 for_each_netdev_safe(net, dev, aux) {
949 if (dev->netdev_ops == &ppp_netdev_ops)
950 unregister_netdevice_queue(dev, &list);
953 idr_for_each_entry(&pn->units_idr, ppp, id)
954 /* Skip devices already unregistered by previous loop */
955 if (!net_eq(dev_net(ppp->dev), net))
956 unregister_netdevice_queue(ppp->dev, &list);
958 unregister_netdevice_many(&list);
961 idr_destroy(&pn->units_idr);
964 static struct pernet_operations ppp_net_ops = {
965 .init = ppp_init_net,
966 .exit = ppp_exit_net,
968 .size = sizeof(struct ppp_net),
971 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
973 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
976 mutex_lock(&pn->all_ppp_mutex);
979 ret = unit_get(&pn->units_idr, ppp);
983 /* Caller asked for a specific unit number. Fail with -EEXIST
984 * if unavailable. For backward compatibility, return -EEXIST
985 * too if idr allocation fails; this makes pppd retry without
986 * requesting a specific unit number.
988 if (unit_find(&pn->units_idr, unit)) {
992 ret = unit_set(&pn->units_idr, ppp, unit);
994 /* Rewrite error for backward compatibility */
999 ppp->file.index = ret;
1002 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1004 ret = register_netdevice(ppp->dev);
1008 atomic_inc(&ppp_unit_count);
1010 mutex_unlock(&pn->all_ppp_mutex);
1015 unit_put(&pn->units_idr, ppp->file.index);
1017 mutex_unlock(&pn->all_ppp_mutex);
1022 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1023 const struct ppp_config *conf)
1025 struct ppp *ppp = netdev_priv(dev);
1030 ppp->ppp_net = src_net;
1032 ppp->owner = conf->file;
1034 init_ppp_file(&ppp->file, INTERFACE);
1035 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1037 for (indx = 0; indx < NUM_NP; ++indx)
1038 ppp->npmode[indx] = NPMODE_PASS;
1039 INIT_LIST_HEAD(&ppp->channels);
1040 spin_lock_init(&ppp->rlock);
1041 spin_lock_init(&ppp->wlock);
1042 #ifdef CONFIG_PPP_MULTILINK
1044 skb_queue_head_init(&ppp->mrq);
1045 #endif /* CONFIG_PPP_MULTILINK */
1046 #ifdef CONFIG_PPP_FILTER
1047 ppp->pass_filter = NULL;
1048 ppp->active_filter = NULL;
1049 #endif /* CONFIG_PPP_FILTER */
1051 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1055 conf->file->private_data = &ppp->file;
1060 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1061 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1064 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1065 struct netlink_ext_ack *extack)
1070 if (!data[IFLA_PPP_DEV_FD])
1072 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1078 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1079 struct nlattr *tb[], struct nlattr *data[],
1080 struct netlink_ext_ack *extack)
1082 struct ppp_config conf = {
1084 .ifname_is_set = true,
1089 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1093 /* rtnl_lock is already held here, but ppp_create_interface() locks
1094 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1095 * possible deadlock due to lock order inversion, at the cost of
1096 * pushing the problem back to userspace.
1098 if (!mutex_trylock(&ppp_mutex)) {
1103 if (file->f_op != &ppp_device_fops || file->private_data) {
1110 /* Don't use device name generated by the rtnetlink layer when ifname
1111 * isn't specified. Let ppp_dev_configure() set the device name using
1112 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1113 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1115 if (!tb[IFLA_IFNAME])
1116 conf.ifname_is_set = false;
1118 err = ppp_dev_configure(src_net, dev, &conf);
1121 mutex_unlock(&ppp_mutex);
1128 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1130 unregister_netdevice_queue(dev, head);
1133 static size_t ppp_nl_get_size(const struct net_device *dev)
1138 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1143 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1145 struct ppp *ppp = netdev_priv(dev);
1147 return ppp->ppp_net;
1150 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1152 .maxtype = IFLA_PPP_MAX,
1153 .policy = ppp_nl_policy,
1154 .priv_size = sizeof(struct ppp),
1156 .validate = ppp_nl_validate,
1157 .newlink = ppp_nl_newlink,
1158 .dellink = ppp_nl_dellink,
1159 .get_size = ppp_nl_get_size,
1160 .fill_info = ppp_nl_fill_info,
1161 .get_link_net = ppp_nl_get_link_net,
1164 #define PPP_MAJOR 108
1166 /* Called at boot time if ppp is compiled into the kernel,
1167 or at module load time (from init_module) if compiled as a module. */
1168 static int __init ppp_init(void)
1172 pr_info("PPP generic driver version " PPP_VERSION "\n");
1174 err = register_pernet_device(&ppp_net_ops);
1176 pr_err("failed to register PPP pernet device (%d)\n", err);
1180 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1182 pr_err("failed to register PPP device (%d)\n", err);
1186 ppp_class = class_create(THIS_MODULE, "ppp");
1187 if (IS_ERR(ppp_class)) {
1188 err = PTR_ERR(ppp_class);
1192 err = rtnl_link_register(&ppp_link_ops);
1194 pr_err("failed to register rtnetlink PPP handler\n");
1198 /* not a big deal if we fail here :-) */
1199 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1204 class_destroy(ppp_class);
1206 unregister_chrdev(PPP_MAJOR, "ppp");
1208 unregister_pernet_device(&ppp_net_ops);
1214 * Network interface unit routines.
1217 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1219 struct ppp *ppp = netdev_priv(dev);
1223 npi = ethertype_to_npindex(ntohs(skb->protocol));
1227 /* Drop, accept or reject the packet */
1228 switch (ppp->npmode[npi]) {
1232 /* it would be nice to have a way to tell the network
1233 system to queue this one up for later. */
1240 /* Put the 2-byte PPP protocol number on the front,
1241 making sure there is room for the address and control fields. */
1242 if (skb_cow_head(skb, PPP_HDRLEN))
1245 pp = skb_push(skb, 2);
1246 proto = npindex_to_proto[npi];
1247 put_unaligned_be16(proto, pp);
1249 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1250 skb_queue_tail(&ppp->file.xq, skb);
1251 ppp_xmit_process(ppp);
1252 return NETDEV_TX_OK;
1256 ++dev->stats.tx_dropped;
1257 return NETDEV_TX_OK;
1261 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1263 struct ppp *ppp = netdev_priv(dev);
1265 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1266 struct ppp_stats stats;
1267 struct ppp_comp_stats cstats;
1272 ppp_get_stats(ppp, &stats);
1273 if (copy_to_user(addr, &stats, sizeof(stats)))
1278 case SIOCGPPPCSTATS:
1279 memset(&cstats, 0, sizeof(cstats));
1281 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1283 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1284 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1291 if (copy_to_user(addr, vers, strlen(vers) + 1))
1304 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1306 struct ppp *ppp = netdev_priv(dev);
1309 stats64->rx_packets = ppp->stats64.rx_packets;
1310 stats64->rx_bytes = ppp->stats64.rx_bytes;
1311 ppp_recv_unlock(ppp);
1314 stats64->tx_packets = ppp->stats64.tx_packets;
1315 stats64->tx_bytes = ppp->stats64.tx_bytes;
1316 ppp_xmit_unlock(ppp);
1318 stats64->rx_errors = dev->stats.rx_errors;
1319 stats64->tx_errors = dev->stats.tx_errors;
1320 stats64->rx_dropped = dev->stats.rx_dropped;
1321 stats64->tx_dropped = dev->stats.tx_dropped;
1322 stats64->rx_length_errors = dev->stats.rx_length_errors;
1325 static int ppp_dev_init(struct net_device *dev)
1327 netdev_lockdep_set_classes(dev);
1331 static void ppp_dev_uninit(struct net_device *dev)
1333 struct ppp *ppp = netdev_priv(dev);
1334 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1340 mutex_lock(&pn->all_ppp_mutex);
1341 unit_put(&pn->units_idr, ppp->file.index);
1342 mutex_unlock(&pn->all_ppp_mutex);
1347 wake_up_interruptible(&ppp->file.rwait);
1350 static const struct net_device_ops ppp_netdev_ops = {
1351 .ndo_init = ppp_dev_init,
1352 .ndo_uninit = ppp_dev_uninit,
1353 .ndo_start_xmit = ppp_start_xmit,
1354 .ndo_do_ioctl = ppp_net_ioctl,
1355 .ndo_get_stats64 = ppp_get_stats64,
1358 static struct device_type ppp_type = {
1362 static void ppp_setup(struct net_device *dev)
1364 dev->netdev_ops = &ppp_netdev_ops;
1365 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1367 dev->features |= NETIF_F_LLTX;
1369 dev->hard_header_len = PPP_HDRLEN;
1372 dev->tx_queue_len = 3;
1373 dev->type = ARPHRD_PPP;
1374 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1375 netif_keep_dst(dev);
1379 * Transmit-side routines.
1382 /* Called to do any work queued up on the transmit side that can now be done */
1383 static void __ppp_xmit_process(struct ppp *ppp)
1385 struct sk_buff *skb;
1388 if (!ppp->closing) {
1390 while (!ppp->xmit_pending &&
1391 (skb = skb_dequeue(&ppp->file.xq)))
1392 ppp_send_frame(ppp, skb);
1393 /* If there's no work left to do, tell the core net
1394 code that we can accept some more. */
1395 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1396 netif_wake_queue(ppp->dev);
1398 netif_stop_queue(ppp->dev);
1400 ppp_xmit_unlock(ppp);
1403 static DEFINE_PER_CPU(int, ppp_xmit_recursion);
1405 static void ppp_xmit_process(struct ppp *ppp)
1409 if (unlikely(__this_cpu_read(ppp_xmit_recursion)))
1412 __this_cpu_inc(ppp_xmit_recursion);
1413 __ppp_xmit_process(ppp);
1414 __this_cpu_dec(ppp_xmit_recursion);
1423 if (net_ratelimit())
1424 netdev_err(ppp->dev, "recursion detected\n");
1427 static inline struct sk_buff *
1428 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1430 struct sk_buff *new_skb;
1432 int new_skb_size = ppp->dev->mtu +
1433 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1434 int compressor_skb_size = ppp->dev->mtu +
1435 ppp->xcomp->comp_extra + PPP_HDRLEN;
1436 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1438 if (net_ratelimit())
1439 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1442 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1443 skb_reserve(new_skb,
1444 ppp->dev->hard_header_len - PPP_HDRLEN);
1446 /* compressor still expects A/C bytes in hdr */
1447 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1448 new_skb->data, skb->len + 2,
1449 compressor_skb_size);
1450 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1454 skb_pull(skb, 2); /* pull off A/C bytes */
1455 } else if (len == 0) {
1456 /* didn't compress, or CCP not up yet */
1457 consume_skb(new_skb);
1462 * MPPE requires that we do not send unencrypted
1463 * frames. The compressor will return -1 if we
1464 * should drop the frame. We cannot simply test
1465 * the compress_proto because MPPE and MPPC share
1468 if (net_ratelimit())
1469 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1471 consume_skb(new_skb);
1478 * Compress and send a frame.
1479 * The caller should have locked the xmit path,
1480 * and xmit_pending should be 0.
1483 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1485 int proto = PPP_PROTO(skb);
1486 struct sk_buff *new_skb;
1490 if (proto < 0x8000) {
1491 #ifdef CONFIG_PPP_FILTER
1492 /* check if we should pass this packet */
1493 /* the filter instructions are constructed assuming
1494 a four-byte PPP header on each packet */
1495 *(u8 *)skb_push(skb, 2) = 1;
1496 if (ppp->pass_filter &&
1497 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1499 netdev_printk(KERN_DEBUG, ppp->dev,
1500 "PPP: outbound frame "
1505 /* if this packet passes the active filter, record the time */
1506 if (!(ppp->active_filter &&
1507 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1508 ppp->last_xmit = jiffies;
1511 /* for data packets, record the time */
1512 ppp->last_xmit = jiffies;
1513 #endif /* CONFIG_PPP_FILTER */
1516 ++ppp->stats64.tx_packets;
1517 ppp->stats64.tx_bytes += skb->len - 2;
1521 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1523 /* try to do VJ TCP header compression */
1524 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1527 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1530 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1532 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1533 new_skb->data + 2, &cp,
1534 !(ppp->flags & SC_NO_TCP_CCID));
1535 if (cp == skb->data + 2) {
1536 /* didn't compress */
1537 consume_skb(new_skb);
1539 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1540 proto = PPP_VJC_COMP;
1541 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1543 proto = PPP_VJC_UNCOMP;
1544 cp[0] = skb->data[2];
1548 cp = skb_put(skb, len + 2);
1555 /* peek at outbound CCP frames */
1556 ppp_ccp_peek(ppp, skb, 0);
1560 /* try to do packet compression */
1561 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1562 proto != PPP_LCP && proto != PPP_CCP) {
1563 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1564 if (net_ratelimit())
1565 netdev_err(ppp->dev,
1566 "ppp: compression required but "
1567 "down - pkt dropped.\n");
1570 skb = pad_compress_skb(ppp, skb);
1576 * If we are waiting for traffic (demand dialling),
1577 * queue it up for pppd to receive.
1579 if (ppp->flags & SC_LOOP_TRAFFIC) {
1580 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1582 skb_queue_tail(&ppp->file.rq, skb);
1583 wake_up_interruptible(&ppp->file.rwait);
1587 ppp->xmit_pending = skb;
1593 ++ppp->dev->stats.tx_errors;
1597 * Try to send the frame in xmit_pending.
1598 * The caller should have the xmit path locked.
1601 ppp_push(struct ppp *ppp)
1603 struct list_head *list;
1604 struct channel *pch;
1605 struct sk_buff *skb = ppp->xmit_pending;
1610 list = &ppp->channels;
1611 if (list_empty(list)) {
1612 /* nowhere to send the packet, just drop it */
1613 ppp->xmit_pending = NULL;
1618 if ((ppp->flags & SC_MULTILINK) == 0) {
1619 /* not doing multilink: send it down the first channel */
1621 pch = list_entry(list, struct channel, clist);
1623 spin_lock(&pch->downl);
1625 if (pch->chan->ops->start_xmit(pch->chan, skb))
1626 ppp->xmit_pending = NULL;
1628 /* channel got unregistered */
1630 ppp->xmit_pending = NULL;
1632 spin_unlock(&pch->downl);
1636 #ifdef CONFIG_PPP_MULTILINK
1637 /* Multilink: fragment the packet over as many links
1638 as can take the packet at the moment. */
1639 if (!ppp_mp_explode(ppp, skb))
1641 #endif /* CONFIG_PPP_MULTILINK */
1643 ppp->xmit_pending = NULL;
1647 #ifdef CONFIG_PPP_MULTILINK
1648 static bool mp_protocol_compress __read_mostly = true;
1649 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1650 MODULE_PARM_DESC(mp_protocol_compress,
1651 "compress protocol id in multilink fragments");
1654 * Divide a packet to be transmitted into fragments and
1655 * send them out the individual links.
1657 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1660 int i, bits, hdrlen, mtu;
1662 int navail, nfree, nzero;
1666 unsigned char *p, *q;
1667 struct list_head *list;
1668 struct channel *pch;
1669 struct sk_buff *frag;
1670 struct ppp_channel *chan;
1672 totspeed = 0; /*total bitrate of the bundle*/
1673 nfree = 0; /* # channels which have no packet already queued */
1674 navail = 0; /* total # of usable channels (not deregistered) */
1675 nzero = 0; /* number of channels with zero speed associated*/
1676 totfree = 0; /*total # of channels available and
1677 *having no queued packets before
1678 *starting the fragmentation*/
1680 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1682 list_for_each_entry(pch, &ppp->channels, clist) {
1686 pch->speed = pch->chan->speed;
1691 if (skb_queue_empty(&pch->file.xq) ||
1693 if (pch->speed == 0)
1696 totspeed += pch->speed;
1702 if (!pch->had_frag && i < ppp->nxchan)
1708 * Don't start sending this packet unless at least half of
1709 * the channels are free. This gives much better TCP
1710 * performance if we have a lot of channels.
1712 if (nfree == 0 || nfree < navail / 2)
1713 return 0; /* can't take now, leave it in xmit_pending */
1715 /* Do protocol field compression */
1718 if (*p == 0 && mp_protocol_compress) {
1724 nbigger = len % nfree;
1726 /* skip to the channel after the one we last used
1727 and start at that one */
1728 list = &ppp->channels;
1729 for (i = 0; i < ppp->nxchan; ++i) {
1731 if (list == &ppp->channels) {
1737 /* create a fragment for each channel */
1741 if (list == &ppp->channels) {
1745 pch = list_entry(list, struct channel, clist);
1751 * Skip this channel if it has a fragment pending already and
1752 * we haven't given a fragment to all of the free channels.
1754 if (pch->avail == 1) {
1761 /* check the channel's mtu and whether it is still attached. */
1762 spin_lock(&pch->downl);
1763 if (pch->chan == NULL) {
1764 /* can't use this channel, it's being deregistered */
1765 if (pch->speed == 0)
1768 totspeed -= pch->speed;
1770 spin_unlock(&pch->downl);
1781 *if the channel speed is not set divide
1782 *the packet evenly among the free channels;
1783 *otherwise divide it according to the speed
1784 *of the channel we are going to transmit on
1788 if (pch->speed == 0) {
1795 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1796 ((totspeed*totfree)/pch->speed)) - hdrlen;
1798 flen += ((totfree - nzero)*pch->speed)/totspeed;
1799 nbigger -= ((totfree - nzero)*pch->speed)/
1807 *check if we are on the last channel or
1808 *we exceded the length of the data to
1811 if ((nfree <= 0) || (flen > len))
1814 *it is not worth to tx on slow channels:
1815 *in that case from the resulting flen according to the
1816 *above formula will be equal or less than zero.
1817 *Skip the channel in this case
1821 spin_unlock(&pch->downl);
1826 * hdrlen includes the 2-byte PPP protocol field, but the
1827 * MTU counts only the payload excluding the protocol field.
1828 * (RFC1661 Section 2)
1830 mtu = pch->chan->mtu - (hdrlen - 2);
1837 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1840 q = skb_put(frag, flen + hdrlen);
1842 /* make the MP header */
1843 put_unaligned_be16(PPP_MP, q);
1844 if (ppp->flags & SC_MP_XSHORTSEQ) {
1845 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1849 q[3] = ppp->nxseq >> 16;
1850 q[4] = ppp->nxseq >> 8;
1854 memcpy(q + hdrlen, p, flen);
1856 /* try to send it down the channel */
1858 if (!skb_queue_empty(&pch->file.xq) ||
1859 !chan->ops->start_xmit(chan, frag))
1860 skb_queue_tail(&pch->file.xq, frag);
1866 spin_unlock(&pch->downl);
1873 spin_unlock(&pch->downl);
1875 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1876 ++ppp->dev->stats.tx_errors;
1878 return 1; /* abandon the frame */
1880 #endif /* CONFIG_PPP_MULTILINK */
1882 /* Try to send data out on a channel */
1883 static void __ppp_channel_push(struct channel *pch)
1885 struct sk_buff *skb;
1888 spin_lock(&pch->downl);
1890 while (!skb_queue_empty(&pch->file.xq)) {
1891 skb = skb_dequeue(&pch->file.xq);
1892 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1893 /* put the packet back and try again later */
1894 skb_queue_head(&pch->file.xq, skb);
1899 /* channel got deregistered */
1900 skb_queue_purge(&pch->file.xq);
1902 spin_unlock(&pch->downl);
1903 /* see if there is anything from the attached unit to be sent */
1904 if (skb_queue_empty(&pch->file.xq)) {
1905 read_lock(&pch->upl);
1908 __ppp_xmit_process(ppp);
1909 read_unlock(&pch->upl);
1913 static void ppp_channel_push(struct channel *pch)
1917 __this_cpu_inc(ppp_xmit_recursion);
1918 __ppp_channel_push(pch);
1919 __this_cpu_dec(ppp_xmit_recursion);
1925 * Receive-side routines.
1928 struct ppp_mp_skb_parm {
1932 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1935 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1939 ppp_receive_frame(ppp, skb, pch);
1942 ppp_recv_unlock(ppp);
1946 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1948 struct channel *pch = chan->ppp;
1956 read_lock_bh(&pch->upl);
1957 if (!pskb_may_pull(skb, 2)) {
1960 ++pch->ppp->dev->stats.rx_length_errors;
1961 ppp_receive_error(pch->ppp);
1966 proto = PPP_PROTO(skb);
1967 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1968 /* put it on the channel queue */
1969 skb_queue_tail(&pch->file.rq, skb);
1970 /* drop old frames if queue too long */
1971 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1972 (skb = skb_dequeue(&pch->file.rq)))
1974 wake_up_interruptible(&pch->file.rwait);
1976 ppp_do_recv(pch->ppp, skb, pch);
1980 read_unlock_bh(&pch->upl);
1983 /* Put a 0-length skb in the receive queue as an error indication */
1985 ppp_input_error(struct ppp_channel *chan, int code)
1987 struct channel *pch = chan->ppp;
1988 struct sk_buff *skb;
1993 read_lock_bh(&pch->upl);
1995 skb = alloc_skb(0, GFP_ATOMIC);
1997 skb->len = 0; /* probably unnecessary */
1999 ppp_do_recv(pch->ppp, skb, pch);
2002 read_unlock_bh(&pch->upl);
2006 * We come in here to process a received frame.
2007 * The receive side of the ppp unit is locked.
2010 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2012 /* note: a 0-length skb is used as an error indication */
2014 skb_checksum_complete_unset(skb);
2015 #ifdef CONFIG_PPP_MULTILINK
2016 /* XXX do channel-level decompression here */
2017 if (PPP_PROTO(skb) == PPP_MP)
2018 ppp_receive_mp_frame(ppp, skb, pch);
2020 #endif /* CONFIG_PPP_MULTILINK */
2021 ppp_receive_nonmp_frame(ppp, skb);
2024 ppp_receive_error(ppp);
2029 ppp_receive_error(struct ppp *ppp)
2031 ++ppp->dev->stats.rx_errors;
2037 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2040 int proto, len, npi;
2043 * Decompress the frame, if compressed.
2044 * Note that some decompressors need to see uncompressed frames
2045 * that come in as well as compressed frames.
2047 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2048 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2049 skb = ppp_decompress_frame(ppp, skb);
2051 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2054 proto = PPP_PROTO(skb);
2057 /* decompress VJ compressed packets */
2058 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2061 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2062 /* copy to a new sk_buff with more tailroom */
2063 ns = dev_alloc_skb(skb->len + 128);
2065 netdev_err(ppp->dev, "PPP: no memory "
2070 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2075 skb->ip_summed = CHECKSUM_NONE;
2077 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2079 netdev_printk(KERN_DEBUG, ppp->dev,
2080 "PPP: VJ decompression error\n");
2085 skb_put(skb, len - skb->len);
2086 else if (len < skb->len)
2091 case PPP_VJC_UNCOMP:
2092 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2095 /* Until we fix the decompressor need to make sure
2096 * data portion is linear.
2098 if (!pskb_may_pull(skb, skb->len))
2101 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2102 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2109 ppp_ccp_peek(ppp, skb, 1);
2113 ++ppp->stats64.rx_packets;
2114 ppp->stats64.rx_bytes += skb->len - 2;
2116 npi = proto_to_npindex(proto);
2118 /* control or unknown frame - pass it to pppd */
2119 skb_queue_tail(&ppp->file.rq, skb);
2120 /* limit queue length by dropping old frames */
2121 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2122 (skb = skb_dequeue(&ppp->file.rq)))
2124 /* wake up any process polling or blocking on read */
2125 wake_up_interruptible(&ppp->file.rwait);
2128 /* network protocol frame - give it to the kernel */
2130 #ifdef CONFIG_PPP_FILTER
2131 /* check if the packet passes the pass and active filters */
2132 /* the filter instructions are constructed assuming
2133 a four-byte PPP header on each packet */
2134 if (ppp->pass_filter || ppp->active_filter) {
2135 if (skb_unclone(skb, GFP_ATOMIC))
2138 *(u8 *)skb_push(skb, 2) = 0;
2139 if (ppp->pass_filter &&
2140 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2142 netdev_printk(KERN_DEBUG, ppp->dev,
2143 "PPP: inbound frame "
2148 if (!(ppp->active_filter &&
2149 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2150 ppp->last_recv = jiffies;
2153 #endif /* CONFIG_PPP_FILTER */
2154 ppp->last_recv = jiffies;
2156 if ((ppp->dev->flags & IFF_UP) == 0 ||
2157 ppp->npmode[npi] != NPMODE_PASS) {
2160 /* chop off protocol */
2161 skb_pull_rcsum(skb, 2);
2162 skb->dev = ppp->dev;
2163 skb->protocol = htons(npindex_to_ethertype[npi]);
2164 skb_reset_mac_header(skb);
2165 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2166 dev_net(ppp->dev)));
2174 ppp_receive_error(ppp);
2177 static struct sk_buff *
2178 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2180 int proto = PPP_PROTO(skb);
2184 /* Until we fix all the decompressor's need to make sure
2185 * data portion is linear.
2187 if (!pskb_may_pull(skb, skb->len))
2190 if (proto == PPP_COMP) {
2193 switch(ppp->rcomp->compress_proto) {
2195 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2198 obuff_size = ppp->mru + PPP_HDRLEN;
2202 ns = dev_alloc_skb(obuff_size);
2204 netdev_err(ppp->dev, "ppp_decompress_frame: "
2208 /* the decompressor still expects the A/C bytes in the hdr */
2209 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2210 skb->len + 2, ns->data, obuff_size);
2212 /* Pass the compressed frame to pppd as an
2213 error indication. */
2214 if (len == DECOMP_FATALERROR)
2215 ppp->rstate |= SC_DC_FERROR;
2223 skb_pull(skb, 2); /* pull off the A/C bytes */
2226 /* Uncompressed frame - pass to decompressor so it
2227 can update its dictionary if necessary. */
2228 if (ppp->rcomp->incomp)
2229 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2236 ppp->rstate |= SC_DC_ERROR;
2237 ppp_receive_error(ppp);
2241 #ifdef CONFIG_PPP_MULTILINK
2243 * Receive a multilink frame.
2244 * We put it on the reconstruction queue and then pull off
2245 * as many completed frames as we can.
2248 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2252 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2254 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2255 goto err; /* no good, throw it away */
2257 /* Decode sequence number and begin/end bits */
2258 if (ppp->flags & SC_MP_SHORTSEQ) {
2259 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2262 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2265 PPP_MP_CB(skb)->BEbits = skb->data[2];
2266 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2269 * Do protocol ID decompression on the first fragment of each packet.
2271 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2272 *(u8 *)skb_push(skb, 1) = 0;
2275 * Expand sequence number to 32 bits, making it as close
2276 * as possible to ppp->minseq.
2278 seq |= ppp->minseq & ~mask;
2279 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2281 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2282 seq -= mask + 1; /* should never happen */
2283 PPP_MP_CB(skb)->sequence = seq;
2287 * If this packet comes before the next one we were expecting,
2290 if (seq_before(seq, ppp->nextseq)) {
2292 ++ppp->dev->stats.rx_dropped;
2293 ppp_receive_error(ppp);
2298 * Reevaluate minseq, the minimum over all channels of the
2299 * last sequence number received on each channel. Because of
2300 * the increasing sequence number rule, we know that any fragment
2301 * before `minseq' which hasn't arrived is never going to arrive.
2302 * The list of channels can't change because we have the receive
2303 * side of the ppp unit locked.
2305 list_for_each_entry(ch, &ppp->channels, clist) {
2306 if (seq_before(ch->lastseq, seq))
2309 if (seq_before(ppp->minseq, seq))
2312 /* Put the fragment on the reconstruction queue */
2313 ppp_mp_insert(ppp, skb);
2315 /* If the queue is getting long, don't wait any longer for packets
2316 before the start of the queue. */
2317 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2318 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2319 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2320 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2323 /* Pull completed packets off the queue and receive them. */
2324 while ((skb = ppp_mp_reconstruct(ppp))) {
2325 if (pskb_may_pull(skb, 2))
2326 ppp_receive_nonmp_frame(ppp, skb);
2328 ++ppp->dev->stats.rx_length_errors;
2330 ppp_receive_error(ppp);
2338 ppp_receive_error(ppp);
2342 * Insert a fragment on the MP reconstruction queue.
2343 * The queue is ordered by increasing sequence number.
2346 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2349 struct sk_buff_head *list = &ppp->mrq;
2350 u32 seq = PPP_MP_CB(skb)->sequence;
2352 /* N.B. we don't need to lock the list lock because we have the
2353 ppp unit receive-side lock. */
2354 skb_queue_walk(list, p) {
2355 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2358 __skb_queue_before(list, p, skb);
2362 * Reconstruct a packet from the MP fragment queue.
2363 * We go through increasing sequence numbers until we find a
2364 * complete packet, or we get to the sequence number for a fragment
2365 * which hasn't arrived but might still do so.
2367 static struct sk_buff *
2368 ppp_mp_reconstruct(struct ppp *ppp)
2370 u32 seq = ppp->nextseq;
2371 u32 minseq = ppp->minseq;
2372 struct sk_buff_head *list = &ppp->mrq;
2373 struct sk_buff *p, *tmp;
2374 struct sk_buff *head, *tail;
2375 struct sk_buff *skb = NULL;
2376 int lost = 0, len = 0;
2378 if (ppp->mrru == 0) /* do nothing until mrru is set */
2382 skb_queue_walk_safe(list, p, tmp) {
2384 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2385 /* this can't happen, anyway ignore the skb */
2386 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2388 PPP_MP_CB(p)->sequence, seq);
2389 __skb_unlink(p, list);
2393 if (PPP_MP_CB(p)->sequence != seq) {
2395 /* Fragment `seq' is missing. If it is after
2396 minseq, it might arrive later, so stop here. */
2397 if (seq_after(seq, minseq))
2399 /* Fragment `seq' is lost, keep going. */
2402 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2403 minseq + 1: PPP_MP_CB(p)->sequence;
2406 netdev_printk(KERN_DEBUG, ppp->dev,
2407 "lost frag %u..%u\n",
2414 * At this point we know that all the fragments from
2415 * ppp->nextseq to seq are either present or lost.
2416 * Also, there are no complete packets in the queue
2417 * that have no missing fragments and end before this
2421 /* B bit set indicates this fragment starts a packet */
2422 if (PPP_MP_CB(p)->BEbits & B) {
2430 /* Got a complete packet yet? */
2431 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2432 (PPP_MP_CB(head)->BEbits & B)) {
2433 if (len > ppp->mrru + 2) {
2434 ++ppp->dev->stats.rx_length_errors;
2435 netdev_printk(KERN_DEBUG, ppp->dev,
2436 "PPP: reconstructed packet"
2437 " is too long (%d)\n", len);
2442 ppp->nextseq = seq + 1;
2446 * If this is the ending fragment of a packet,
2447 * and we haven't found a complete valid packet yet,
2448 * we can discard up to and including this fragment.
2450 if (PPP_MP_CB(p)->BEbits & E) {
2451 struct sk_buff *tmp2;
2453 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2455 netdev_printk(KERN_DEBUG, ppp->dev,
2456 "discarding frag %u\n",
2457 PPP_MP_CB(p)->sequence);
2458 __skb_unlink(p, list);
2461 head = skb_peek(list);
2468 /* If we have a complete packet, copy it all into one skb. */
2470 /* If we have discarded any fragments,
2471 signal a receive error. */
2472 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2473 skb_queue_walk_safe(list, p, tmp) {
2477 netdev_printk(KERN_DEBUG, ppp->dev,
2478 "discarding frag %u\n",
2479 PPP_MP_CB(p)->sequence);
2480 __skb_unlink(p, list);
2485 netdev_printk(KERN_DEBUG, ppp->dev,
2486 " missed pkts %u..%u\n",
2488 PPP_MP_CB(head)->sequence-1);
2489 ++ppp->dev->stats.rx_dropped;
2490 ppp_receive_error(ppp);
2495 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2496 p = skb_queue_next(list, head);
2497 __skb_unlink(skb, list);
2498 skb_queue_walk_from_safe(list, p, tmp) {
2499 __skb_unlink(p, list);
2505 skb->data_len += p->len;
2506 skb->truesize += p->truesize;
2512 __skb_unlink(skb, list);
2515 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2520 #endif /* CONFIG_PPP_MULTILINK */
2523 * Channel interface.
2526 /* Create a new, unattached ppp channel. */
2527 int ppp_register_channel(struct ppp_channel *chan)
2529 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2532 /* Create a new, unattached ppp channel for specified net. */
2533 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2535 struct channel *pch;
2538 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2542 pn = ppp_pernet(net);
2546 pch->chan_net = get_net(net);
2548 init_ppp_file(&pch->file, CHANNEL);
2549 pch->file.hdrlen = chan->hdrlen;
2550 #ifdef CONFIG_PPP_MULTILINK
2552 #endif /* CONFIG_PPP_MULTILINK */
2553 init_rwsem(&pch->chan_sem);
2554 spin_lock_init(&pch->downl);
2555 rwlock_init(&pch->upl);
2557 spin_lock_bh(&pn->all_channels_lock);
2558 pch->file.index = ++pn->last_channel_index;
2559 list_add(&pch->list, &pn->new_channels);
2560 atomic_inc(&channel_count);
2561 spin_unlock_bh(&pn->all_channels_lock);
2567 * Return the index of a channel.
2569 int ppp_channel_index(struct ppp_channel *chan)
2571 struct channel *pch = chan->ppp;
2574 return pch->file.index;
2579 * Return the PPP unit number to which a channel is connected.
2581 int ppp_unit_number(struct ppp_channel *chan)
2583 struct channel *pch = chan->ppp;
2587 read_lock_bh(&pch->upl);
2589 unit = pch->ppp->file.index;
2590 read_unlock_bh(&pch->upl);
2596 * Return the PPP device interface name of a channel.
2598 char *ppp_dev_name(struct ppp_channel *chan)
2600 struct channel *pch = chan->ppp;
2604 read_lock_bh(&pch->upl);
2605 if (pch->ppp && pch->ppp->dev)
2606 name = pch->ppp->dev->name;
2607 read_unlock_bh(&pch->upl);
2614 * Disconnect a channel from the generic layer.
2615 * This must be called in process context.
2618 ppp_unregister_channel(struct ppp_channel *chan)
2620 struct channel *pch = chan->ppp;
2624 return; /* should never happen */
2629 * This ensures that we have returned from any calls into the
2630 * the channel's start_xmit or ioctl routine before we proceed.
2632 down_write(&pch->chan_sem);
2633 spin_lock_bh(&pch->downl);
2635 spin_unlock_bh(&pch->downl);
2636 up_write(&pch->chan_sem);
2637 ppp_disconnect_channel(pch);
2639 pn = ppp_pernet(pch->chan_net);
2640 spin_lock_bh(&pn->all_channels_lock);
2641 list_del(&pch->list);
2642 spin_unlock_bh(&pn->all_channels_lock);
2645 wake_up_interruptible(&pch->file.rwait);
2646 if (atomic_dec_and_test(&pch->file.refcnt))
2647 ppp_destroy_channel(pch);
2651 * Callback from a channel when it can accept more to transmit.
2652 * This should be called at BH/softirq level, not interrupt level.
2655 ppp_output_wakeup(struct ppp_channel *chan)
2657 struct channel *pch = chan->ppp;
2661 ppp_channel_push(pch);
2665 * Compression control.
2668 /* Process the PPPIOCSCOMPRESS ioctl. */
2670 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2673 struct compressor *cp, *ocomp;
2674 struct ppp_option_data data;
2675 void *state, *ostate;
2676 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2679 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2681 if (data.length > CCP_MAX_OPTION_LENGTH)
2683 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2687 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2690 cp = try_then_request_module(
2691 find_compressor(ccp_option[0]),
2692 "ppp-compress-%d", ccp_option[0]);
2697 if (data.transmit) {
2698 state = cp->comp_alloc(ccp_option, data.length);
2701 ppp->xstate &= ~SC_COMP_RUN;
2703 ostate = ppp->xc_state;
2705 ppp->xc_state = state;
2706 ppp_xmit_unlock(ppp);
2708 ocomp->comp_free(ostate);
2709 module_put(ocomp->owner);
2713 module_put(cp->owner);
2716 state = cp->decomp_alloc(ccp_option, data.length);
2719 ppp->rstate &= ~SC_DECOMP_RUN;
2721 ostate = ppp->rc_state;
2723 ppp->rc_state = state;
2724 ppp_recv_unlock(ppp);
2726 ocomp->decomp_free(ostate);
2727 module_put(ocomp->owner);
2731 module_put(cp->owner);
2739 * Look at a CCP packet and update our state accordingly.
2740 * We assume the caller has the xmit or recv path locked.
2743 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2748 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2749 return; /* no header */
2752 switch (CCP_CODE(dp)) {
2755 /* A ConfReq starts negotiation of compression
2756 * in one direction of transmission,
2757 * and hence brings it down...but which way?
2760 * A ConfReq indicates what the sender would like to receive
2763 /* He is proposing what I should send */
2764 ppp->xstate &= ~SC_COMP_RUN;
2766 /* I am proposing to what he should send */
2767 ppp->rstate &= ~SC_DECOMP_RUN;
2774 * CCP is going down, both directions of transmission
2776 ppp->rstate &= ~SC_DECOMP_RUN;
2777 ppp->xstate &= ~SC_COMP_RUN;
2781 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2783 len = CCP_LENGTH(dp);
2784 if (!pskb_may_pull(skb, len + 2))
2785 return; /* too short */
2788 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2791 /* we will start receiving compressed packets */
2794 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2795 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2796 ppp->rstate |= SC_DECOMP_RUN;
2797 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2800 /* we will soon start sending compressed packets */
2803 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2804 ppp->file.index, 0, ppp->debug))
2805 ppp->xstate |= SC_COMP_RUN;
2810 /* reset the [de]compressor */
2811 if ((ppp->flags & SC_CCP_UP) == 0)
2814 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2815 ppp->rcomp->decomp_reset(ppp->rc_state);
2816 ppp->rstate &= ~SC_DC_ERROR;
2819 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2820 ppp->xcomp->comp_reset(ppp->xc_state);
2826 /* Free up compression resources. */
2828 ppp_ccp_closed(struct ppp *ppp)
2830 void *xstate, *rstate;
2831 struct compressor *xcomp, *rcomp;
2834 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2837 xstate = ppp->xc_state;
2838 ppp->xc_state = NULL;
2841 rstate = ppp->rc_state;
2842 ppp->rc_state = NULL;
2846 xcomp->comp_free(xstate);
2847 module_put(xcomp->owner);
2850 rcomp->decomp_free(rstate);
2851 module_put(rcomp->owner);
2855 /* List of compressors. */
2856 static LIST_HEAD(compressor_list);
2857 static DEFINE_SPINLOCK(compressor_list_lock);
2859 struct compressor_entry {
2860 struct list_head list;
2861 struct compressor *comp;
2864 static struct compressor_entry *
2865 find_comp_entry(int proto)
2867 struct compressor_entry *ce;
2869 list_for_each_entry(ce, &compressor_list, list) {
2870 if (ce->comp->compress_proto == proto)
2876 /* Register a compressor */
2878 ppp_register_compressor(struct compressor *cp)
2880 struct compressor_entry *ce;
2882 spin_lock(&compressor_list_lock);
2884 if (find_comp_entry(cp->compress_proto))
2887 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2892 list_add(&ce->list, &compressor_list);
2894 spin_unlock(&compressor_list_lock);
2898 /* Unregister a compressor */
2900 ppp_unregister_compressor(struct compressor *cp)
2902 struct compressor_entry *ce;
2904 spin_lock(&compressor_list_lock);
2905 ce = find_comp_entry(cp->compress_proto);
2906 if (ce && ce->comp == cp) {
2907 list_del(&ce->list);
2910 spin_unlock(&compressor_list_lock);
2913 /* Find a compressor. */
2914 static struct compressor *
2915 find_compressor(int type)
2917 struct compressor_entry *ce;
2918 struct compressor *cp = NULL;
2920 spin_lock(&compressor_list_lock);
2921 ce = find_comp_entry(type);
2924 if (!try_module_get(cp->owner))
2927 spin_unlock(&compressor_list_lock);
2932 * Miscelleneous stuff.
2936 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2938 struct slcompress *vj = ppp->vj;
2940 memset(st, 0, sizeof(*st));
2941 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2942 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2943 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2944 st->p.ppp_opackets = ppp->stats64.tx_packets;
2945 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2946 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2949 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2950 st->vj.vjs_compressed = vj->sls_o_compressed;
2951 st->vj.vjs_searches = vj->sls_o_searches;
2952 st->vj.vjs_misses = vj->sls_o_misses;
2953 st->vj.vjs_errorin = vj->sls_i_error;
2954 st->vj.vjs_tossed = vj->sls_i_tossed;
2955 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2956 st->vj.vjs_compressedin = vj->sls_i_compressed;
2960 * Stuff for handling the lists of ppp units and channels
2961 * and for initialization.
2965 * Create a new ppp interface unit. Fails if it can't allocate memory
2966 * or if there is already a unit with the requested number.
2967 * unit == -1 means allocate a new number.
2969 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
2971 struct ppp_config conf = {
2974 .ifname_is_set = false,
2976 struct net_device *dev;
2980 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
2985 dev_net_set(dev, net);
2986 dev->rtnl_link_ops = &ppp_link_ops;
2990 err = ppp_dev_configure(net, dev, &conf);
2993 ppp = netdev_priv(dev);
2994 *unit = ppp->file.index;
3008 * Initialize a ppp_file structure.
3011 init_ppp_file(struct ppp_file *pf, int kind)
3014 skb_queue_head_init(&pf->xq);
3015 skb_queue_head_init(&pf->rq);
3016 atomic_set(&pf->refcnt, 1);
3017 init_waitqueue_head(&pf->rwait);
3021 * Free the memory used by a ppp unit. This is only called once
3022 * there are no channels connected to the unit and no file structs
3023 * that reference the unit.
3025 static void ppp_destroy_interface(struct ppp *ppp)
3027 atomic_dec(&ppp_unit_count);
3029 if (!ppp->file.dead || ppp->n_channels) {
3030 /* "can't happen" */
3031 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3032 "but dead=%d n_channels=%d !\n",
3033 ppp, ppp->file.dead, ppp->n_channels);
3037 ppp_ccp_closed(ppp);
3042 skb_queue_purge(&ppp->file.xq);
3043 skb_queue_purge(&ppp->file.rq);
3044 #ifdef CONFIG_PPP_MULTILINK
3045 skb_queue_purge(&ppp->mrq);
3046 #endif /* CONFIG_PPP_MULTILINK */
3047 #ifdef CONFIG_PPP_FILTER
3048 if (ppp->pass_filter) {
3049 bpf_prog_destroy(ppp->pass_filter);
3050 ppp->pass_filter = NULL;
3053 if (ppp->active_filter) {
3054 bpf_prog_destroy(ppp->active_filter);
3055 ppp->active_filter = NULL;
3057 #endif /* CONFIG_PPP_FILTER */
3059 kfree_skb(ppp->xmit_pending);
3061 free_netdev(ppp->dev);
3065 * Locate an existing ppp unit.
3066 * The caller should have locked the all_ppp_mutex.
3069 ppp_find_unit(struct ppp_net *pn, int unit)
3071 return unit_find(&pn->units_idr, unit);
3075 * Locate an existing ppp channel.
3076 * The caller should have locked the all_channels_lock.
3077 * First we look in the new_channels list, then in the
3078 * all_channels list. If found in the new_channels list,
3079 * we move it to the all_channels list. This is for speed
3080 * when we have a lot of channels in use.
3082 static struct channel *
3083 ppp_find_channel(struct ppp_net *pn, int unit)
3085 struct channel *pch;
3087 list_for_each_entry(pch, &pn->new_channels, list) {
3088 if (pch->file.index == unit) {
3089 list_move(&pch->list, &pn->all_channels);
3094 list_for_each_entry(pch, &pn->all_channels, list) {
3095 if (pch->file.index == unit)
3103 * Connect a PPP channel to a PPP interface unit.
3106 ppp_connect_channel(struct channel *pch, int unit)
3113 pn = ppp_pernet(pch->chan_net);
3115 mutex_lock(&pn->all_ppp_mutex);
3116 ppp = ppp_find_unit(pn, unit);
3119 write_lock_bh(&pch->upl);
3125 if (pch->file.hdrlen > ppp->file.hdrlen)
3126 ppp->file.hdrlen = pch->file.hdrlen;
3127 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3128 if (hdrlen > ppp->dev->hard_header_len)
3129 ppp->dev->hard_header_len = hdrlen;
3130 list_add_tail(&pch->clist, &ppp->channels);
3133 atomic_inc(&ppp->file.refcnt);
3138 write_unlock_bh(&pch->upl);
3140 mutex_unlock(&pn->all_ppp_mutex);
3145 * Disconnect a channel from its ppp unit.
3148 ppp_disconnect_channel(struct channel *pch)
3153 write_lock_bh(&pch->upl);
3156 write_unlock_bh(&pch->upl);
3158 /* remove it from the ppp unit's list */
3160 list_del(&pch->clist);
3161 if (--ppp->n_channels == 0)
3162 wake_up_interruptible(&ppp->file.rwait);
3164 if (atomic_dec_and_test(&ppp->file.refcnt))
3165 ppp_destroy_interface(ppp);
3172 * Free up the resources used by a ppp channel.
3174 static void ppp_destroy_channel(struct channel *pch)
3176 put_net(pch->chan_net);
3177 pch->chan_net = NULL;
3179 atomic_dec(&channel_count);
3181 if (!pch->file.dead) {
3182 /* "can't happen" */
3183 pr_err("ppp: destroying undead channel %p !\n", pch);
3186 skb_queue_purge(&pch->file.xq);
3187 skb_queue_purge(&pch->file.rq);
3191 static void __exit ppp_cleanup(void)
3193 /* should never happen */
3194 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3195 pr_err("PPP: removing module but units remain!\n");
3196 rtnl_link_unregister(&ppp_link_ops);
3197 unregister_chrdev(PPP_MAJOR, "ppp");
3198 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3199 class_destroy(ppp_class);
3200 unregister_pernet_device(&ppp_net_ops);
3204 * Units handling. Caller must protect concurrent access
3205 * by holding all_ppp_mutex
3208 /* associate pointer with specified number */
3209 static int unit_set(struct idr *p, void *ptr, int n)
3213 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3214 if (unit == -ENOSPC)
3219 /* get new free unit number and associate pointer with it */
3220 static int unit_get(struct idr *p, void *ptr)
3222 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL);
3225 /* put unit number back to a pool */
3226 static void unit_put(struct idr *p, int n)
3231 /* get pointer associated with the number */
3232 static void *unit_find(struct idr *p, int n)
3234 return idr_find(p, n);
3237 /* Module/initialization stuff */
3239 module_init(ppp_init);
3240 module_exit(ppp_cleanup);
3242 EXPORT_SYMBOL(ppp_register_net_channel);
3243 EXPORT_SYMBOL(ppp_register_channel);
3244 EXPORT_SYMBOL(ppp_unregister_channel);
3245 EXPORT_SYMBOL(ppp_channel_index);
3246 EXPORT_SYMBOL(ppp_unit_number);
3247 EXPORT_SYMBOL(ppp_dev_name);
3248 EXPORT_SYMBOL(ppp_input);
3249 EXPORT_SYMBOL(ppp_input_error);
3250 EXPORT_SYMBOL(ppp_output_wakeup);
3251 EXPORT_SYMBOL(ppp_register_compressor);
3252 EXPORT_SYMBOL(ppp_unregister_compressor);
3253 MODULE_LICENSE("GPL");
3254 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3255 MODULE_ALIAS_RTNL_LINK("ppp");
3256 MODULE_ALIAS("devname:ppp");