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>
54 #include <linux/refcount.h>
56 #include <linux/nsproxy.h>
57 #include <net/net_namespace.h>
58 #include <net/netns/generic.h>
60 #define PPP_VERSION "2.4.2"
63 * Network protocols we support.
65 #define NP_IP 0 /* Internet Protocol V4 */
66 #define NP_IPV6 1 /* Internet Protocol V6 */
67 #define NP_IPX 2 /* IPX protocol */
68 #define NP_AT 3 /* Appletalk protocol */
69 #define NP_MPLS_UC 4 /* MPLS unicast */
70 #define NP_MPLS_MC 5 /* MPLS multicast */
71 #define NUM_NP 6 /* Number of NPs. */
73 #define MPHDRLEN 6 /* multilink protocol header length */
74 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
76 #define PPP_PROTO_LEN 2
79 * An instance of /dev/ppp can be associated with either a ppp
80 * interface unit or a ppp channel. In both cases, file->private_data
81 * points to one of these.
87 struct sk_buff_head xq; /* pppd transmit queue */
88 struct sk_buff_head rq; /* receive queue for pppd */
89 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
90 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */
91 int hdrlen; /* space to leave for headers */
92 int index; /* interface unit / channel number */
93 int dead; /* unit/channel has been shut down */
96 #define PF_TO_X(pf, X) container_of(pf, X, file)
98 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
99 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
102 * Data structure to hold primary network stats for which
103 * we want to use 64 bit storage. Other network stats
104 * are stored in dev->stats of the ppp strucute.
106 struct ppp_link_stats {
114 * Data structure describing one ppp unit.
115 * A ppp unit corresponds to a ppp network interface device
116 * and represents a multilink bundle.
117 * It can have 0 or more ppp channels connected to it.
120 struct ppp_file file; /* stuff for read/write/poll 0 */
121 struct file *owner; /* file that owns this unit 48 */
122 struct list_head channels; /* list of attached channels 4c */
123 int n_channels; /* how many channels are attached 54 */
124 spinlock_t rlock; /* lock for receive side 58 */
125 spinlock_t wlock; /* lock for transmit side 5c */
126 int __percpu *xmit_recursion; /* xmit recursion detect */
127 int mru; /* max receive unit 60 */
128 unsigned int flags; /* control bits 64 */
129 unsigned int xstate; /* transmit state bits 68 */
130 unsigned int rstate; /* receive state bits 6c */
131 int debug; /* debug flags 70 */
132 struct slcompress *vj; /* state for VJ header compression */
133 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
134 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
135 struct compressor *xcomp; /* transmit packet compressor 8c */
136 void *xc_state; /* its internal state 90 */
137 struct compressor *rcomp; /* receive decompressor 94 */
138 void *rc_state; /* its internal state 98 */
139 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
140 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
141 struct net_device *dev; /* network interface device a4 */
142 int closing; /* is device closing down? a8 */
143 #ifdef CONFIG_PPP_MULTILINK
144 int nxchan; /* next channel to send something on */
145 u32 nxseq; /* next sequence number to send */
146 int mrru; /* MP: max reconst. receive unit */
147 u32 nextseq; /* MP: seq no of next packet */
148 u32 minseq; /* MP: min of most recent seqnos */
149 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
150 #endif /* CONFIG_PPP_MULTILINK */
151 #ifdef CONFIG_PPP_FILTER
152 struct bpf_prog *pass_filter; /* filter for packets to pass */
153 struct bpf_prog *active_filter; /* filter for pkts to reset idle */
154 #endif /* CONFIG_PPP_FILTER */
155 struct net *ppp_net; /* the net we belong to */
156 struct ppp_link_stats stats64; /* 64 bit network stats */
160 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
161 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
163 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
164 * Bits in xstate: SC_COMP_RUN
166 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
167 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
168 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
171 * Private data structure for each channel.
172 * This includes the data structure used for multilink.
175 struct ppp_file file; /* stuff for read/write/poll */
176 struct list_head list; /* link in all/new_channels list */
177 struct ppp_channel *chan; /* public channel data structure */
178 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
179 spinlock_t downl; /* protects `chan', file.xq dequeue */
180 struct ppp *ppp; /* ppp unit we're connected to */
181 struct net *chan_net; /* the net channel belongs to */
182 struct list_head clist; /* link in list of channels per unit */
183 rwlock_t upl; /* protects `ppp' */
184 #ifdef CONFIG_PPP_MULTILINK
185 u8 avail; /* flag used in multilink stuff */
186 u8 had_frag; /* >= 1 fragments have been sent */
187 u32 lastseq; /* MP: last sequence # received */
188 int speed; /* speed of the corresponding ppp channel*/
189 #endif /* CONFIG_PPP_MULTILINK */
199 * SMP locking issues:
200 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
201 * list and the ppp.n_channels field, you need to take both locks
202 * before you modify them.
203 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
207 static DEFINE_MUTEX(ppp_mutex);
208 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
209 static atomic_t channel_count = ATOMIC_INIT(0);
211 /* per-net private data for this module */
212 static unsigned int ppp_net_id __read_mostly;
214 /* units to ppp mapping */
215 struct idr units_idr;
218 * all_ppp_mutex protects the units_idr mapping.
219 * It also ensures that finding a ppp unit in the units_idr
220 * map and updating its file.refcnt field is atomic.
222 struct mutex all_ppp_mutex;
225 struct list_head all_channels;
226 struct list_head new_channels;
227 int last_channel_index;
230 * all_channels_lock protects all_channels and
231 * last_channel_index, and the atomicity of find
232 * a channel and updating its file.refcnt field.
234 spinlock_t all_channels_lock;
237 /* Get the PPP protocol number from a skb */
238 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data)
240 /* We limit the length of ppp->file.rq to this (arbitrary) value */
241 #define PPP_MAX_RQLEN 32
244 * Maximum number of multilink fragments queued up.
245 * This has to be large enough to cope with the maximum latency of
246 * the slowest channel relative to the others. Strictly it should
247 * depend on the number of channels and their characteristics.
249 #define PPP_MP_MAX_QLEN 128
251 /* Multilink header bits. */
252 #define B 0x80 /* this fragment begins a packet */
253 #define E 0x40 /* this fragment ends a packet */
255 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
256 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
257 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
260 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
261 struct file *file, unsigned int cmd, unsigned long arg);
262 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb);
263 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
264 static void ppp_push(struct ppp *ppp);
265 static void ppp_channel_push(struct channel *pch);
266 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
267 struct channel *pch);
268 static void ppp_receive_error(struct ppp *ppp);
269 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
270 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
271 struct sk_buff *skb);
272 #ifdef CONFIG_PPP_MULTILINK
273 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
274 struct channel *pch);
275 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
276 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
277 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
278 #endif /* CONFIG_PPP_MULTILINK */
279 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
280 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
281 static void ppp_ccp_closed(struct ppp *ppp);
282 static struct compressor *find_compressor(int type);
283 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
284 static int ppp_create_interface(struct net *net, struct file *file, int *unit);
285 static void init_ppp_file(struct ppp_file *pf, int kind);
286 static void ppp_destroy_interface(struct ppp *ppp);
287 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
288 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
289 static int ppp_connect_channel(struct channel *pch, int unit);
290 static int ppp_disconnect_channel(struct channel *pch);
291 static void ppp_destroy_channel(struct channel *pch);
292 static int unit_get(struct idr *p, void *ptr, int min);
293 static int unit_set(struct idr *p, void *ptr, int n);
294 static void unit_put(struct idr *p, int n);
295 static void *unit_find(struct idr *p, int n);
296 static void ppp_setup(struct net_device *dev);
298 static const struct net_device_ops ppp_netdev_ops;
300 static struct class *ppp_class;
302 /* per net-namespace data */
303 static inline struct ppp_net *ppp_pernet(struct net *net)
307 return net_generic(net, ppp_net_id);
310 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
311 static inline int proto_to_npindex(int proto)
330 /* Translates an NP index into a PPP protocol number */
331 static const int npindex_to_proto[NUM_NP] = {
340 /* Translates an ethertype into an NP index */
341 static inline int ethertype_to_npindex(int ethertype)
361 /* Translates an NP index into an ethertype */
362 static const int npindex_to_ethertype[NUM_NP] = {
374 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
375 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
376 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
377 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
378 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
379 ppp_recv_lock(ppp); } while (0)
380 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
381 ppp_xmit_unlock(ppp); } while (0)
384 * /dev/ppp device routines.
385 * The /dev/ppp device is used by pppd to control the ppp unit.
386 * It supports the read, write, ioctl and poll functions.
387 * Open instances of /dev/ppp can be in one of three states:
388 * unattached, attached to a ppp unit, or attached to a ppp channel.
390 static int ppp_open(struct inode *inode, struct file *file)
393 * This could (should?) be enforced by the permissions on /dev/ppp.
395 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN))
400 static int ppp_release(struct inode *unused, struct file *file)
402 struct ppp_file *pf = file->private_data;
406 file->private_data = NULL;
407 if (pf->kind == INTERFACE) {
410 if (file == ppp->owner)
411 unregister_netdevice(ppp->dev);
414 if (refcount_dec_and_test(&pf->refcnt)) {
417 ppp_destroy_interface(PF_TO_PPP(pf));
420 ppp_destroy_channel(PF_TO_CHANNEL(pf));
428 static ssize_t ppp_read(struct file *file, char __user *buf,
429 size_t count, loff_t *ppos)
431 struct ppp_file *pf = file->private_data;
432 DECLARE_WAITQUEUE(wait, current);
434 struct sk_buff *skb = NULL;
442 add_wait_queue(&pf->rwait, &wait);
444 set_current_state(TASK_INTERRUPTIBLE);
445 skb = skb_dequeue(&pf->rq);
451 if (pf->kind == INTERFACE) {
453 * Return 0 (EOF) on an interface that has no
454 * channels connected, unless it is looping
455 * network traffic (demand mode).
457 struct ppp *ppp = PF_TO_PPP(pf);
460 if (ppp->n_channels == 0 &&
461 (ppp->flags & SC_LOOP_TRAFFIC) == 0) {
462 ppp_recv_unlock(ppp);
465 ppp_recv_unlock(ppp);
468 if (file->f_flags & O_NONBLOCK)
471 if (signal_pending(current))
475 set_current_state(TASK_RUNNING);
476 remove_wait_queue(&pf->rwait, &wait);
482 if (skb->len > count)
487 iov_iter_init(&to, READ, &iov, 1, count);
488 if (skb_copy_datagram_iter(skb, 0, &to, skb->len))
498 static ssize_t ppp_write(struct file *file, const char __user *buf,
499 size_t count, loff_t *ppos)
501 struct ppp_file *pf = file->private_data;
507 /* All PPP packets should start with the 2-byte protocol */
508 if (count < PPP_PROTO_LEN)
511 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
514 skb_reserve(skb, pf->hdrlen);
516 if (copy_from_user(skb_put(skb, count), buf, count)) {
523 ppp_xmit_process(PF_TO_PPP(pf), skb);
526 skb_queue_tail(&pf->xq, skb);
527 ppp_channel_push(PF_TO_CHANNEL(pf));
537 /* No kernel lock - fine */
538 static __poll_t ppp_poll(struct file *file, poll_table *wait)
540 struct ppp_file *pf = file->private_data;
545 poll_wait(file, &pf->rwait, wait);
546 mask = EPOLLOUT | EPOLLWRNORM;
547 if (skb_peek(&pf->rq))
548 mask |= EPOLLIN | EPOLLRDNORM;
551 else if (pf->kind == INTERFACE) {
552 /* see comment in ppp_read */
553 struct ppp *ppp = PF_TO_PPP(pf);
556 if (ppp->n_channels == 0 &&
557 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
558 mask |= EPOLLIN | EPOLLRDNORM;
559 ppp_recv_unlock(ppp);
565 #ifdef CONFIG_PPP_FILTER
566 static int get_filter(void __user *arg, struct sock_filter **p)
568 struct sock_fprog uprog;
569 struct sock_filter *code = NULL;
572 if (copy_from_user(&uprog, arg, sizeof(uprog)))
580 len = uprog.len * sizeof(struct sock_filter);
581 code = memdup_user(uprog.filter, len);
583 return PTR_ERR(code);
588 #endif /* CONFIG_PPP_FILTER */
590 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
594 int err = -EFAULT, val, val2, i;
595 struct ppp_idle idle;
598 struct slcompress *vj;
599 void __user *argp = (void __user *)arg;
600 int __user *p = argp;
602 mutex_lock(&ppp_mutex);
604 pf = file->private_data;
606 err = ppp_unattached_ioctl(current->nsproxy->net_ns,
611 if (cmd == PPPIOCDETACH) {
613 * PPPIOCDETACH is no longer supported as it was heavily broken,
614 * and is only known to have been used by pppd older than
615 * ppp-2.4.2 (released November 2003).
617 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n",
618 current->comm, current->pid);
623 if (pf->kind == CHANNEL) {
625 struct ppp_channel *chan;
627 pch = PF_TO_CHANNEL(pf);
631 if (get_user(unit, p))
633 err = ppp_connect_channel(pch, unit);
637 err = ppp_disconnect_channel(pch);
641 down_read(&pch->chan_sem);
644 if (chan && chan->ops->ioctl)
645 err = chan->ops->ioctl(chan, cmd, arg);
646 up_read(&pch->chan_sem);
651 if (pf->kind != INTERFACE) {
653 pr_err("PPP: not interface or channel??\n");
661 if (get_user(val, p))
668 if (get_user(val, p))
671 cflags = ppp->flags & ~val;
672 #ifdef CONFIG_PPP_MULTILINK
673 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK))
676 ppp->flags = val & SC_FLAG_BITS;
678 if (cflags & SC_CCP_OPEN)
684 val = ppp->flags | ppp->xstate | ppp->rstate;
685 if (put_user(val, p))
690 case PPPIOCSCOMPRESS:
691 err = ppp_set_compress(ppp, arg);
695 if (put_user(ppp->file.index, p))
701 if (get_user(val, p))
708 if (put_user(ppp->debug, p))
714 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
715 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
716 if (copy_to_user(argp, &idle, sizeof(idle)))
722 if (get_user(val, p))
725 if ((val >> 16) != 0) {
729 vj = slhc_init(val2+1, val+1);
744 if (copy_from_user(&npi, argp, sizeof(npi)))
746 err = proto_to_npindex(npi.protocol);
750 if (cmd == PPPIOCGNPMODE) {
752 npi.mode = ppp->npmode[i];
753 if (copy_to_user(argp, &npi, sizeof(npi)))
756 ppp->npmode[i] = npi.mode;
757 /* we may be able to transmit more packets now (??) */
758 netif_wake_queue(ppp->dev);
763 #ifdef CONFIG_PPP_FILTER
766 struct sock_filter *code;
768 err = get_filter(argp, &code);
770 struct bpf_prog *pass_filter = NULL;
771 struct sock_fprog_kern fprog = {
778 err = bpf_prog_create(&pass_filter, &fprog);
781 if (ppp->pass_filter)
782 bpf_prog_destroy(ppp->pass_filter);
783 ppp->pass_filter = pass_filter;
792 struct sock_filter *code;
794 err = get_filter(argp, &code);
796 struct bpf_prog *active_filter = NULL;
797 struct sock_fprog_kern fprog = {
804 err = bpf_prog_create(&active_filter, &fprog);
807 if (ppp->active_filter)
808 bpf_prog_destroy(ppp->active_filter);
809 ppp->active_filter = active_filter;
816 #endif /* CONFIG_PPP_FILTER */
818 #ifdef CONFIG_PPP_MULTILINK
820 if (get_user(val, p))
824 ppp_recv_unlock(ppp);
827 #endif /* CONFIG_PPP_MULTILINK */
834 mutex_unlock(&ppp_mutex);
839 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
840 struct file *file, unsigned int cmd, unsigned long arg)
842 int unit, err = -EFAULT;
844 struct channel *chan;
846 int __user *p = (int __user *)arg;
850 /* Create a new ppp unit */
851 if (get_user(unit, p))
853 err = ppp_create_interface(net, file, &unit);
858 if (put_user(unit, p))
864 /* Attach to an existing ppp unit */
865 if (get_user(unit, p))
868 pn = ppp_pernet(net);
869 mutex_lock(&pn->all_ppp_mutex);
870 ppp = ppp_find_unit(pn, unit);
872 refcount_inc(&ppp->file.refcnt);
873 file->private_data = &ppp->file;
876 mutex_unlock(&pn->all_ppp_mutex);
880 if (get_user(unit, p))
883 pn = ppp_pernet(net);
884 spin_lock_bh(&pn->all_channels_lock);
885 chan = ppp_find_channel(pn, unit);
887 refcount_inc(&chan->file.refcnt);
888 file->private_data = &chan->file;
891 spin_unlock_bh(&pn->all_channels_lock);
901 static const struct file_operations ppp_device_fops = {
902 .owner = THIS_MODULE,
906 .unlocked_ioctl = ppp_ioctl,
908 .release = ppp_release,
909 .llseek = noop_llseek,
912 static __net_init int ppp_init_net(struct net *net)
914 struct ppp_net *pn = net_generic(net, ppp_net_id);
916 idr_init(&pn->units_idr);
917 mutex_init(&pn->all_ppp_mutex);
919 INIT_LIST_HEAD(&pn->all_channels);
920 INIT_LIST_HEAD(&pn->new_channels);
922 spin_lock_init(&pn->all_channels_lock);
927 static __net_exit void ppp_exit_net(struct net *net)
929 struct ppp_net *pn = net_generic(net, ppp_net_id);
930 struct net_device *dev;
931 struct net_device *aux;
937 for_each_netdev_safe(net, dev, aux) {
938 if (dev->netdev_ops == &ppp_netdev_ops)
939 unregister_netdevice_queue(dev, &list);
942 idr_for_each_entry(&pn->units_idr, ppp, id)
943 /* Skip devices already unregistered by previous loop */
944 if (!net_eq(dev_net(ppp->dev), net))
945 unregister_netdevice_queue(ppp->dev, &list);
947 unregister_netdevice_many(&list);
950 mutex_destroy(&pn->all_ppp_mutex);
951 idr_destroy(&pn->units_idr);
952 WARN_ON_ONCE(!list_empty(&pn->all_channels));
953 WARN_ON_ONCE(!list_empty(&pn->new_channels));
956 static struct pernet_operations ppp_net_ops = {
957 .init = ppp_init_net,
958 .exit = ppp_exit_net,
960 .size = sizeof(struct ppp_net),
963 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
965 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
968 mutex_lock(&pn->all_ppp_mutex);
971 ret = unit_get(&pn->units_idr, ppp, 0);
974 if (!ifname_is_set) {
976 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret);
977 if (!__dev_get_by_name(ppp->ppp_net, ppp->dev->name))
979 unit_put(&pn->units_idr, ret);
980 ret = unit_get(&pn->units_idr, ppp, ret + 1);
986 /* Caller asked for a specific unit number. Fail with -EEXIST
987 * if unavailable. For backward compatibility, return -EEXIST
988 * too if idr allocation fails; this makes pppd retry without
989 * requesting a specific unit number.
991 if (unit_find(&pn->units_idr, unit)) {
995 ret = unit_set(&pn->units_idr, ppp, unit);
997 /* Rewrite error for backward compatibility */
1002 ppp->file.index = ret;
1005 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);
1007 mutex_unlock(&pn->all_ppp_mutex);
1009 ret = register_netdevice(ppp->dev);
1013 atomic_inc(&ppp_unit_count);
1018 mutex_lock(&pn->all_ppp_mutex);
1019 unit_put(&pn->units_idr, ppp->file.index);
1021 mutex_unlock(&pn->all_ppp_mutex);
1026 static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
1027 const struct ppp_config *conf)
1029 struct ppp *ppp = netdev_priv(dev);
1035 ppp->ppp_net = src_net;
1037 ppp->owner = conf->file;
1039 init_ppp_file(&ppp->file, INTERFACE);
1040 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
1042 for (indx = 0; indx < NUM_NP; ++indx)
1043 ppp->npmode[indx] = NPMODE_PASS;
1044 INIT_LIST_HEAD(&ppp->channels);
1045 spin_lock_init(&ppp->rlock);
1046 spin_lock_init(&ppp->wlock);
1048 ppp->xmit_recursion = alloc_percpu(int);
1049 if (!ppp->xmit_recursion) {
1053 for_each_possible_cpu(cpu)
1054 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
1056 #ifdef CONFIG_PPP_MULTILINK
1058 skb_queue_head_init(&ppp->mrq);
1059 #endif /* CONFIG_PPP_MULTILINK */
1060 #ifdef CONFIG_PPP_FILTER
1061 ppp->pass_filter = NULL;
1062 ppp->active_filter = NULL;
1063 #endif /* CONFIG_PPP_FILTER */
1065 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
1069 conf->file->private_data = &ppp->file;
1073 free_percpu(ppp->xmit_recursion);
1078 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
1079 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 },
1082 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[],
1083 struct netlink_ext_ack *extack)
1088 if (!data[IFLA_PPP_DEV_FD])
1090 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
1096 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
1097 struct nlattr *tb[], struct nlattr *data[],
1098 struct netlink_ext_ack *extack)
1100 struct ppp_config conf = {
1102 .ifname_is_set = true,
1107 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
1111 /* rtnl_lock is already held here, but ppp_create_interface() locks
1112 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
1113 * possible deadlock due to lock order inversion, at the cost of
1114 * pushing the problem back to userspace.
1116 if (!mutex_trylock(&ppp_mutex)) {
1121 if (file->f_op != &ppp_device_fops || file->private_data) {
1128 /* Don't use device name generated by the rtnetlink layer when ifname
1129 * isn't specified. Let ppp_dev_configure() set the device name using
1130 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows
1131 * userspace to infer the device name using to the PPPIOCGUNIT ioctl.
1133 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME]))
1134 conf.ifname_is_set = false;
1136 err = ppp_dev_configure(src_net, dev, &conf);
1139 mutex_unlock(&ppp_mutex);
1146 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
1148 unregister_netdevice_queue(dev, head);
1151 static size_t ppp_nl_get_size(const struct net_device *dev)
1156 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1161 static struct net *ppp_nl_get_link_net(const struct net_device *dev)
1163 struct ppp *ppp = netdev_priv(dev);
1165 return ppp->ppp_net;
1168 static struct rtnl_link_ops ppp_link_ops __read_mostly = {
1170 .maxtype = IFLA_PPP_MAX,
1171 .policy = ppp_nl_policy,
1172 .priv_size = sizeof(struct ppp),
1174 .validate = ppp_nl_validate,
1175 .newlink = ppp_nl_newlink,
1176 .dellink = ppp_nl_dellink,
1177 .get_size = ppp_nl_get_size,
1178 .fill_info = ppp_nl_fill_info,
1179 .get_link_net = ppp_nl_get_link_net,
1182 #define PPP_MAJOR 108
1184 /* Called at boot time if ppp is compiled into the kernel,
1185 or at module load time (from init_module) if compiled as a module. */
1186 static int __init ppp_init(void)
1190 pr_info("PPP generic driver version " PPP_VERSION "\n");
1192 err = register_pernet_device(&ppp_net_ops);
1194 pr_err("failed to register PPP pernet device (%d)\n", err);
1198 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
1200 pr_err("failed to register PPP device (%d)\n", err);
1204 ppp_class = class_create(THIS_MODULE, "ppp");
1205 if (IS_ERR(ppp_class)) {
1206 err = PTR_ERR(ppp_class);
1210 err = rtnl_link_register(&ppp_link_ops);
1212 pr_err("failed to register rtnetlink PPP handler\n");
1216 /* not a big deal if we fail here :-) */
1217 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
1222 class_destroy(ppp_class);
1224 unregister_chrdev(PPP_MAJOR, "ppp");
1226 unregister_pernet_device(&ppp_net_ops);
1232 * Network interface unit routines.
1235 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
1237 struct ppp *ppp = netdev_priv(dev);
1241 npi = ethertype_to_npindex(ntohs(skb->protocol));
1245 /* Drop, accept or reject the packet */
1246 switch (ppp->npmode[npi]) {
1250 /* it would be nice to have a way to tell the network
1251 system to queue this one up for later. */
1258 /* Put the 2-byte PPP protocol number on the front,
1259 making sure there is room for the address and control fields. */
1260 if (skb_cow_head(skb, PPP_HDRLEN))
1263 pp = skb_push(skb, 2);
1264 proto = npindex_to_proto[npi];
1265 put_unaligned_be16(proto, pp);
1267 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev)));
1268 ppp_xmit_process(ppp, skb);
1270 return NETDEV_TX_OK;
1274 ++dev->stats.tx_dropped;
1275 return NETDEV_TX_OK;
1279 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1281 struct ppp *ppp = netdev_priv(dev);
1283 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1284 struct ppp_stats stats;
1285 struct ppp_comp_stats cstats;
1290 ppp_get_stats(ppp, &stats);
1291 if (copy_to_user(addr, &stats, sizeof(stats)))
1296 case SIOCGPPPCSTATS:
1297 memset(&cstats, 0, sizeof(cstats));
1299 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1301 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1302 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1309 if (copy_to_user(addr, vers, strlen(vers) + 1))
1322 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
1324 struct ppp *ppp = netdev_priv(dev);
1327 stats64->rx_packets = ppp->stats64.rx_packets;
1328 stats64->rx_bytes = ppp->stats64.rx_bytes;
1329 ppp_recv_unlock(ppp);
1332 stats64->tx_packets = ppp->stats64.tx_packets;
1333 stats64->tx_bytes = ppp->stats64.tx_bytes;
1334 ppp_xmit_unlock(ppp);
1336 stats64->rx_errors = dev->stats.rx_errors;
1337 stats64->tx_errors = dev->stats.tx_errors;
1338 stats64->rx_dropped = dev->stats.rx_dropped;
1339 stats64->tx_dropped = dev->stats.tx_dropped;
1340 stats64->rx_length_errors = dev->stats.rx_length_errors;
1343 static int ppp_dev_init(struct net_device *dev)
1347 netdev_lockdep_set_classes(dev);
1349 ppp = netdev_priv(dev);
1350 /* Let the netdevice take a reference on the ppp file. This ensures
1351 * that ppp_destroy_interface() won't run before the device gets
1354 refcount_inc(&ppp->file.refcnt);
1359 static void ppp_dev_uninit(struct net_device *dev)
1361 struct ppp *ppp = netdev_priv(dev);
1362 struct ppp_net *pn = ppp_pernet(ppp->ppp_net);
1368 mutex_lock(&pn->all_ppp_mutex);
1369 unit_put(&pn->units_idr, ppp->file.index);
1370 mutex_unlock(&pn->all_ppp_mutex);
1375 wake_up_interruptible(&ppp->file.rwait);
1378 static void ppp_dev_priv_destructor(struct net_device *dev)
1382 ppp = netdev_priv(dev);
1383 if (refcount_dec_and_test(&ppp->file.refcnt))
1384 ppp_destroy_interface(ppp);
1387 static const struct net_device_ops ppp_netdev_ops = {
1388 .ndo_init = ppp_dev_init,
1389 .ndo_uninit = ppp_dev_uninit,
1390 .ndo_start_xmit = ppp_start_xmit,
1391 .ndo_do_ioctl = ppp_net_ioctl,
1392 .ndo_get_stats64 = ppp_get_stats64,
1395 static struct device_type ppp_type = {
1399 static void ppp_setup(struct net_device *dev)
1401 dev->netdev_ops = &ppp_netdev_ops;
1402 SET_NETDEV_DEVTYPE(dev, &ppp_type);
1404 dev->features |= NETIF_F_LLTX;
1406 dev->hard_header_len = PPP_HDRLEN;
1409 dev->tx_queue_len = 3;
1410 dev->type = ARPHRD_PPP;
1411 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1412 dev->priv_destructor = ppp_dev_priv_destructor;
1413 netif_keep_dst(dev);
1417 * Transmit-side routines.
1420 /* Called to do any work queued up on the transmit side that can now be done */
1421 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1424 if (!ppp->closing) {
1428 skb_queue_tail(&ppp->file.xq, skb);
1429 while (!ppp->xmit_pending &&
1430 (skb = skb_dequeue(&ppp->file.xq)))
1431 ppp_send_frame(ppp, skb);
1432 /* If there's no work left to do, tell the core net
1433 code that we can accept some more. */
1434 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1435 netif_wake_queue(ppp->dev);
1437 netif_stop_queue(ppp->dev);
1441 ppp_xmit_unlock(ppp);
1444 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb)
1448 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
1451 (*this_cpu_ptr(ppp->xmit_recursion))++;
1452 __ppp_xmit_process(ppp, skb);
1453 (*this_cpu_ptr(ppp->xmit_recursion))--;
1464 if (net_ratelimit())
1465 netdev_err(ppp->dev, "recursion detected\n");
1468 static inline struct sk_buff *
1469 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1471 struct sk_buff *new_skb;
1473 int new_skb_size = ppp->dev->mtu +
1474 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1475 int compressor_skb_size = ppp->dev->mtu +
1476 ppp->xcomp->comp_extra + PPP_HDRLEN;
1477 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1479 if (net_ratelimit())
1480 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n");
1483 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1484 skb_reserve(new_skb,
1485 ppp->dev->hard_header_len - PPP_HDRLEN);
1487 /* compressor still expects A/C bytes in hdr */
1488 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1489 new_skb->data, skb->len + 2,
1490 compressor_skb_size);
1491 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1495 skb_pull(skb, 2); /* pull off A/C bytes */
1496 } else if (len == 0) {
1497 /* didn't compress, or CCP not up yet */
1498 consume_skb(new_skb);
1503 * MPPE requires that we do not send unencrypted
1504 * frames. The compressor will return -1 if we
1505 * should drop the frame. We cannot simply test
1506 * the compress_proto because MPPE and MPPC share
1509 if (net_ratelimit())
1510 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n");
1512 consume_skb(new_skb);
1519 * Compress and send a frame.
1520 * The caller should have locked the xmit path,
1521 * and xmit_pending should be 0.
1524 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1526 int proto = PPP_PROTO(skb);
1527 struct sk_buff *new_skb;
1531 skb->dev = ppp->dev;
1533 if (proto < 0x8000) {
1534 #ifdef CONFIG_PPP_FILTER
1535 /* check if we should pass this packet */
1536 /* the filter instructions are constructed assuming
1537 a four-byte PPP header on each packet */
1538 *(u8 *)skb_push(skb, 2) = 1;
1539 if (ppp->pass_filter &&
1540 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
1542 netdev_printk(KERN_DEBUG, ppp->dev,
1543 "PPP: outbound frame "
1548 /* if this packet passes the active filter, record the time */
1549 if (!(ppp->active_filter &&
1550 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
1551 ppp->last_xmit = jiffies;
1554 /* for data packets, record the time */
1555 ppp->last_xmit = jiffies;
1556 #endif /* CONFIG_PPP_FILTER */
1559 ++ppp->stats64.tx_packets;
1560 ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN;
1564 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1566 /* try to do VJ TCP header compression */
1567 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1570 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n");
1573 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1575 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1576 new_skb->data + 2, &cp,
1577 !(ppp->flags & SC_NO_TCP_CCID));
1578 if (cp == skb->data + 2) {
1579 /* didn't compress */
1580 consume_skb(new_skb);
1582 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1583 proto = PPP_VJC_COMP;
1584 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1586 proto = PPP_VJC_UNCOMP;
1587 cp[0] = skb->data[2];
1591 cp = skb_put(skb, len + 2);
1598 /* peek at outbound CCP frames */
1599 ppp_ccp_peek(ppp, skb, 0);
1603 /* try to do packet compression */
1604 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1605 proto != PPP_LCP && proto != PPP_CCP) {
1606 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1607 if (net_ratelimit())
1608 netdev_err(ppp->dev,
1609 "ppp: compression required but "
1610 "down - pkt dropped.\n");
1613 skb = pad_compress_skb(ppp, skb);
1619 * If we are waiting for traffic (demand dialling),
1620 * queue it up for pppd to receive.
1622 if (ppp->flags & SC_LOOP_TRAFFIC) {
1623 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1625 skb_queue_tail(&ppp->file.rq, skb);
1626 wake_up_interruptible(&ppp->file.rwait);
1630 ppp->xmit_pending = skb;
1636 ++ppp->dev->stats.tx_errors;
1640 * Try to send the frame in xmit_pending.
1641 * The caller should have the xmit path locked.
1644 ppp_push(struct ppp *ppp)
1646 struct list_head *list;
1647 struct channel *pch;
1648 struct sk_buff *skb = ppp->xmit_pending;
1653 list = &ppp->channels;
1654 if (list_empty(list)) {
1655 /* nowhere to send the packet, just drop it */
1656 ppp->xmit_pending = NULL;
1661 if ((ppp->flags & SC_MULTILINK) == 0) {
1662 /* not doing multilink: send it down the first channel */
1664 pch = list_entry(list, struct channel, clist);
1666 spin_lock(&pch->downl);
1668 if (pch->chan->ops->start_xmit(pch->chan, skb))
1669 ppp->xmit_pending = NULL;
1671 /* channel got unregistered */
1673 ppp->xmit_pending = NULL;
1675 spin_unlock(&pch->downl);
1679 #ifdef CONFIG_PPP_MULTILINK
1680 /* Multilink: fragment the packet over as many links
1681 as can take the packet at the moment. */
1682 if (!ppp_mp_explode(ppp, skb))
1684 #endif /* CONFIG_PPP_MULTILINK */
1686 ppp->xmit_pending = NULL;
1690 #ifdef CONFIG_PPP_MULTILINK
1691 static bool mp_protocol_compress __read_mostly = true;
1692 module_param(mp_protocol_compress, bool, 0644);
1693 MODULE_PARM_DESC(mp_protocol_compress,
1694 "compress protocol id in multilink fragments");
1697 * Divide a packet to be transmitted into fragments and
1698 * send them out the individual links.
1700 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1703 int i, bits, hdrlen, mtu;
1705 int navail, nfree, nzero;
1709 unsigned char *p, *q;
1710 struct list_head *list;
1711 struct channel *pch;
1712 struct sk_buff *frag;
1713 struct ppp_channel *chan;
1715 totspeed = 0; /*total bitrate of the bundle*/
1716 nfree = 0; /* # channels which have no packet already queued */
1717 navail = 0; /* total # of usable channels (not deregistered) */
1718 nzero = 0; /* number of channels with zero speed associated*/
1719 totfree = 0; /*total # of channels available and
1720 *having no queued packets before
1721 *starting the fragmentation*/
1723 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1725 list_for_each_entry(pch, &ppp->channels, clist) {
1729 pch->speed = pch->chan->speed;
1734 if (skb_queue_empty(&pch->file.xq) ||
1736 if (pch->speed == 0)
1739 totspeed += pch->speed;
1745 if (!pch->had_frag && i < ppp->nxchan)
1751 * Don't start sending this packet unless at least half of
1752 * the channels are free. This gives much better TCP
1753 * performance if we have a lot of channels.
1755 if (nfree == 0 || nfree < navail / 2)
1756 return 0; /* can't take now, leave it in xmit_pending */
1758 /* Do protocol field compression */
1761 if (*p == 0 && mp_protocol_compress) {
1767 nbigger = len % nfree;
1769 /* skip to the channel after the one we last used
1770 and start at that one */
1771 list = &ppp->channels;
1772 for (i = 0; i < ppp->nxchan; ++i) {
1774 if (list == &ppp->channels) {
1780 /* create a fragment for each channel */
1784 if (list == &ppp->channels) {
1788 pch = list_entry(list, struct channel, clist);
1794 * Skip this channel if it has a fragment pending already and
1795 * we haven't given a fragment to all of the free channels.
1797 if (pch->avail == 1) {
1804 /* check the channel's mtu and whether it is still attached. */
1805 spin_lock(&pch->downl);
1806 if (pch->chan == NULL) {
1807 /* can't use this channel, it's being deregistered */
1808 if (pch->speed == 0)
1811 totspeed -= pch->speed;
1813 spin_unlock(&pch->downl);
1824 *if the channel speed is not set divide
1825 *the packet evenly among the free channels;
1826 *otherwise divide it according to the speed
1827 *of the channel we are going to transmit on
1831 if (pch->speed == 0) {
1838 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1839 ((totspeed*totfree)/pch->speed)) - hdrlen;
1841 flen += ((totfree - nzero)*pch->speed)/totspeed;
1842 nbigger -= ((totfree - nzero)*pch->speed)/
1850 *check if we are on the last channel or
1851 *we exceded the length of the data to
1854 if ((nfree <= 0) || (flen > len))
1857 *it is not worth to tx on slow channels:
1858 *in that case from the resulting flen according to the
1859 *above formula will be equal or less than zero.
1860 *Skip the channel in this case
1864 spin_unlock(&pch->downl);
1869 * hdrlen includes the 2-byte PPP protocol field, but the
1870 * MTU counts only the payload excluding the protocol field.
1871 * (RFC1661 Section 2)
1873 mtu = pch->chan->mtu - (hdrlen - 2);
1880 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1883 q = skb_put(frag, flen + hdrlen);
1885 /* make the MP header */
1886 put_unaligned_be16(PPP_MP, q);
1887 if (ppp->flags & SC_MP_XSHORTSEQ) {
1888 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1892 q[3] = ppp->nxseq >> 16;
1893 q[4] = ppp->nxseq >> 8;
1897 memcpy(q + hdrlen, p, flen);
1899 /* try to send it down the channel */
1901 if (!skb_queue_empty(&pch->file.xq) ||
1902 !chan->ops->start_xmit(chan, frag))
1903 skb_queue_tail(&pch->file.xq, frag);
1909 spin_unlock(&pch->downl);
1916 spin_unlock(&pch->downl);
1918 netdev_err(ppp->dev, "PPP: no memory (fragment)\n");
1919 ++ppp->dev->stats.tx_errors;
1921 return 1; /* abandon the frame */
1923 #endif /* CONFIG_PPP_MULTILINK */
1925 /* Try to send data out on a channel */
1926 static void __ppp_channel_push(struct channel *pch)
1928 struct sk_buff *skb;
1931 spin_lock(&pch->downl);
1933 while (!skb_queue_empty(&pch->file.xq)) {
1934 skb = skb_dequeue(&pch->file.xq);
1935 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1936 /* put the packet back and try again later */
1937 skb_queue_head(&pch->file.xq, skb);
1942 /* channel got deregistered */
1943 skb_queue_purge(&pch->file.xq);
1945 spin_unlock(&pch->downl);
1946 /* see if there is anything from the attached unit to be sent */
1947 if (skb_queue_empty(&pch->file.xq)) {
1950 __ppp_xmit_process(ppp, NULL);
1954 static void ppp_channel_push(struct channel *pch)
1956 read_lock_bh(&pch->upl);
1958 (*this_cpu_ptr(pch->ppp->xmit_recursion))++;
1959 __ppp_channel_push(pch);
1960 (*this_cpu_ptr(pch->ppp->xmit_recursion))--;
1962 __ppp_channel_push(pch);
1964 read_unlock_bh(&pch->upl);
1968 * Receive-side routines.
1971 struct ppp_mp_skb_parm {
1975 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
1978 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1982 ppp_receive_frame(ppp, skb, pch);
1985 ppp_recv_unlock(ppp);
1989 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1991 struct channel *pch = chan->ppp;
1999 read_lock_bh(&pch->upl);
2000 if (!pskb_may_pull(skb, 2)) {
2003 ++pch->ppp->dev->stats.rx_length_errors;
2004 ppp_receive_error(pch->ppp);
2009 proto = PPP_PROTO(skb);
2010 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
2011 /* put it on the channel queue */
2012 skb_queue_tail(&pch->file.rq, skb);
2013 /* drop old frames if queue too long */
2014 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
2015 (skb = skb_dequeue(&pch->file.rq)))
2017 wake_up_interruptible(&pch->file.rwait);
2019 ppp_do_recv(pch->ppp, skb, pch);
2023 read_unlock_bh(&pch->upl);
2026 /* Put a 0-length skb in the receive queue as an error indication */
2028 ppp_input_error(struct ppp_channel *chan, int code)
2030 struct channel *pch = chan->ppp;
2031 struct sk_buff *skb;
2036 read_lock_bh(&pch->upl);
2038 skb = alloc_skb(0, GFP_ATOMIC);
2040 skb->len = 0; /* probably unnecessary */
2042 ppp_do_recv(pch->ppp, skb, pch);
2045 read_unlock_bh(&pch->upl);
2049 * We come in here to process a received frame.
2050 * The receive side of the ppp unit is locked.
2053 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2055 /* note: a 0-length skb is used as an error indication */
2057 skb_checksum_complete_unset(skb);
2058 #ifdef CONFIG_PPP_MULTILINK
2059 /* XXX do channel-level decompression here */
2060 if (PPP_PROTO(skb) == PPP_MP)
2061 ppp_receive_mp_frame(ppp, skb, pch);
2063 #endif /* CONFIG_PPP_MULTILINK */
2064 ppp_receive_nonmp_frame(ppp, skb);
2067 ppp_receive_error(ppp);
2072 ppp_receive_error(struct ppp *ppp)
2074 ++ppp->dev->stats.rx_errors;
2080 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
2083 int proto, len, npi;
2086 * Decompress the frame, if compressed.
2087 * Note that some decompressors need to see uncompressed frames
2088 * that come in as well as compressed frames.
2090 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
2091 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
2092 skb = ppp_decompress_frame(ppp, skb);
2094 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
2097 proto = PPP_PROTO(skb);
2100 /* decompress VJ compressed packets */
2101 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2104 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
2105 /* copy to a new sk_buff with more tailroom */
2106 ns = dev_alloc_skb(skb->len + 128);
2108 netdev_err(ppp->dev, "PPP: no memory "
2113 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
2118 skb->ip_summed = CHECKSUM_NONE;
2120 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
2122 netdev_printk(KERN_DEBUG, ppp->dev,
2123 "PPP: VJ decompression error\n");
2128 skb_put(skb, len - skb->len);
2129 else if (len < skb->len)
2134 case PPP_VJC_UNCOMP:
2135 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
2138 /* Until we fix the decompressor need to make sure
2139 * data portion is linear.
2141 if (!pskb_may_pull(skb, skb->len))
2144 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
2145 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n");
2152 ppp_ccp_peek(ppp, skb, 1);
2156 ++ppp->stats64.rx_packets;
2157 ppp->stats64.rx_bytes += skb->len - 2;
2159 npi = proto_to_npindex(proto);
2161 /* control or unknown frame - pass it to pppd */
2162 skb_queue_tail(&ppp->file.rq, skb);
2163 /* limit queue length by dropping old frames */
2164 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
2165 (skb = skb_dequeue(&ppp->file.rq)))
2167 /* wake up any process polling or blocking on read */
2168 wake_up_interruptible(&ppp->file.rwait);
2171 /* network protocol frame - give it to the kernel */
2173 #ifdef CONFIG_PPP_FILTER
2174 /* check if the packet passes the pass and active filters */
2175 /* the filter instructions are constructed assuming
2176 a four-byte PPP header on each packet */
2177 if (ppp->pass_filter || ppp->active_filter) {
2178 if (skb_unclone(skb, GFP_ATOMIC))
2181 *(u8 *)skb_push(skb, 2) = 0;
2182 if (ppp->pass_filter &&
2183 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {
2185 netdev_printk(KERN_DEBUG, ppp->dev,
2186 "PPP: inbound frame "
2191 if (!(ppp->active_filter &&
2192 BPF_PROG_RUN(ppp->active_filter, skb) == 0))
2193 ppp->last_recv = jiffies;
2196 #endif /* CONFIG_PPP_FILTER */
2197 ppp->last_recv = jiffies;
2199 if ((ppp->dev->flags & IFF_UP) == 0 ||
2200 ppp->npmode[npi] != NPMODE_PASS) {
2203 /* chop off protocol */
2204 skb_pull_rcsum(skb, 2);
2205 skb->dev = ppp->dev;
2206 skb->protocol = htons(npindex_to_ethertype[npi]);
2207 skb_reset_mac_header(skb);
2208 skb_scrub_packet(skb, !net_eq(ppp->ppp_net,
2209 dev_net(ppp->dev)));
2217 ppp_receive_error(ppp);
2220 static struct sk_buff *
2221 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
2223 int proto = PPP_PROTO(skb);
2227 /* Until we fix all the decompressor's need to make sure
2228 * data portion is linear.
2230 if (!pskb_may_pull(skb, skb->len))
2233 if (proto == PPP_COMP) {
2236 switch(ppp->rcomp->compress_proto) {
2238 obuff_size = ppp->mru + PPP_HDRLEN + 1;
2241 obuff_size = ppp->mru + PPP_HDRLEN;
2245 ns = dev_alloc_skb(obuff_size);
2247 netdev_err(ppp->dev, "ppp_decompress_frame: "
2251 /* the decompressor still expects the A/C bytes in the hdr */
2252 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
2253 skb->len + 2, ns->data, obuff_size);
2255 /* Pass the compressed frame to pppd as an
2256 error indication. */
2257 if (len == DECOMP_FATALERROR)
2258 ppp->rstate |= SC_DC_FERROR;
2266 skb_pull(skb, 2); /* pull off the A/C bytes */
2269 /* Uncompressed frame - pass to decompressor so it
2270 can update its dictionary if necessary. */
2271 if (ppp->rcomp->incomp)
2272 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
2279 ppp->rstate |= SC_DC_ERROR;
2280 ppp_receive_error(ppp);
2284 #ifdef CONFIG_PPP_MULTILINK
2286 * Receive a multilink frame.
2287 * We put it on the reconstruction queue and then pull off
2288 * as many completed frames as we can.
2291 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
2295 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
2297 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
2298 goto err; /* no good, throw it away */
2300 /* Decode sequence number and begin/end bits */
2301 if (ppp->flags & SC_MP_SHORTSEQ) {
2302 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
2305 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
2308 PPP_MP_CB(skb)->BEbits = skb->data[2];
2309 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
2312 * Do protocol ID decompression on the first fragment of each packet.
2314 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
2315 *(u8 *)skb_push(skb, 1) = 0;
2318 * Expand sequence number to 32 bits, making it as close
2319 * as possible to ppp->minseq.
2321 seq |= ppp->minseq & ~mask;
2322 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
2324 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
2325 seq -= mask + 1; /* should never happen */
2326 PPP_MP_CB(skb)->sequence = seq;
2330 * If this packet comes before the next one we were expecting,
2333 if (seq_before(seq, ppp->nextseq)) {
2335 ++ppp->dev->stats.rx_dropped;
2336 ppp_receive_error(ppp);
2341 * Reevaluate minseq, the minimum over all channels of the
2342 * last sequence number received on each channel. Because of
2343 * the increasing sequence number rule, we know that any fragment
2344 * before `minseq' which hasn't arrived is never going to arrive.
2345 * The list of channels can't change because we have the receive
2346 * side of the ppp unit locked.
2348 list_for_each_entry(ch, &ppp->channels, clist) {
2349 if (seq_before(ch->lastseq, seq))
2352 if (seq_before(ppp->minseq, seq))
2355 /* Put the fragment on the reconstruction queue */
2356 ppp_mp_insert(ppp, skb);
2358 /* If the queue is getting long, don't wait any longer for packets
2359 before the start of the queue. */
2360 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
2361 struct sk_buff *mskb = skb_peek(&ppp->mrq);
2362 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
2363 ppp->minseq = PPP_MP_CB(mskb)->sequence;
2366 /* Pull completed packets off the queue and receive them. */
2367 while ((skb = ppp_mp_reconstruct(ppp))) {
2368 if (pskb_may_pull(skb, 2))
2369 ppp_receive_nonmp_frame(ppp, skb);
2371 ++ppp->dev->stats.rx_length_errors;
2373 ppp_receive_error(ppp);
2381 ppp_receive_error(ppp);
2385 * Insert a fragment on the MP reconstruction queue.
2386 * The queue is ordered by increasing sequence number.
2389 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
2392 struct sk_buff_head *list = &ppp->mrq;
2393 u32 seq = PPP_MP_CB(skb)->sequence;
2395 /* N.B. we don't need to lock the list lock because we have the
2396 ppp unit receive-side lock. */
2397 skb_queue_walk(list, p) {
2398 if (seq_before(seq, PPP_MP_CB(p)->sequence))
2401 __skb_queue_before(list, p, skb);
2405 * Reconstruct a packet from the MP fragment queue.
2406 * We go through increasing sequence numbers until we find a
2407 * complete packet, or we get to the sequence number for a fragment
2408 * which hasn't arrived but might still do so.
2410 static struct sk_buff *
2411 ppp_mp_reconstruct(struct ppp *ppp)
2413 u32 seq = ppp->nextseq;
2414 u32 minseq = ppp->minseq;
2415 struct sk_buff_head *list = &ppp->mrq;
2416 struct sk_buff *p, *tmp;
2417 struct sk_buff *head, *tail;
2418 struct sk_buff *skb = NULL;
2419 int lost = 0, len = 0;
2421 if (ppp->mrru == 0) /* do nothing until mrru is set */
2425 skb_queue_walk_safe(list, p, tmp) {
2427 if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
2428 /* this can't happen, anyway ignore the skb */
2429 netdev_err(ppp->dev, "ppp_mp_reconstruct bad "
2431 PPP_MP_CB(p)->sequence, seq);
2432 __skb_unlink(p, list);
2436 if (PPP_MP_CB(p)->sequence != seq) {
2438 /* Fragment `seq' is missing. If it is after
2439 minseq, it might arrive later, so stop here. */
2440 if (seq_after(seq, minseq))
2442 /* Fragment `seq' is lost, keep going. */
2445 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
2446 minseq + 1: PPP_MP_CB(p)->sequence;
2449 netdev_printk(KERN_DEBUG, ppp->dev,
2450 "lost frag %u..%u\n",
2457 * At this point we know that all the fragments from
2458 * ppp->nextseq to seq are either present or lost.
2459 * Also, there are no complete packets in the queue
2460 * that have no missing fragments and end before this
2464 /* B bit set indicates this fragment starts a packet */
2465 if (PPP_MP_CB(p)->BEbits & B) {
2473 /* Got a complete packet yet? */
2474 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
2475 (PPP_MP_CB(head)->BEbits & B)) {
2476 if (len > ppp->mrru + 2) {
2477 ++ppp->dev->stats.rx_length_errors;
2478 netdev_printk(KERN_DEBUG, ppp->dev,
2479 "PPP: reconstructed packet"
2480 " is too long (%d)\n", len);
2485 ppp->nextseq = seq + 1;
2489 * If this is the ending fragment of a packet,
2490 * and we haven't found a complete valid packet yet,
2491 * we can discard up to and including this fragment.
2493 if (PPP_MP_CB(p)->BEbits & E) {
2494 struct sk_buff *tmp2;
2496 skb_queue_reverse_walk_from_safe(list, p, tmp2) {
2498 netdev_printk(KERN_DEBUG, ppp->dev,
2499 "discarding frag %u\n",
2500 PPP_MP_CB(p)->sequence);
2501 __skb_unlink(p, list);
2504 head = skb_peek(list);
2511 /* If we have a complete packet, copy it all into one skb. */
2513 /* If we have discarded any fragments,
2514 signal a receive error. */
2515 if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
2516 skb_queue_walk_safe(list, p, tmp) {
2520 netdev_printk(KERN_DEBUG, ppp->dev,
2521 "discarding frag %u\n",
2522 PPP_MP_CB(p)->sequence);
2523 __skb_unlink(p, list);
2528 netdev_printk(KERN_DEBUG, ppp->dev,
2529 " missed pkts %u..%u\n",
2531 PPP_MP_CB(head)->sequence-1);
2532 ++ppp->dev->stats.rx_dropped;
2533 ppp_receive_error(ppp);
2538 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list;
2539 p = skb_queue_next(list, head);
2540 __skb_unlink(skb, list);
2541 skb_queue_walk_from_safe(list, p, tmp) {
2542 __skb_unlink(p, list);
2548 skb->data_len += p->len;
2549 skb->truesize += p->truesize;
2555 __skb_unlink(skb, list);
2558 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
2563 #endif /* CONFIG_PPP_MULTILINK */
2566 * Channel interface.
2569 /* Create a new, unattached ppp channel. */
2570 int ppp_register_channel(struct ppp_channel *chan)
2572 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2575 /* Create a new, unattached ppp channel for specified net. */
2576 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2578 struct channel *pch;
2581 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2585 pn = ppp_pernet(net);
2589 pch->chan_net = get_net(net);
2591 init_ppp_file(&pch->file, CHANNEL);
2592 pch->file.hdrlen = chan->hdrlen;
2593 #ifdef CONFIG_PPP_MULTILINK
2595 #endif /* CONFIG_PPP_MULTILINK */
2596 init_rwsem(&pch->chan_sem);
2597 spin_lock_init(&pch->downl);
2598 rwlock_init(&pch->upl);
2600 spin_lock_bh(&pn->all_channels_lock);
2601 pch->file.index = ++pn->last_channel_index;
2602 list_add(&pch->list, &pn->new_channels);
2603 atomic_inc(&channel_count);
2604 spin_unlock_bh(&pn->all_channels_lock);
2610 * Return the index of a channel.
2612 int ppp_channel_index(struct ppp_channel *chan)
2614 struct channel *pch = chan->ppp;
2617 return pch->file.index;
2622 * Return the PPP unit number to which a channel is connected.
2624 int ppp_unit_number(struct ppp_channel *chan)
2626 struct channel *pch = chan->ppp;
2630 read_lock_bh(&pch->upl);
2632 unit = pch->ppp->file.index;
2633 read_unlock_bh(&pch->upl);
2639 * Return the PPP device interface name of a channel.
2641 char *ppp_dev_name(struct ppp_channel *chan)
2643 struct channel *pch = chan->ppp;
2647 read_lock_bh(&pch->upl);
2648 if (pch->ppp && pch->ppp->dev)
2649 name = pch->ppp->dev->name;
2650 read_unlock_bh(&pch->upl);
2657 * Disconnect a channel from the generic layer.
2658 * This must be called in process context.
2661 ppp_unregister_channel(struct ppp_channel *chan)
2663 struct channel *pch = chan->ppp;
2667 return; /* should never happen */
2672 * This ensures that we have returned from any calls into the
2673 * the channel's start_xmit or ioctl routine before we proceed.
2675 down_write(&pch->chan_sem);
2676 spin_lock_bh(&pch->downl);
2678 spin_unlock_bh(&pch->downl);
2679 up_write(&pch->chan_sem);
2680 ppp_disconnect_channel(pch);
2682 pn = ppp_pernet(pch->chan_net);
2683 spin_lock_bh(&pn->all_channels_lock);
2684 list_del(&pch->list);
2685 spin_unlock_bh(&pn->all_channels_lock);
2688 wake_up_interruptible(&pch->file.rwait);
2689 if (refcount_dec_and_test(&pch->file.refcnt))
2690 ppp_destroy_channel(pch);
2694 * Callback from a channel when it can accept more to transmit.
2695 * This should be called at BH/softirq level, not interrupt level.
2698 ppp_output_wakeup(struct ppp_channel *chan)
2700 struct channel *pch = chan->ppp;
2704 ppp_channel_push(pch);
2708 * Compression control.
2711 /* Process the PPPIOCSCOMPRESS ioctl. */
2713 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2716 struct compressor *cp, *ocomp;
2717 struct ppp_option_data data;
2718 void *state, *ostate;
2719 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2722 if (copy_from_user(&data, (void __user *) arg, sizeof(data)))
2724 if (data.length > CCP_MAX_OPTION_LENGTH)
2726 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length))
2730 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2733 cp = try_then_request_module(
2734 find_compressor(ccp_option[0]),
2735 "ppp-compress-%d", ccp_option[0]);
2740 if (data.transmit) {
2741 state = cp->comp_alloc(ccp_option, data.length);
2744 ppp->xstate &= ~SC_COMP_RUN;
2746 ostate = ppp->xc_state;
2748 ppp->xc_state = state;
2749 ppp_xmit_unlock(ppp);
2751 ocomp->comp_free(ostate);
2752 module_put(ocomp->owner);
2756 module_put(cp->owner);
2759 state = cp->decomp_alloc(ccp_option, data.length);
2762 ppp->rstate &= ~SC_DECOMP_RUN;
2764 ostate = ppp->rc_state;
2766 ppp->rc_state = state;
2767 ppp_recv_unlock(ppp);
2769 ocomp->decomp_free(ostate);
2770 module_put(ocomp->owner);
2774 module_put(cp->owner);
2782 * Look at a CCP packet and update our state accordingly.
2783 * We assume the caller has the xmit or recv path locked.
2786 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2791 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2792 return; /* no header */
2795 switch (CCP_CODE(dp)) {
2798 /* A ConfReq starts negotiation of compression
2799 * in one direction of transmission,
2800 * and hence brings it down...but which way?
2803 * A ConfReq indicates what the sender would like to receive
2806 /* He is proposing what I should send */
2807 ppp->xstate &= ~SC_COMP_RUN;
2809 /* I am proposing to what he should send */
2810 ppp->rstate &= ~SC_DECOMP_RUN;
2817 * CCP is going down, both directions of transmission
2819 ppp->rstate &= ~SC_DECOMP_RUN;
2820 ppp->xstate &= ~SC_COMP_RUN;
2824 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2826 len = CCP_LENGTH(dp);
2827 if (!pskb_may_pull(skb, len + 2))
2828 return; /* too short */
2831 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2834 /* we will start receiving compressed packets */
2837 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2838 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2839 ppp->rstate |= SC_DECOMP_RUN;
2840 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2843 /* we will soon start sending compressed packets */
2846 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2847 ppp->file.index, 0, ppp->debug))
2848 ppp->xstate |= SC_COMP_RUN;
2853 /* reset the [de]compressor */
2854 if ((ppp->flags & SC_CCP_UP) == 0)
2857 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2858 ppp->rcomp->decomp_reset(ppp->rc_state);
2859 ppp->rstate &= ~SC_DC_ERROR;
2862 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2863 ppp->xcomp->comp_reset(ppp->xc_state);
2869 /* Free up compression resources. */
2871 ppp_ccp_closed(struct ppp *ppp)
2873 void *xstate, *rstate;
2874 struct compressor *xcomp, *rcomp;
2877 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2880 xstate = ppp->xc_state;
2881 ppp->xc_state = NULL;
2884 rstate = ppp->rc_state;
2885 ppp->rc_state = NULL;
2889 xcomp->comp_free(xstate);
2890 module_put(xcomp->owner);
2893 rcomp->decomp_free(rstate);
2894 module_put(rcomp->owner);
2898 /* List of compressors. */
2899 static LIST_HEAD(compressor_list);
2900 static DEFINE_SPINLOCK(compressor_list_lock);
2902 struct compressor_entry {
2903 struct list_head list;
2904 struct compressor *comp;
2907 static struct compressor_entry *
2908 find_comp_entry(int proto)
2910 struct compressor_entry *ce;
2912 list_for_each_entry(ce, &compressor_list, list) {
2913 if (ce->comp->compress_proto == proto)
2919 /* Register a compressor */
2921 ppp_register_compressor(struct compressor *cp)
2923 struct compressor_entry *ce;
2925 spin_lock(&compressor_list_lock);
2927 if (find_comp_entry(cp->compress_proto))
2930 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2935 list_add(&ce->list, &compressor_list);
2937 spin_unlock(&compressor_list_lock);
2941 /* Unregister a compressor */
2943 ppp_unregister_compressor(struct compressor *cp)
2945 struct compressor_entry *ce;
2947 spin_lock(&compressor_list_lock);
2948 ce = find_comp_entry(cp->compress_proto);
2949 if (ce && ce->comp == cp) {
2950 list_del(&ce->list);
2953 spin_unlock(&compressor_list_lock);
2956 /* Find a compressor. */
2957 static struct compressor *
2958 find_compressor(int type)
2960 struct compressor_entry *ce;
2961 struct compressor *cp = NULL;
2963 spin_lock(&compressor_list_lock);
2964 ce = find_comp_entry(type);
2967 if (!try_module_get(cp->owner))
2970 spin_unlock(&compressor_list_lock);
2975 * Miscelleneous stuff.
2979 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2981 struct slcompress *vj = ppp->vj;
2983 memset(st, 0, sizeof(*st));
2984 st->p.ppp_ipackets = ppp->stats64.rx_packets;
2985 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2986 st->p.ppp_ibytes = ppp->stats64.rx_bytes;
2987 st->p.ppp_opackets = ppp->stats64.tx_packets;
2988 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2989 st->p.ppp_obytes = ppp->stats64.tx_bytes;
2992 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2993 st->vj.vjs_compressed = vj->sls_o_compressed;
2994 st->vj.vjs_searches = vj->sls_o_searches;
2995 st->vj.vjs_misses = vj->sls_o_misses;
2996 st->vj.vjs_errorin = vj->sls_i_error;
2997 st->vj.vjs_tossed = vj->sls_i_tossed;
2998 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2999 st->vj.vjs_compressedin = vj->sls_i_compressed;
3003 * Stuff for handling the lists of ppp units and channels
3004 * and for initialization.
3008 * Create a new ppp interface unit. Fails if it can't allocate memory
3009 * or if there is already a unit with the requested number.
3010 * unit == -1 means allocate a new number.
3012 static int ppp_create_interface(struct net *net, struct file *file, int *unit)
3014 struct ppp_config conf = {
3017 .ifname_is_set = false,
3019 struct net_device *dev;
3023 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);
3028 dev_net_set(dev, net);
3029 dev->rtnl_link_ops = &ppp_link_ops;
3033 err = ppp_dev_configure(net, dev, &conf);
3036 ppp = netdev_priv(dev);
3037 *unit = ppp->file.index;
3051 * Initialize a ppp_file structure.
3054 init_ppp_file(struct ppp_file *pf, int kind)
3057 skb_queue_head_init(&pf->xq);
3058 skb_queue_head_init(&pf->rq);
3059 refcount_set(&pf->refcnt, 1);
3060 init_waitqueue_head(&pf->rwait);
3064 * Free the memory used by a ppp unit. This is only called once
3065 * there are no channels connected to the unit and no file structs
3066 * that reference the unit.
3068 static void ppp_destroy_interface(struct ppp *ppp)
3070 atomic_dec(&ppp_unit_count);
3072 if (!ppp->file.dead || ppp->n_channels) {
3073 /* "can't happen" */
3074 netdev_err(ppp->dev, "ppp: destroying ppp struct %p "
3075 "but dead=%d n_channels=%d !\n",
3076 ppp, ppp->file.dead, ppp->n_channels);
3080 ppp_ccp_closed(ppp);
3085 skb_queue_purge(&ppp->file.xq);
3086 skb_queue_purge(&ppp->file.rq);
3087 #ifdef CONFIG_PPP_MULTILINK
3088 skb_queue_purge(&ppp->mrq);
3089 #endif /* CONFIG_PPP_MULTILINK */
3090 #ifdef CONFIG_PPP_FILTER
3091 if (ppp->pass_filter) {
3092 bpf_prog_destroy(ppp->pass_filter);
3093 ppp->pass_filter = NULL;
3096 if (ppp->active_filter) {
3097 bpf_prog_destroy(ppp->active_filter);
3098 ppp->active_filter = NULL;
3100 #endif /* CONFIG_PPP_FILTER */
3102 kfree_skb(ppp->xmit_pending);
3103 free_percpu(ppp->xmit_recursion);
3105 free_netdev(ppp->dev);
3109 * Locate an existing ppp unit.
3110 * The caller should have locked the all_ppp_mutex.
3113 ppp_find_unit(struct ppp_net *pn, int unit)
3115 return unit_find(&pn->units_idr, unit);
3119 * Locate an existing ppp channel.
3120 * The caller should have locked the all_channels_lock.
3121 * First we look in the new_channels list, then in the
3122 * all_channels list. If found in the new_channels list,
3123 * we move it to the all_channels list. This is for speed
3124 * when we have a lot of channels in use.
3126 static struct channel *
3127 ppp_find_channel(struct ppp_net *pn, int unit)
3129 struct channel *pch;
3131 list_for_each_entry(pch, &pn->new_channels, list) {
3132 if (pch->file.index == unit) {
3133 list_move(&pch->list, &pn->all_channels);
3138 list_for_each_entry(pch, &pn->all_channels, list) {
3139 if (pch->file.index == unit)
3147 * Connect a PPP channel to a PPP interface unit.
3150 ppp_connect_channel(struct channel *pch, int unit)
3157 pn = ppp_pernet(pch->chan_net);
3159 mutex_lock(&pn->all_ppp_mutex);
3160 ppp = ppp_find_unit(pn, unit);
3163 write_lock_bh(&pch->upl);
3169 spin_lock_bh(&pch->downl);
3171 /* Don't connect unregistered channels */
3172 spin_unlock_bh(&pch->downl);
3177 spin_unlock_bh(&pch->downl);
3178 if (pch->file.hdrlen > ppp->file.hdrlen)
3179 ppp->file.hdrlen = pch->file.hdrlen;
3180 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
3181 if (hdrlen > ppp->dev->hard_header_len)
3182 ppp->dev->hard_header_len = hdrlen;
3183 list_add_tail(&pch->clist, &ppp->channels);
3186 refcount_inc(&ppp->file.refcnt);
3191 write_unlock_bh(&pch->upl);
3193 mutex_unlock(&pn->all_ppp_mutex);
3198 * Disconnect a channel from its ppp unit.
3201 ppp_disconnect_channel(struct channel *pch)
3206 write_lock_bh(&pch->upl);
3209 write_unlock_bh(&pch->upl);
3211 /* remove it from the ppp unit's list */
3213 list_del(&pch->clist);
3214 if (--ppp->n_channels == 0)
3215 wake_up_interruptible(&ppp->file.rwait);
3217 if (refcount_dec_and_test(&ppp->file.refcnt))
3218 ppp_destroy_interface(ppp);
3225 * Free up the resources used by a ppp channel.
3227 static void ppp_destroy_channel(struct channel *pch)
3229 put_net(pch->chan_net);
3230 pch->chan_net = NULL;
3232 atomic_dec(&channel_count);
3234 if (!pch->file.dead) {
3235 /* "can't happen" */
3236 pr_err("ppp: destroying undead channel %p !\n", pch);
3239 skb_queue_purge(&pch->file.xq);
3240 skb_queue_purge(&pch->file.rq);
3244 static void __exit ppp_cleanup(void)
3246 /* should never happen */
3247 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
3248 pr_err("PPP: removing module but units remain!\n");
3249 rtnl_link_unregister(&ppp_link_ops);
3250 unregister_chrdev(PPP_MAJOR, "ppp");
3251 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
3252 class_destroy(ppp_class);
3253 unregister_pernet_device(&ppp_net_ops);
3257 * Units handling. Caller must protect concurrent access
3258 * by holding all_ppp_mutex
3261 /* associate pointer with specified number */
3262 static int unit_set(struct idr *p, void *ptr, int n)
3266 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL);
3267 if (unit == -ENOSPC)
3272 /* get new free unit number and associate pointer with it */
3273 static int unit_get(struct idr *p, void *ptr, int min)
3275 return idr_alloc(p, ptr, min, 0, GFP_KERNEL);
3278 /* put unit number back to a pool */
3279 static void unit_put(struct idr *p, int n)
3284 /* get pointer associated with the number */
3285 static void *unit_find(struct idr *p, int n)
3287 return idr_find(p, n);
3290 /* Module/initialization stuff */
3292 module_init(ppp_init);
3293 module_exit(ppp_cleanup);
3295 EXPORT_SYMBOL(ppp_register_net_channel);
3296 EXPORT_SYMBOL(ppp_register_channel);
3297 EXPORT_SYMBOL(ppp_unregister_channel);
3298 EXPORT_SYMBOL(ppp_channel_index);
3299 EXPORT_SYMBOL(ppp_unit_number);
3300 EXPORT_SYMBOL(ppp_dev_name);
3301 EXPORT_SYMBOL(ppp_input);
3302 EXPORT_SYMBOL(ppp_input_error);
3303 EXPORT_SYMBOL(ppp_output_wakeup);
3304 EXPORT_SYMBOL(ppp_register_compressor);
3305 EXPORT_SYMBOL(ppp_unregister_compressor);
3306 MODULE_LICENSE("GPL");
3307 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
3308 MODULE_ALIAS_RTNL_LINK("ppp");
3309 MODULE_ALIAS("devname:ppp");