2 * Generic PPP layer for Linux.
4 * Copyright 1999-2002 Paul Mackerras.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 * The generic PPP layer handles the PPP network interfaces, the
12 * /dev/ppp device, packet and VJ compression, and multilink.
13 * It talks to PPP `channels' via the interface defined in
14 * include/linux/ppp_channel.h. Channels provide the basic means for
15 * sending and receiving PPP frames on some kind of communications
18 * Part of the code in this driver was inspired by the old async-only
19 * PPP driver, written by Michael Callahan and Al Longyear, and
20 * subsequently hacked by Paul Mackerras.
22 * ==FILEVERSION 20041108==
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/kmod.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/idr.h>
31 #include <linux/netdevice.h>
32 #include <linux/poll.h>
33 #include <linux/ppp_defs.h>
34 #include <linux/filter.h>
35 #include <linux/ppp-ioctl.h>
36 #include <linux/ppp_channel.h>
37 #include <linux/ppp-comp.h>
38 #include <linux/skbuff.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/if_arp.h>
42 #include <linux/tcp.h>
43 #include <linux/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <linux/slab.h>
49 #include <linux/file.h>
50 #include <asm/unaligned.h>
51 #include <net/slhc_vj.h>
52 #include <linux/atomic.h>
54 #include <linux/nsproxy.h>
55 #include <net/net_namespace.h>
56 #include <net/netns/generic.h>
58 #define PPP_VERSION "2.4.2"
61 * Network protocols we support.
63 #define NP_IP 0 /* Internet Protocol V4 */
64 #define NP_IPV6 1 /* Internet Protocol V6 */
65 #define NP_IPX 2 /* IPX protocol */
66 #define NP_AT 3 /* Appletalk protocol */
67 #define NP_MPLS_UC 4 /* MPLS unicast */
68 #define NP_MPLS_MC 5 /* MPLS multicast */
69 #define NUM_NP 6 /* Number of NPs. */
71 #define MPHDRLEN 6 /* multilink protocol header length */
72 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
75 * An instance of /dev/ppp can be associated with either a ppp
76 * interface unit or a ppp channel. In both cases, file->private_data
77 * points to one of these.
83 struct sk_buff_head xq; /* pppd transmit queue */
84 struct sk_buff_head rq; /* receive queue for pppd */
85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
86 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
87 int hdrlen; /* space to leave for headers */
88 int index; /* interface unit / channel number */
89 int dead; /* unit/channel has been shut down */
92 #define PF_TO_X(pf, X) container_of(pf, X, file)
94 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
95 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
98 * Data structure to hold primary network stats for which
99 * we want to use 64 bit storage. Other network stats
100 * are stored in dev->stats of the ppp strucute.
102 struct ppp_link_stats {
110 * Data structure describing one ppp unit.
111 * A ppp unit corresponds to a ppp network interface device
112 * and represents a multilink bundle.
113 * It can have 0 or more ppp channels connected to it.
116 struct ppp_file file; /* stuff for read/write/poll 0 */
117 struct file *owner; /* file that owns this unit 48 */
118 struct list_head channels; /* list of attached channels 4c */
119 int n_channels; /* how many channels are attached 54 */
120 spinlock_t rlock; /* lock for receive side 58 */
121 spinlock_t wlock; /* lock for transmit side 5c */
122 int *xmit_recursion __percpu; /* xmit recursion detect */
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 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, struct sk_buff *skb);
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, int min);
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)) {
516 ppp_xmit_process(PF_TO_PPP(pf), skb);
519 skb_queue_tail(&pf->xq, skb);
520 ppp_channel_push(PF_TO_CHANNEL(pf));
530 /* No kernel lock - fine */
531 static unsigned int ppp_poll(struct file *file, poll_table *wait)
533 struct ppp_file *pf = file->private_data;
538 poll_wait(file, &pf->rwait, wait);
539 mask = POLLOUT | POLLWRNORM;
540 if (skb_peek(&pf->rq))
541 mask |= POLLIN | POLLRDNORM;
544 else if (pf->kind == INTERFACE) {
545 /* see comment in ppp_read */
546 struct ppp *ppp = PF_TO_PPP(pf);
549 if (ppp->n_channels == 0 &&
550 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
551 mask |= POLLIN | POLLRDNORM;
552 ppp_recv_unlock(ppp);
558 #ifdef CONFIG_PPP_FILTER
559 static int get_filter(void __user *arg, struct sock_filter **p)
561 struct sock_fprog uprog;
562 struct sock_filter *code = NULL;
565 if (copy_from_user(&uprog, arg, sizeof(uprog)))
573 len = uprog.len * sizeof(struct sock_filter);
574 code = memdup_user(uprog.filter, len);
576 return PTR_ERR(code);
581 #endif /* CONFIG_PPP_FILTER */
583 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
587 int err = -EFAULT, val, val2, i;
588 struct ppp_idle idle;
591 struct slcompress *vj;
592 void __user *argp = (void __user *)arg;
593 int __user *p = argp;
595 mutex_lock(&ppp_mutex);
597 pf = file->private_data;
599 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
604 if (cmd == PPPIOCDETACH) {
606 * We have to be careful here... if the file descriptor
607 * has been dup'd, we could have another process in the
608 * middle of a poll using the same file *, so we had
609 * better not free the interface data structures -
610 * instead we fail the ioctl. Even in this case, we
611 * shut down the interface if we are the owner of it.
612 * Actually, we should get rid of PPPIOCDETACH, userland
613 * (i.e. pppd) could achieve the same effect by closing
614 * this fd and reopening /dev/ppp.
617 if (pf->kind == INTERFACE) {
620 if (file == ppp->owner)
621 unregister_netdevice(ppp->dev);
624 if (atomic_long_read(&file->f_count) < 2) {
625 ppp_release(NULL, file);
628 pr_warn("PPPIOCDETACH file->f_count=%ld\n",
629 atomic_long_read(&file->f_count));
633 if (pf->kind == CHANNEL) {
635 struct ppp_channel *chan;
637 pch = PF_TO_CHANNEL(pf);
641 if (get_user(unit, p))
643 err = ppp_connect_channel(pch, unit);
647 err = ppp_disconnect_channel(pch);
651 down_read(&pch->chan_sem);
654 if (chan && chan->ops->ioctl)
655 err = chan->ops->ioctl(chan, cmd, arg);
656 up_read(&pch->chan_sem);
661 if (pf->kind != INTERFACE) {
663 pr_err("PPP: not interface or channel??\n");
671 if (get_user(val, p))
678 if (get_user(val, p))
681 cflags = ppp->flags & ~val;
682 #ifdef CONFIG_PPP_MULTILINK
683 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
686 ppp->flags = val & SC_FLAG_BITS;
688 if (cflags & SC_CCP_OPEN)
694 val = ppp->flags | ppp->xstate | ppp->rstate;
695 if (put_user(val, p))
700 case PPPIOCSCOMPRESS:
701 err = ppp_set_compress(ppp, arg);
705 if (put_user(ppp->file.index, p))
711 if (get_user(val, p))
718 if (put_user(ppp->debug, p))
724 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
725 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
726 if (copy_to_user(argp, &idle, sizeof(idle)))
732 if (get_user(val, p))
735 if ((val >> 16) != 0) {
739 vj = slhc_init(val2+1, val+1);
754 if (copy_from_user(&npi, argp, sizeof(npi)))
756 err = proto_to_npindex(npi.protocol);
760 if (cmd == PPPIOCGNPMODE) {
762 npi.mode = ppp->npmode[i];
763 if (copy_to_user(argp, &npi, sizeof(npi)))
766 ppp->npmode[i] = npi.mode;
767 /* we may be able to transmit more packets now (??) */
768 netif_wake_queue(ppp->dev);
773 #ifdef CONFIG_PPP_FILTER
776 struct sock_filter *code;
778 err = get_filter(argp, &code);
780 struct bpf_prog *pass_filter = NULL;
781 struct sock_fprog_kern fprog = {
788 err = bpf_prog_create(&pass_filter, &fprog);
791 if (ppp->pass_filter)
792 bpf_prog_destroy(ppp->pass_filter);
793 ppp->pass_filter = pass_filter;
802 struct sock_filter *code;
804 err = get_filter(argp, &code);
806 struct bpf_prog *active_filter = NULL;
807 struct sock_fprog_kern fprog = {
814 err = bpf_prog_create(&active_filter, &fprog);
817 if (ppp->active_filter)
818 bpf_prog_destroy(ppp->active_filter);
819 ppp->active_filter = active_filter;
826 #endif /* CONFIG_PPP_FILTER */
828 #ifdef CONFIG_PPP_MULTILINK
830 if (get_user(val, p))
834 ppp_recv_unlock(ppp);
837 #endif /* CONFIG_PPP_MULTILINK */
844 mutex_unlock(&ppp_mutex);
849 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
850 struct file *file, unsigned int cmd, unsigned long arg)
852 int unit, err = -EFAULT;
854 struct channel *chan;
856 int __user *p = (int __user *)arg;
860 /* Create a new ppp unit */
861 if (get_user(unit, p))
863 err = ppp_create_interface(net, file, &unit);
868 if (put_user(unit, p))
874 /* Attach to an existing ppp unit */
875 if (get_user(unit, p))
878 pn = ppp_pernet(net);
879 mutex_lock(&pn->all_ppp_mutex);
880 ppp = ppp_find_unit(pn, unit);
882 atomic_inc(&ppp->file.refcnt);
883 file->private_data = &ppp->file;
886 mutex_unlock(&pn->all_ppp_mutex);
890 if (get_user(unit, p))
893 pn = ppp_pernet(net);
894 spin_lock_bh(&pn->all_channels_lock);
895 chan = ppp_find_channel(pn, unit);
897 atomic_inc(&chan->file.refcnt);
898 file->private_data = &chan->file;
901 spin_unlock_bh(&pn->all_channels_lock);
911 static const struct file_operations ppp_device_fops = {
912 .owner = THIS_MODULE,
916 .unlocked_ioctl = ppp_ioctl,
918 .release = ppp_release,
919 .llseek = noop_llseek,
922 static __net_init int ppp_init_net(struct net *net)
924 struct ppp_net *pn = net_generic(net, ppp_net_id);
926 idr_init(&pn->units_idr);
927 mutex_init(&pn->all_ppp_mutex);
929 INIT_LIST_HEAD(&pn->all_channels);
930 INIT_LIST_HEAD(&pn->new_channels);
932 spin_lock_init(&pn->all_channels_lock);
937 static __net_exit void ppp_exit_net(struct net *net)
939 struct ppp_net *pn = net_generic(net, ppp_net_id);
940 struct net_device *dev;
941 struct net_device *aux;
947 for_each_netdev_safe(net, dev, aux) {
948 if (dev->netdev_ops == &ppp_netdev_ops)
949 unregister_netdevice_queue(dev, &list);
952 idr_for_each_entry(&pn->units_idr, ppp, id)
953 /* Skip devices already unregistered by previous loop */
954 if (!net_eq(dev_net(ppp->dev), net))
955 unregister_netdevice_queue(ppp->dev, &list);
957 unregister_netdevice_many(&list);
960 mutex_destroy(&pn->all_ppp_mutex);
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, 0);
982 if (!ifname_is_set) {
984 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret);
985 if (!__dev_get_by_name(ppp->ppp_net, ppp->dev->name))
987 unit_put(&pn->units_idr, ret);
988 ret = unit_get(&pn->units_idr, ppp, ret + 1);
994 /* Caller asked for a specific unit number. Fail with -EEXIST
995 * if unavailable. For backward compatibility, return -EEXIST
996 * too if idr allocation fails; this makes pppd retry without
997 * requesting a specific unit number.
999 if (unit_find(&pn->units_idr, unit)) {
1003 ret = unit_set(&pn->units_idr, ppp, unit);
1005 /* Rewrite error for backward compatibility */
1010 ppp->file.index = ret;
1013 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1015 mutex_unlock(&pn->all_ppp_mutex);
1017 ret = register_netdevice(ppp->dev);
1021 atomic_inc(&ppp_unit_count);
1026 mutex_lock(&pn->all_ppp_mutex);
1027 unit_put(&pn->units_idr, ppp->file.index);
1029 mutex_unlock(&pn->all_ppp_mutex);
1034 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1035 const struct ppp_config *conf)
1037 struct ppp *ppp = netdev_priv(dev);
1043 ppp->ppp_net = src_net;
1045 ppp->owner = conf->file;
1047 init_ppp_file(&ppp->file, INTERFACE);
1048 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1050 for (indx = 0; indx < NUM_NP; ++indx)
1051 ppp->npmode[indx] = NPMODE_PASS;
1052 INIT_LIST_HEAD(&ppp->channels);
1053 spin_lock_init(&ppp->rlock);
1054 spin_lock_init(&ppp->wlock);
1056 ppp->xmit_recursion = alloc_percpu(int);
1057 if (!ppp->xmit_recursion) {
1061 for_each_possible_cpu(cpu)
1062 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1064 #ifdef CONFIG_PPP_MULTILINK
1066 skb_queue_head_init(&ppp->mrq);
1067 #endif /* CONFIG_PPP_MULTILINK */
1068 #ifdef CONFIG_PPP_FILTER
1069 ppp->pass_filter = NULL;
1070 ppp->active_filter = NULL;
1071 #endif /* CONFIG_PPP_FILTER */
1073 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1077 conf->file->private_data = &ppp->file;
1081 free_percpu(ppp->xmit_recursion);
1086 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1087 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1090 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[])
1095 if (!data[IFLA_PPP_DEV_FD])
1097 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1103 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1104 struct nlattr *tb[], struct nlattr *data[])
1106 struct ppp_config conf = {
1108 .ifname_is_set = true,
1113 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1117 /* rtnl_lock is already held here, but ppp_create_interface() locks
1118 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1119 * possible deadlock due to lock order inversion, at the cost of
1120 * pushing the problem back to userspace.
1122 if (!mutex_trylock(&ppp_mutex)) {
1127 if (file->f_op != &ppp_device_fops || file->private_data) {
1134 /* Don't use device name generated by the rtnetlink layer when ifname
1135 * isn't specified. Let ppp_dev_configure() set the device name using
1136 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1137 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1139 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME]))
1140 conf.ifname_is_set = false;
1142 err = ppp_dev_configure(src_net, dev, &conf);
1145 mutex_unlock(&ppp_mutex);
1152 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1154 unregister_netdevice_queue(dev, head);
1157 static size_t ppp_nl_get_size(const struct net_device *dev)
1162 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1167 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1169 struct ppp *ppp = netdev_priv(dev);
1171 return ppp->ppp_net;
1174 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1176 .maxtype = IFLA_PPP_MAX,
1177 .policy = ppp_nl_policy,
1178 .priv_size = sizeof(struct ppp),
1180 .validate = ppp_nl_validate,
1181 .newlink = ppp_nl_newlink,
1182 .dellink = ppp_nl_dellink,
1183 .get_size = ppp_nl_get_size,
1184 .fill_info = ppp_nl_fill_info,
1185 .get_link_net = ppp_nl_get_link_net,
1188 #define PPP_MAJOR 108
1190 /* Called at boot time if ppp is compiled into the kernel,
1191 or at module load time (from init_module) if compiled as a module. */
1192 static int __init ppp_init(void)
1196 pr_info("PPP generic driver version " PPP_VERSION "\n");
1198 err = register_pernet_device(&ppp_net_ops);
1200 pr_err("failed to register PPP pernet device (%d)\n", err);
1204 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1206 pr_err("failed to register PPP device (%d)\n", err);
1210 ppp_class = class_create(THIS_MODULE, "ppp");
1211 if (IS_ERR(ppp_class)) {
1212 err = PTR_ERR(ppp_class);
1216 err = rtnl_link_register(&ppp_link_ops);
1218 pr_err("failed to register rtnetlink PPP handler\n");
1222 /* not a big deal if we fail here :-) */
1223 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1228 class_destroy(ppp_class);
1230 unregister_chrdev(PPP_MAJOR, "ppp");
1232 unregister_pernet_device(&ppp_net_ops);
1238 * Network interface unit routines.
1241 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1243 struct ppp *ppp = netdev_priv(dev);
1247 npi = ethertype_to_npindex(ntohs(skb->protocol));
1251 /* Drop, accept or reject the packet */
1252 switch (ppp->npmode[npi]) {
1256 /* it would be nice to have a way to tell the network
1257 system to queue this one up for later. */
1264 /* Put the 2-byte PPP protocol number on the front,
1265 making sure there is room for the address and control fields. */
1266 if (skb_cow_head(skb, PPP_HDRLEN))
1269 pp = skb_push(skb, 2);
1270 proto = npindex_to_proto[npi];
1271 put_unaligned_be16(proto, pp);
1273 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1274 ppp_xmit_process(ppp, skb);
1276 return NETDEV_TX_OK;
1280 ++dev->stats.tx_dropped;
1281 return NETDEV_TX_OK;
1285 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1287 struct ppp *ppp = netdev_priv(dev);
1289 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1290 struct ppp_stats stats;
1291 struct ppp_comp_stats cstats;
1296 ppp_get_stats(ppp, &stats);
1297 if (copy_to_user(addr, &stats, sizeof(stats)))
1302 case SIOCGPPPCSTATS:
1303 memset(&cstats, 0, sizeof(cstats));
1305 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1307 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1308 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1315 if (copy_to_user(addr, vers, strlen(vers) + 1))
1327 static struct rtnl_link_stats64*
1328 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1330 struct ppp *ppp = netdev_priv(dev);
1333 stats64->rx_packets = ppp->stats64.rx_packets;
1334 stats64->rx_bytes = ppp->stats64.rx_bytes;
1335 ppp_recv_unlock(ppp);
1338 stats64->tx_packets = ppp->stats64.tx_packets;
1339 stats64->tx_bytes = ppp->stats64.tx_bytes;
1340 ppp_xmit_unlock(ppp);
1342 stats64->rx_errors = dev->stats.rx_errors;
1343 stats64->tx_errors = dev->stats.tx_errors;
1344 stats64->rx_dropped = dev->stats.rx_dropped;
1345 stats64->tx_dropped = dev->stats.tx_dropped;
1346 stats64->rx_length_errors = dev->stats.rx_length_errors;
1351 static int ppp_dev_init(struct net_device *dev)
1355 netdev_lockdep_set_classes(dev);
1357 ppp = netdev_priv(dev);
1358 /* Let the netdevice take a reference on the ppp file. This ensures
1359 * that ppp_destroy_interface() won't run before the device gets
1362 atomic_inc(&ppp->file.refcnt);
1367 static void ppp_dev_uninit(struct net_device *dev)
1369 struct ppp *ppp = netdev_priv(dev);
1370 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1376 mutex_lock(&pn->all_ppp_mutex);
1377 unit_put(&pn->units_idr, ppp->file.index);
1378 mutex_unlock(&pn->all_ppp_mutex);
1383 wake_up_interruptible(&ppp->file.rwait);
1386 static void ppp_dev_priv_destructor(struct net_device *dev)
1390 ppp = netdev_priv(dev);
1391 if (atomic_dec_and_test(&ppp->file.refcnt))
1392 ppp_destroy_interface(ppp);
1395 static const struct net_device_ops ppp_netdev_ops = {
1396 .ndo_init = ppp_dev_init,
1397 .ndo_uninit = ppp_dev_uninit,
1398 .ndo_start_xmit = ppp_start_xmit,
1399 .ndo_do_ioctl = ppp_net_ioctl,
1400 .ndo_get_stats64 = ppp_get_stats64,
1403 static struct device_type ppp_type = {
1407 static void ppp_setup(struct net_device *dev)
1409 dev->netdev_ops = &ppp_netdev_ops;
1410 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1412 dev->features |= NETIF_F_LLTX;
1414 dev->hard_header_len = PPP_HDRLEN;
1417 dev->tx_queue_len = 3;
1418 dev->type = ARPHRD_PPP;
1419 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1420 dev->destructor = ppp_dev_priv_destructor;
1421 netif_keep_dst(dev);
1425 * Transmit-side routines.
1428 /* Called to do any work queued up on the transmit side that can now be done */
1429 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1432 if (!ppp->closing) {
1436 skb_queue_tail(&ppp->file.xq, skb);
1437 while (!ppp->xmit_pending &&
1438 (skb = skb_dequeue(&ppp->file.xq)))
1439 ppp_send_frame(ppp, skb);
1440 /* If there's no work left to do, tell the core net
1441 code that we can accept some more. */
1442 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1443 netif_wake_queue(ppp->dev);
1445 netif_stop_queue(ppp->dev);
1449 ppp_xmit_unlock(ppp);
1452 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1456 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1459 (*this_cpu_ptr(ppp->xmit_recursion))++;
1460 __ppp_xmit_process(ppp, skb);
1461 (*this_cpu_ptr(ppp->xmit_recursion))--;
1472 if (net_ratelimit())
1473 netdev_err(ppp->dev, "recursion detected\n");
1476 static inline struct sk_buff *
1477 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1479 struct sk_buff *new_skb;
1481 int new_skb_size = ppp->dev->mtu +
1482 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1483 int compressor_skb_size = ppp->dev->mtu +
1484 ppp->xcomp->comp_extra + PPP_HDRLEN;
1485 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1487 if (net_ratelimit())
1488 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1491 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1492 skb_reserve(new_skb,
1493 ppp->dev->hard_header_len - PPP_HDRLEN);
1495 /* compressor still expects A/C bytes in hdr */
1496 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1497 new_skb->data, skb->len + 2,
1498 compressor_skb_size);
1499 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1503 skb_pull(skb, 2); /* pull off A/C bytes */
1504 } else if (len == 0) {
1505 /* didn't compress, or CCP not up yet */
1506 consume_skb(new_skb);
1511 * MPPE requires that we do not send unencrypted
1512 * frames. The compressor will return -1 if we
1513 * should drop the frame. We cannot simply test
1514 * the compress_proto because MPPE and MPPC share
1517 if (net_ratelimit())
1518 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1520 consume_skb(new_skb);
1527 * Compress and send a frame.
1528 * The caller should have locked the xmit path,
1529 * and xmit_pending should be 0.
1532 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1534 int proto = PPP_PROTO(skb);
1535 struct sk_buff *new_skb;
1539 if (proto < 0x8000) {
1540 #ifdef CONFIG_PPP_FILTER
1541 /* check if we should pass this packet */
1542 /* the filter instructions are constructed assuming
1543 a four-byte PPP header on each packet */
1544 *skb_push(skb, 2) = 1;
1545 if (ppp->pass_filter &&
1546 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1548 netdev_printk(KERN_DEBUG, ppp->dev,
1549 "PPP: outbound frame "
1554 /* if this packet passes the active filter, record the time */
1555 if (!(ppp->active_filter &&
1556 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1557 ppp->last_xmit = jiffies;
1560 /* for data packets, record the time */
1561 ppp->last_xmit = jiffies;
1562 #endif /* CONFIG_PPP_FILTER */
1565 ++ppp->stats64.tx_packets;
1566 ppp->stats64.tx_bytes += skb->len - 2;
1570 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1572 /* try to do VJ TCP header compression */
1573 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1576 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1579 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1581 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1582 new_skb->data + 2, &cp,
1583 !(ppp->flags & SC_NO_TCP_CCID));
1584 if (cp == skb->data + 2) {
1585 /* didn't compress */
1586 consume_skb(new_skb);
1588 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1589 proto = PPP_VJC_COMP;
1590 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1592 proto = PPP_VJC_UNCOMP;
1593 cp[0] = skb->data[2];
1597 cp = skb_put(skb, len + 2);
1604 /* peek at outbound CCP frames */
1605 ppp_ccp_peek(ppp, skb, 0);
1609 /* try to do packet compression */
1610 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1611 proto != PPP_LCP && proto != PPP_CCP) {
1612 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1613 if (net_ratelimit())
1614 netdev_err(ppp->dev,
1615 "ppp: compression required but "
1616 "down - pkt dropped.\n");
1619 skb = pad_compress_skb(ppp, skb);
1625 * If we are waiting for traffic (demand dialling),
1626 * queue it up for pppd to receive.
1628 if (ppp->flags & SC_LOOP_TRAFFIC) {
1629 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1631 skb_queue_tail(&ppp->file.rq, skb);
1632 wake_up_interruptible(&ppp->file.rwait);
1636 ppp->xmit_pending = skb;
1642 ++ppp->dev->stats.tx_errors;
1646 * Try to send the frame in xmit_pending.
1647 * The caller should have the xmit path locked.
1650 ppp_push(struct ppp *ppp)
1652 struct list_head *list;
1653 struct channel *pch;
1654 struct sk_buff *skb = ppp->xmit_pending;
1659 list = &ppp->channels;
1660 if (list_empty(list)) {
1661 /* nowhere to send the packet, just drop it */
1662 ppp->xmit_pending = NULL;
1667 if ((ppp->flags & SC_MULTILINK) == 0) {
1668 /* not doing multilink: send it down the first channel */
1670 pch = list_entry(list, struct channel, clist);
1672 spin_lock_bh(&pch->downl);
1674 if (pch->chan->ops->start_xmit(pch->chan, skb))
1675 ppp->xmit_pending = NULL;
1677 /* channel got unregistered */
1679 ppp->xmit_pending = NULL;
1681 spin_unlock_bh(&pch->downl);
1685 #ifdef CONFIG_PPP_MULTILINK
1686 /* Multilink: fragment the packet over as many links
1687 as can take the packet at the moment. */
1688 if (!ppp_mp_explode(ppp, skb))
1690 #endif /* CONFIG_PPP_MULTILINK */
1692 ppp->xmit_pending = NULL;
1696 #ifdef CONFIG_PPP_MULTILINK
1697 static bool mp_protocol_compress __read_mostly = true;
1698 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR);
1699 MODULE_PARM_DESC(mp_protocol_compress,
1700 "compress protocol id in multilink fragments");
1703 * Divide a packet to be transmitted into fragments and
1704 * send them out the individual links.
1706 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1709 int i, bits, hdrlen, mtu;
1711 int navail, nfree, nzero;
1715 unsigned char *p, *q;
1716 struct list_head *list;
1717 struct channel *pch;
1718 struct sk_buff *frag;
1719 struct ppp_channel *chan;
1721 totspeed = 0; /*total bitrate of the bundle*/
1722 nfree = 0; /* # channels which have no packet already queued */
1723 navail = 0; /* total # of usable channels (not deregistered) */
1724 nzero = 0; /* number of channels with zero speed associated*/
1725 totfree = 0; /*total # of channels available and
1726 *having no queued packets before
1727 *starting the fragmentation*/
1729 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1731 list_for_each_entry(pch, &ppp->channels, clist) {
1735 pch->speed = pch->chan->speed;
1740 if (skb_queue_empty(&pch->file.xq) ||
1742 if (pch->speed == 0)
1745 totspeed += pch->speed;
1751 if (!pch->had_frag && i < ppp->nxchan)
1757 * Don't start sending this packet unless at least half of
1758 * the channels are free. This gives much better TCP
1759 * performance if we have a lot of channels.
1761 if (nfree == 0 || nfree < navail / 2)
1762 return 0; /* can't take now, leave it in xmit_pending */
1764 /* Do protocol field compression */
1767 if (*p == 0 && mp_protocol_compress) {
1773 nbigger = len % nfree;
1775 /* skip to the channel after the one we last used
1776 and start at that one */
1777 list = &ppp->channels;
1778 for (i = 0; i < ppp->nxchan; ++i) {
1780 if (list == &ppp->channels) {
1786 /* create a fragment for each channel */
1790 if (list == &ppp->channels) {
1794 pch = list_entry(list, struct channel, clist);
1800 * Skip this channel if it has a fragment pending already and
1801 * we haven't given a fragment to all of the free channels.
1803 if (pch->avail == 1) {
1810 /* check the channel's mtu and whether it is still attached. */
1811 spin_lock_bh(&pch->downl);
1812 if (pch->chan == NULL) {
1813 /* can't use this channel, it's being deregistered */
1814 if (pch->speed == 0)
1817 totspeed -= pch->speed;
1819 spin_unlock_bh(&pch->downl);
1830 *if the channel speed is not set divide
1831 *the packet evenly among the free channels;
1832 *otherwise divide it according to the speed
1833 *of the channel we are going to transmit on
1837 if (pch->speed == 0) {
1844 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1845 ((totspeed*totfree)/pch->speed)) - hdrlen;
1847 flen += ((totfree - nzero)*pch->speed)/totspeed;
1848 nbigger -= ((totfree - nzero)*pch->speed)/
1856 *check if we are on the last channel or
1857 *we exceded the length of the data to
1860 if ((nfree <= 0) || (flen > len))
1863 *it is not worth to tx on slow channels:
1864 *in that case from the resulting flen according to the
1865 *above formula will be equal or less than zero.
1866 *Skip the channel in this case
1870 spin_unlock_bh(&pch->downl);
1875 * hdrlen includes the 2-byte PPP protocol field, but the
1876 * MTU counts only the payload excluding the protocol field.
1877 * (RFC1661 Section 2)
1879 mtu = pch->chan->mtu - (hdrlen - 2);
1886 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1889 q = skb_put(frag, flen + hdrlen);
1891 /* make the MP header */
1892 put_unaligned_be16(PPP_MP, q);
1893 if (ppp->flags & SC_MP_XSHORTSEQ) {
1894 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1898 q[3] = ppp->nxseq >> 16;
1899 q[4] = ppp->nxseq >> 8;
1903 memcpy(q + hdrlen, p, flen);
1905 /* try to send it down the channel */
1907 if (!skb_queue_empty(&pch->file.xq) ||
1908 !chan->ops->start_xmit(chan, frag))
1909 skb_queue_tail(&pch->file.xq, frag);
1915 spin_unlock_bh(&pch->downl);
1922 spin_unlock_bh(&pch->downl);
1924 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1925 ++ppp->dev->stats.tx_errors;
1927 return 1; /* abandon the frame */
1929 #endif /* CONFIG_PPP_MULTILINK */
1931 /* Try to send data out on a channel */
1932 static void __ppp_channel_push(struct channel *pch)
1934 struct sk_buff *skb;
1937 spin_lock_bh(&pch->downl);
1939 while (!skb_queue_empty(&pch->file.xq)) {
1940 skb = skb_dequeue(&pch->file.xq);
1941 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1942 /* put the packet back and try again later */
1943 skb_queue_head(&pch->file.xq, skb);
1948 /* channel got deregistered */
1949 skb_queue_purge(&pch->file.xq);
1951 spin_unlock_bh(&pch->downl);
1952 /* see if there is anything from the attached unit to be sent */
1953 if (skb_queue_empty(&pch->file.xq)) {
1956 __ppp_xmit_process(ppp, NULL);
1960 static void ppp_channel_push(struct channel *pch)
1962 read_lock_bh(&pch->upl);
1964 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
1965 __ppp_channel_push(pch);
1966 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
1968 __ppp_channel_push(pch);
1970 read_unlock_bh(&pch->upl);
1974 * Receive-side routines.
1977 struct ppp_mp_skb_parm {
1981 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1984 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1988 ppp_receive_frame(ppp, skb, pch);
1991 ppp_recv_unlock(ppp);
1995 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1997 struct channel *pch = chan->ppp;
2005 read_lock_bh(&pch->upl);
2006 if (!pskb_may_pull(skb, 2)) {
2009 ++pch->ppp->dev->stats.rx_length_errors;
2010 ppp_receive_error(pch->ppp);
2015 proto = PPP_PROTO(skb);
2016 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2017 /* put it on the channel queue */
2018 skb_queue_tail(&pch->file.rq, skb);
2019 /* drop old frames if queue too long */
2020 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2021 (skb = skb_dequeue(&pch->file.rq)))
2023 wake_up_interruptible(&pch->file.rwait);
2025 ppp_do_recv(pch->ppp, skb, pch);
2029 read_unlock_bh(&pch->upl);
2032 /* Put a 0-length skb in the receive queue as an error indication */
2034 ppp_input_error(struct ppp_channel *chan, int code)
2036 struct channel *pch = chan->ppp;
2037 struct sk_buff *skb;
2042 read_lock_bh(&pch->upl);
2044 skb = alloc_skb(0, GFP_ATOMIC);
2046 skb->len = 0; /* probably unnecessary */
2048 ppp_do_recv(pch->ppp, skb, pch);
2051 read_unlock_bh(&pch->upl);
2055 * We come in here to process a received frame.
2056 * The receive side of the ppp unit is locked.
2059 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2061 /* note: a 0-length skb is used as an error indication */
2063 skb_checksum_complete_unset(skb);
2064 #ifdef CONFIG_PPP_MULTILINK
2065 /* XXX do channel-level decompression here */
2066 if (PPP_PROTO(skb) == PPP_MP)
2067 ppp_receive_mp_frame(ppp, skb, pch);
2069 #endif /* CONFIG_PPP_MULTILINK */
2070 ppp_receive_nonmp_frame(ppp, skb);
2073 ppp_receive_error(ppp);
2078 ppp_receive_error(struct ppp *ppp)
2080 ++ppp->dev->stats.rx_errors;
2086 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2089 int proto, len, npi;
2092 * Decompress the frame, if compressed.
2093 * Note that some decompressors need to see uncompressed frames
2094 * that come in as well as compressed frames.
2096 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2097 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2098 skb = ppp_decompress_frame(ppp, skb);
2100 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2103 proto = PPP_PROTO(skb);
2106 /* decompress VJ compressed packets */
2107 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2110 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2111 /* copy to a new sk_buff with more tailroom */
2112 ns = dev_alloc_skb(skb->len + 128);
2114 netdev_err(ppp->dev, "PPP: no memory "
2119 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2124 skb->ip_summed = CHECKSUM_NONE;
2126 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2128 netdev_printk(KERN_DEBUG, ppp->dev,
2129 "PPP: VJ decompression error\n");
2134 skb_put(skb, len - skb->len);
2135 else if (len < skb->len)
2140 case PPP_VJC_UNCOMP:
2141 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2144 /* Until we fix the decompressor need to make sure
2145 * data portion is linear.
2147 if (!pskb_may_pull(skb, skb->len))
2150 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2151 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2158 ppp_ccp_peek(ppp, skb, 1);
2162 ++ppp->stats64.rx_packets;
2163 ppp->stats64.rx_bytes += skb->len - 2;
2165 npi = proto_to_npindex(proto);
2167 /* control or unknown frame - pass it to pppd */
2168 skb_queue_tail(&ppp->file.rq, skb);
2169 /* limit queue length by dropping old frames */
2170 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2171 (skb = skb_dequeue(&ppp->file.rq)))
2173 /* wake up any process polling or blocking on read */
2174 wake_up_interruptible(&ppp->file.rwait);
2177 /* network protocol frame - give it to the kernel */
2179 #ifdef CONFIG_PPP_FILTER
2180 /* check if the packet passes the pass and active filters */
2181 /* the filter instructions are constructed assuming
2182 a four-byte PPP header on each packet */
2183 if (ppp->pass_filter || ppp->active_filter) {
2184 if (skb_unclone(skb, GFP_ATOMIC))
2187 *skb_push(skb, 2) = 0;
2188 if (ppp->pass_filter &&
2189 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2191 netdev_printk(KERN_DEBUG, ppp->dev,
2192 "PPP: inbound frame "
2197 if (!(ppp->active_filter &&
2198 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2199 ppp->last_recv = jiffies;
2202 #endif /* CONFIG_PPP_FILTER */
2203 ppp->last_recv = jiffies;
2205 if ((ppp->dev->flags & IFF_UP) == 0 ||
2206 ppp->npmode[npi] != NPMODE_PASS) {
2209 /* chop off protocol */
2210 skb_pull_rcsum(skb, 2);
2211 skb->dev = ppp->dev;
2212 skb->protocol = htons(npindex_to_ethertype[npi]);
2213 skb_reset_mac_header(skb);
2214 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2215 dev_net(ppp->dev)));
2223 ppp_receive_error(ppp);
2226 static struct sk_buff *
2227 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2229 int proto = PPP_PROTO(skb);
2233 /* Until we fix all the decompressor's need to make sure
2234 * data portion is linear.
2236 if (!pskb_may_pull(skb, skb->len))
2239 if (proto == PPP_COMP) {
2242 switch(ppp->rcomp->compress_proto) {
2244 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2247 obuff_size = ppp->mru + PPP_HDRLEN;
2251 ns = dev_alloc_skb(obuff_size);
2253 netdev_err(ppp->dev, "ppp_decompress_frame: "
2257 /* the decompressor still expects the A/C bytes in the hdr */
2258 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2259 skb->len + 2, ns->data, obuff_size);
2261 /* Pass the compressed frame to pppd as an
2262 error indication. */
2263 if (len == DECOMP_FATALERROR)
2264 ppp->rstate |= SC_DC_FERROR;
2272 skb_pull(skb, 2); /* pull off the A/C bytes */
2275 /* Uncompressed frame - pass to decompressor so it
2276 can update its dictionary if necessary. */
2277 if (ppp->rcomp->incomp)
2278 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2285 ppp->rstate |= SC_DC_ERROR;
2286 ppp_receive_error(ppp);
2290 #ifdef CONFIG_PPP_MULTILINK
2292 * Receive a multilink frame.
2293 * We put it on the reconstruction queue and then pull off
2294 * as many completed frames as we can.
2297 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2301 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2303 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2304 goto err; /* no good, throw it away */
2306 /* Decode sequence number and begin/end bits */
2307 if (ppp->flags & SC_MP_SHORTSEQ) {
2308 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2311 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2314 PPP_MP_CB(skb)->BEbits = skb->data[2];
2315 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2318 * Do protocol ID decompression on the first fragment of each packet.
2320 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2321 *skb_push(skb, 1) = 0;
2324 * Expand sequence number to 32 bits, making it as close
2325 * as possible to ppp->minseq.
2327 seq |= ppp->minseq & ~mask;
2328 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2330 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2331 seq -= mask + 1; /* should never happen */
2332 PPP_MP_CB(skb)->sequence = seq;
2336 * If this packet comes before the next one we were expecting,
2339 if (seq_before(seq, ppp->nextseq)) {
2341 ++ppp->dev->stats.rx_dropped;
2342 ppp_receive_error(ppp);
2347 * Reevaluate minseq, the minimum over all channels of the
2348 * last sequence number received on each channel. Because of
2349 * the increasing sequence number rule, we know that any fragment
2350 * before `minseq' which hasn't arrived is never going to arrive.
2351 * The list of channels can't change because we have the receive
2352 * side of the ppp unit locked.
2354 list_for_each_entry(ch, &ppp->channels, clist) {
2355 if (seq_before(ch->lastseq, seq))
2358 if (seq_before(ppp->minseq, seq))
2361 /* Put the fragment on the reconstruction queue */
2362 ppp_mp_insert(ppp, skb);
2364 /* If the queue is getting long, don't wait any longer for packets
2365 before the start of the queue. */
2366 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2367 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2368 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2369 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2372 /* Pull completed packets off the queue and receive them. */
2373 while ((skb = ppp_mp_reconstruct(ppp))) {
2374 if (pskb_may_pull(skb, 2))
2375 ppp_receive_nonmp_frame(ppp, skb);
2377 ++ppp->dev->stats.rx_length_errors;
2379 ppp_receive_error(ppp);
2387 ppp_receive_error(ppp);
2391 * Insert a fragment on the MP reconstruction queue.
2392 * The queue is ordered by increasing sequence number.
2395 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2398 struct sk_buff_head *list = &ppp->mrq;
2399 u32 seq = PPP_MP_CB(skb)->sequence;
2401 /* N.B. we don't need to lock the list lock because we have the
2402 ppp unit receive-side lock. */
2403 skb_queue_walk(list, p) {
2404 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2407 __skb_queue_before(list, p, skb);
2411 * Reconstruct a packet from the MP fragment queue.
2412 * We go through increasing sequence numbers until we find a
2413 * complete packet, or we get to the sequence number for a fragment
2414 * which hasn't arrived but might still do so.
2416 static struct sk_buff *
2417 ppp_mp_reconstruct(struct ppp *ppp)
2419 u32 seq = ppp->nextseq;
2420 u32 minseq = ppp->minseq;
2421 struct sk_buff_head *list = &ppp->mrq;
2422 struct sk_buff *p, *tmp;
2423 struct sk_buff *head, *tail;
2424 struct sk_buff *skb = NULL;
2425 int lost = 0, len = 0;
2427 if (ppp->mrru == 0) /* do nothing until mrru is set */
2431 skb_queue_walk_safe(list, p, tmp) {
2433 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2434 /* this can't happen, anyway ignore the skb */
2435 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2437 PPP_MP_CB(p)->sequence, seq);
2438 __skb_unlink(p, list);
2442 if (PPP_MP_CB(p)->sequence != seq) {
2444 /* Fragment `seq' is missing. If it is after
2445 minseq, it might arrive later, so stop here. */
2446 if (seq_after(seq, minseq))
2448 /* Fragment `seq' is lost, keep going. */
2451 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2452 minseq + 1: PPP_MP_CB(p)->sequence;
2455 netdev_printk(KERN_DEBUG, ppp->dev,
2456 "lost frag %u..%u\n",
2463 * At this point we know that all the fragments from
2464 * ppp->nextseq to seq are either present or lost.
2465 * Also, there are no complete packets in the queue
2466 * that have no missing fragments and end before this
2470 /* B bit set indicates this fragment starts a packet */
2471 if (PPP_MP_CB(p)->BEbits & B) {
2479 /* Got a complete packet yet? */
2480 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2481 (PPP_MP_CB(head)->BEbits & B)) {
2482 if (len > ppp->mrru + 2) {
2483 ++ppp->dev->stats.rx_length_errors;
2484 netdev_printk(KERN_DEBUG, ppp->dev,
2485 "PPP: reconstructed packet"
2486 " is too long (%d)\n", len);
2491 ppp->nextseq = seq + 1;
2495 * If this is the ending fragment of a packet,
2496 * and we haven't found a complete valid packet yet,
2497 * we can discard up to and including this fragment.
2499 if (PPP_MP_CB(p)->BEbits & E) {
2500 struct sk_buff *tmp2;
2502 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2504 netdev_printk(KERN_DEBUG, ppp->dev,
2505 "discarding frag %u\n",
2506 PPP_MP_CB(p)->sequence);
2507 __skb_unlink(p, list);
2510 head = skb_peek(list);
2517 /* If we have a complete packet, copy it all into one skb. */
2519 /* If we have discarded any fragments,
2520 signal a receive error. */
2521 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2522 skb_queue_walk_safe(list, p, tmp) {
2526 netdev_printk(KERN_DEBUG, ppp->dev,
2527 "discarding frag %u\n",
2528 PPP_MP_CB(p)->sequence);
2529 __skb_unlink(p, list);
2534 netdev_printk(KERN_DEBUG, ppp->dev,
2535 " missed pkts %u..%u\n",
2537 PPP_MP_CB(head)->sequence-1);
2538 ++ppp->dev->stats.rx_dropped;
2539 ppp_receive_error(ppp);
2544 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2545 p = skb_queue_next(list, head);
2546 __skb_unlink(skb, list);
2547 skb_queue_walk_from_safe(list, p, tmp) {
2548 __skb_unlink(p, list);
2554 skb->data_len += p->len;
2555 skb->truesize += p->truesize;
2561 __skb_unlink(skb, list);
2564 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2569 #endif /* CONFIG_PPP_MULTILINK */
2572 * Channel interface.
2575 /* Create a new, unattached ppp channel. */
2576 int ppp_register_channel(struct ppp_channel *chan)
2578 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2581 /* Create a new, unattached ppp channel for specified net. */
2582 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2584 struct channel *pch;
2587 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2591 pn = ppp_pernet(net);
2595 pch->chan_net = get_net(net);
2597 init_ppp_file(&pch->file, CHANNEL);
2598 pch->file.hdrlen = chan->hdrlen;
2599 #ifdef CONFIG_PPP_MULTILINK
2601 #endif /* CONFIG_PPP_MULTILINK */
2602 init_rwsem(&pch->chan_sem);
2603 spin_lock_init(&pch->downl);
2604 rwlock_init(&pch->upl);
2606 spin_lock_bh(&pn->all_channels_lock);
2607 pch->file.index = ++pn->last_channel_index;
2608 list_add(&pch->list, &pn->new_channels);
2609 atomic_inc(&channel_count);
2610 spin_unlock_bh(&pn->all_channels_lock);
2616 * Return the index of a channel.
2618 int ppp_channel_index(struct ppp_channel *chan)
2620 struct channel *pch = chan->ppp;
2623 return pch->file.index;
2628 * Return the PPP unit number to which a channel is connected.
2630 int ppp_unit_number(struct ppp_channel *chan)
2632 struct channel *pch = chan->ppp;
2636 read_lock_bh(&pch->upl);
2638 unit = pch->ppp->file.index;
2639 read_unlock_bh(&pch->upl);
2645 * Return the PPP device interface name of a channel.
2647 char *ppp_dev_name(struct ppp_channel *chan)
2649 struct channel *pch = chan->ppp;
2653 read_lock_bh(&pch->upl);
2654 if (pch->ppp && pch->ppp->dev)
2655 name = pch->ppp->dev->name;
2656 read_unlock_bh(&pch->upl);
2663 * Disconnect a channel from the generic layer.
2664 * This must be called in process context.
2667 ppp_unregister_channel(struct ppp_channel *chan)
2669 struct channel *pch = chan->ppp;
2673 return; /* should never happen */
2678 * This ensures that we have returned from any calls into the
2679 * the channel's start_xmit or ioctl routine before we proceed.
2681 down_write(&pch->chan_sem);
2682 spin_lock_bh(&pch->downl);
2684 spin_unlock_bh(&pch->downl);
2685 up_write(&pch->chan_sem);
2686 ppp_disconnect_channel(pch);
2688 pn = ppp_pernet(pch->chan_net);
2689 spin_lock_bh(&pn->all_channels_lock);
2690 list_del(&pch->list);
2691 spin_unlock_bh(&pn->all_channels_lock);
2694 wake_up_interruptible(&pch->file.rwait);
2695 if (atomic_dec_and_test(&pch->file.refcnt))
2696 ppp_destroy_channel(pch);
2700 * Callback from a channel when it can accept more to transmit.
2701 * This should be called at BH/softirq level, not interrupt level.
2704 ppp_output_wakeup(struct ppp_channel *chan)
2706 struct channel *pch = chan->ppp;
2710 ppp_channel_push(pch);
2714 * Compression control.
2717 /* Process the PPPIOCSCOMPRESS ioctl. */
2719 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2722 struct compressor *cp, *ocomp;
2723 struct ppp_option_data data;
2724 void *state, *ostate;
2725 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2728 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2730 if (data.length > CCP_MAX_OPTION_LENGTH)
2732 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2736 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2739 cp = try_then_request_module(
2740 find_compressor(ccp_option[0]),
2741 "ppp-compress-%d", ccp_option[0]);
2746 if (data.transmit) {
2747 state = cp->comp_alloc(ccp_option, data.length);
2750 ppp->xstate &= ~SC_COMP_RUN;
2752 ostate = ppp->xc_state;
2754 ppp->xc_state = state;
2755 ppp_xmit_unlock(ppp);
2757 ocomp->comp_free(ostate);
2758 module_put(ocomp->owner);
2762 module_put(cp->owner);
2765 state = cp->decomp_alloc(ccp_option, data.length);
2768 ppp->rstate &= ~SC_DECOMP_RUN;
2770 ostate = ppp->rc_state;
2772 ppp->rc_state = state;
2773 ppp_recv_unlock(ppp);
2775 ocomp->decomp_free(ostate);
2776 module_put(ocomp->owner);
2780 module_put(cp->owner);
2788 * Look at a CCP packet and update our state accordingly.
2789 * We assume the caller has the xmit or recv path locked.
2792 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2797 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2798 return; /* no header */
2801 switch (CCP_CODE(dp)) {
2804 /* A ConfReq starts negotiation of compression
2805 * in one direction of transmission,
2806 * and hence brings it down...but which way?
2809 * A ConfReq indicates what the sender would like to receive
2812 /* He is proposing what I should send */
2813 ppp->xstate &= ~SC_COMP_RUN;
2815 /* I am proposing to what he should send */
2816 ppp->rstate &= ~SC_DECOMP_RUN;
2823 * CCP is going down, both directions of transmission
2825 ppp->rstate &= ~SC_DECOMP_RUN;
2826 ppp->xstate &= ~SC_COMP_RUN;
2830 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2832 len = CCP_LENGTH(dp);
2833 if (!pskb_may_pull(skb, len + 2))
2834 return; /* too short */
2837 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2840 /* we will start receiving compressed packets */
2843 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2844 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2845 ppp->rstate |= SC_DECOMP_RUN;
2846 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2849 /* we will soon start sending compressed packets */
2852 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2853 ppp->file.index, 0, ppp->debug))
2854 ppp->xstate |= SC_COMP_RUN;
2859 /* reset the [de]compressor */
2860 if ((ppp->flags & SC_CCP_UP) == 0)
2863 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2864 ppp->rcomp->decomp_reset(ppp->rc_state);
2865 ppp->rstate &= ~SC_DC_ERROR;
2868 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2869 ppp->xcomp->comp_reset(ppp->xc_state);
2875 /* Free up compression resources. */
2877 ppp_ccp_closed(struct ppp *ppp)
2879 void *xstate, *rstate;
2880 struct compressor *xcomp, *rcomp;
2883 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2886 xstate = ppp->xc_state;
2887 ppp->xc_state = NULL;
2890 rstate = ppp->rc_state;
2891 ppp->rc_state = NULL;
2895 xcomp->comp_free(xstate);
2896 module_put(xcomp->owner);
2899 rcomp->decomp_free(rstate);
2900 module_put(rcomp->owner);
2904 /* List of compressors. */
2905 static LIST_HEAD(compressor_list);
2906 static DEFINE_SPINLOCK(compressor_list_lock);
2908 struct compressor_entry {
2909 struct list_head list;
2910 struct compressor *comp;
2913 static struct compressor_entry *
2914 find_comp_entry(int proto)
2916 struct compressor_entry *ce;
2918 list_for_each_entry(ce, &compressor_list, list) {
2919 if (ce->comp->compress_proto == proto)
2925 /* Register a compressor */
2927 ppp_register_compressor(struct compressor *cp)
2929 struct compressor_entry *ce;
2931 spin_lock(&compressor_list_lock);
2933 if (find_comp_entry(cp->compress_proto))
2936 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2941 list_add(&ce->list, &compressor_list);
2943 spin_unlock(&compressor_list_lock);
2947 /* Unregister a compressor */
2949 ppp_unregister_compressor(struct compressor *cp)
2951 struct compressor_entry *ce;
2953 spin_lock(&compressor_list_lock);
2954 ce = find_comp_entry(cp->compress_proto);
2955 if (ce && ce->comp == cp) {
2956 list_del(&ce->list);
2959 spin_unlock(&compressor_list_lock);
2962 /* Find a compressor. */
2963 static struct compressor *
2964 find_compressor(int type)
2966 struct compressor_entry *ce;
2967 struct compressor *cp = NULL;
2969 spin_lock(&compressor_list_lock);
2970 ce = find_comp_entry(type);
2973 if (!try_module_get(cp->owner))
2976 spin_unlock(&compressor_list_lock);
2981 * Miscelleneous stuff.
2985 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2987 struct slcompress *vj = ppp->vj;
2989 memset(st, 0, sizeof(*st));
2990 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2991 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2992 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2993 st->p.ppp_opackets = ppp->stats64.tx_packets;
2994 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2995 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2998 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2999 st->vj.vjs_compressed = vj->sls_o_compressed;
3000 st->vj.vjs_searches = vj->sls_o_searches;
3001 st->vj.vjs_misses = vj->sls_o_misses;
3002 st->vj.vjs_errorin = vj->sls_i_error;
3003 st->vj.vjs_tossed = vj->sls_i_tossed;
3004 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
3005 st->vj.vjs_compressedin = vj->sls_i_compressed;
3009 * Stuff for handling the lists of ppp units and channels
3010 * and for initialization.
3014 * Create a new ppp interface unit. Fails if it can't allocate memory
3015 * or if there is already a unit with the requested number.
3016 * unit == -1 means allocate a new number.
3018 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3020 struct ppp_config conf = {
3023 .ifname_is_set = false,
3025 struct net_device *dev;
3029 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3034 dev_net_set(dev, net);
3035 dev->rtnl_link_ops = &ppp_link_ops;
3039 err = ppp_dev_configure(net, dev, &conf);
3042 ppp = netdev_priv(dev);
3043 *unit = ppp->file.index;
3057 * Initialize a ppp_file structure.
3060 init_ppp_file(struct ppp_file *pf, int kind)
3063 skb_queue_head_init(&pf->xq);
3064 skb_queue_head_init(&pf->rq);
3065 atomic_set(&pf->refcnt, 1);
3066 init_waitqueue_head(&pf->rwait);
3070 * Free the memory used by a ppp unit. This is only called once
3071 * there are no channels connected to the unit and no file structs
3072 * that reference the unit.
3074 static void ppp_destroy_interface(struct ppp *ppp)
3076 atomic_dec(&ppp_unit_count);
3078 if (!ppp->file.dead || ppp->n_channels) {
3079 /* "can't happen" */
3080 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3081 "but dead=%d n_channels=%d !\n",
3082 ppp, ppp->file.dead, ppp->n_channels);
3086 ppp_ccp_closed(ppp);
3091 skb_queue_purge(&ppp->file.xq);
3092 skb_queue_purge(&ppp->file.rq);
3093 #ifdef CONFIG_PPP_MULTILINK
3094 skb_queue_purge(&ppp->mrq);
3095 #endif /* CONFIG_PPP_MULTILINK */
3096 #ifdef CONFIG_PPP_FILTER
3097 if (ppp->pass_filter) {
3098 bpf_prog_destroy(ppp->pass_filter);
3099 ppp->pass_filter = NULL;
3102 if (ppp->active_filter) {
3103 bpf_prog_destroy(ppp->active_filter);
3104 ppp->active_filter = NULL;
3106 #endif /* CONFIG_PPP_FILTER */
3108 kfree_skb(ppp->xmit_pending);
3109 free_percpu(ppp->xmit_recursion);
3111 free_netdev(ppp->dev);
3115 * Locate an existing ppp unit.
3116 * The caller should have locked the all_ppp_mutex.
3119 ppp_find_unit(struct ppp_net *pn, int unit)
3121 return unit_find(&pn->units_idr, unit);
3125 * Locate an existing ppp channel.
3126 * The caller should have locked the all_channels_lock.
3127 * First we look in the new_channels list, then in the
3128 * all_channels list. If found in the new_channels list,
3129 * we move it to the all_channels list. This is for speed
3130 * when we have a lot of channels in use.
3132 static struct channel *
3133 ppp_find_channel(struct ppp_net *pn, int unit)
3135 struct channel *pch;
3137 list_for_each_entry(pch, &pn->new_channels, list) {
3138 if (pch->file.index == unit) {
3139 list_move(&pch->list, &pn->all_channels);
3144 list_for_each_entry(pch, &pn->all_channels, list) {
3145 if (pch->file.index == unit)
3153 * Connect a PPP channel to a PPP interface unit.
3156 ppp_connect_channel(struct channel *pch, int unit)
3163 pn = ppp_pernet(pch->chan_net);
3165 mutex_lock(&pn->all_ppp_mutex);
3166 ppp = ppp_find_unit(pn, unit);
3169 write_lock_bh(&pch->upl);
3175 spin_lock_bh(&pch->downl);
3177 /* Don't connect unregistered channels */
3178 spin_unlock_bh(&pch->downl);
3183 spin_unlock_bh(&pch->downl);
3184 if (pch->file.hdrlen > ppp->file.hdrlen)
3185 ppp->file.hdrlen = pch->file.hdrlen;
3186 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3187 if (hdrlen > ppp->dev->hard_header_len)
3188 ppp->dev->hard_header_len = hdrlen;
3189 list_add_tail(&pch->clist, &ppp->channels);
3192 atomic_inc(&ppp->file.refcnt);
3197 write_unlock_bh(&pch->upl);
3199 mutex_unlock(&pn->all_ppp_mutex);
3204 * Disconnect a channel from its ppp unit.
3207 ppp_disconnect_channel(struct channel *pch)
3212 write_lock_bh(&pch->upl);
3215 write_unlock_bh(&pch->upl);
3217 /* remove it from the ppp unit's list */
3219 list_del(&pch->clist);
3220 if (--ppp->n_channels == 0)
3221 wake_up_interruptible(&ppp->file.rwait);
3223 if (atomic_dec_and_test(&ppp->file.refcnt))
3224 ppp_destroy_interface(ppp);
3231 * Free up the resources used by a ppp channel.
3233 static void ppp_destroy_channel(struct channel *pch)
3235 put_net(pch->chan_net);
3236 pch->chan_net = NULL;
3238 atomic_dec(&channel_count);
3240 if (!pch->file.dead) {
3241 /* "can't happen" */
3242 pr_err("ppp: destroying undead channel %p !\n", pch);
3245 skb_queue_purge(&pch->file.xq);
3246 skb_queue_purge(&pch->file.rq);
3250 static void __exit ppp_cleanup(void)
3252 /* should never happen */
3253 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3254 pr_err("PPP: removing module but units remain!\n");
3255 rtnl_link_unregister(&ppp_link_ops);
3256 unregister_chrdev(PPP_MAJOR, "ppp");
3257 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3258 class_destroy(ppp_class);
3259 unregister_pernet_device(&ppp_net_ops);
3263 * Units handling. Caller must protect concurrent access
3264 * by holding all_ppp_mutex
3267 /* associate pointer with specified number */
3268 static int unit_set(struct idr *p, void *ptr, int n)
3272 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3273 if (unit == -ENOSPC)
3278 /* get new free unit number and associate pointer with it */
3279 static int unit_get(struct idr *p, void *ptr, int min)
3281 return idr_alloc(p, ptr, min, 0, GFP_KERNEL);
3284 /* put unit number back to a pool */
3285 static void unit_put(struct idr *p, int n)
3290 /* get pointer associated with the number */
3291 static void *unit_find(struct idr *p, int n)
3293 return idr_find(p, n);
3296 /* Module/initialization stuff */
3298 module_init(ppp_init);
3299 module_exit(ppp_cleanup);
3301 EXPORT_SYMBOL(ppp_register_net_channel);
3302 EXPORT_SYMBOL(ppp_register_channel);
3303 EXPORT_SYMBOL(ppp_unregister_channel);
3304 EXPORT_SYMBOL(ppp_channel_index);
3305 EXPORT_SYMBOL(ppp_unit_number);
3306 EXPORT_SYMBOL(ppp_dev_name);
3307 EXPORT_SYMBOL(ppp_input);
3308 EXPORT_SYMBOL(ppp_input_error);
3309 EXPORT_SYMBOL(ppp_output_wakeup);
3310 EXPORT_SYMBOL(ppp_register_compressor);
3311 EXPORT_SYMBOL(ppp_unregister_compressor);
3312 MODULE_LICENSE("GPL");
3313 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3314 MODULE_ALIAS_RTNL_LINK("ppp");
3315 MODULE_ALIAS("devname:ppp");