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/if_ppp.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 <net/slhc_vj.h>
50 #include <asm/atomic.h>
52 #include <linux/nsproxy.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
56 #define PPP_VERSION "2.4.2"
59 * Network protocols we support.
61 #define NP_IP 0 /* Internet Protocol V4 */
62 #define NP_IPV6 1 /* Internet Protocol V6 */
63 #define NP_IPX 2 /* IPX protocol */
64 #define NP_AT 3 /* Appletalk protocol */
65 #define NP_MPLS_UC 4 /* MPLS unicast */
66 #define NP_MPLS_MC 5 /* MPLS multicast */
67 #define NUM_NP 6 /* Number of NPs. */
69 #define MPHDRLEN 6 /* multilink protocol header length */
70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
73 * An instance of /dev/ppp can be associated with either a ppp
74 * interface unit or a ppp channel. In both cases, file->private_data
75 * points to one of these.
81 struct sk_buff_head xq; /* pppd transmit queue */
82 struct sk_buff_head rq; /* receive queue for pppd */
83 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
84 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
85 int hdrlen; /* space to leave for headers */
86 int index; /* interface unit / channel number */
87 int dead; /* unit/channel has been shut down */
90 #define PF_TO_X(pf, X) container_of(pf, X, file)
92 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
93 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
96 * Data structure describing one ppp unit.
97 * A ppp unit corresponds to a ppp network interface device
98 * and represents a multilink bundle.
99 * It can have 0 or more ppp channels connected to it.
102 struct ppp_file file; /* stuff for read/write/poll 0 */
103 struct file *owner; /* file that owns this unit 48 */
104 struct list_head channels; /* list of attached channels 4c */
105 int n_channels; /* how many channels are attached 54 */
106 spinlock_t rlock; /* lock for receive side 58 */
107 spinlock_t wlock; /* lock for transmit side 5c */
108 int mru; /* max receive unit 60 */
109 unsigned int flags; /* control bits 64 */
110 unsigned int xstate; /* transmit state bits 68 */
111 unsigned int rstate; /* receive state bits 6c */
112 int debug; /* debug flags 70 */
113 struct slcompress *vj; /* state for VJ header compression */
114 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
115 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
116 struct compressor *xcomp; /* transmit packet compressor 8c */
117 void *xc_state; /* its internal state 90 */
118 struct compressor *rcomp; /* receive decompressor 94 */
119 void *rc_state; /* its internal state 98 */
120 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
121 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
122 struct net_device *dev; /* network interface device a4 */
123 int closing; /* is device closing down? a8 */
124 #ifdef CONFIG_PPP_MULTILINK
125 int nxchan; /* next channel to send something on */
126 u32 nxseq; /* next sequence number to send */
127 int mrru; /* MP: max reconst. receive unit */
128 u32 nextseq; /* MP: seq no of next packet */
129 u32 minseq; /* MP: min of most recent seqnos */
130 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
131 #endif /* CONFIG_PPP_MULTILINK */
132 #ifdef CONFIG_PPP_FILTER
133 struct sock_filter *pass_filter; /* filter for packets to pass */
134 struct sock_filter *active_filter;/* filter for pkts to reset idle */
135 unsigned pass_len, active_len;
136 #endif /* CONFIG_PPP_FILTER */
137 struct net *ppp_net; /* the net we belong to */
141 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
142 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
144 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
145 * Bits in xstate: SC_COMP_RUN
147 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
148 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
149 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
152 * Private data structure for each channel.
153 * This includes the data structure used for multilink.
156 struct ppp_file file; /* stuff for read/write/poll */
157 struct list_head list; /* link in all/new_channels list */
158 struct ppp_channel *chan; /* public channel data structure */
159 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
160 spinlock_t downl; /* protects `chan', file.xq dequeue */
161 struct ppp *ppp; /* ppp unit we're connected to */
162 struct net *chan_net; /* the net channel belongs to */
163 struct list_head clist; /* link in list of channels per unit */
164 rwlock_t upl; /* protects `ppp' */
165 #ifdef CONFIG_PPP_MULTILINK
166 u8 avail; /* flag used in multilink stuff */
167 u8 had_frag; /* >= 1 fragments have been sent */
168 u32 lastseq; /* MP: last sequence # received */
169 int speed; /* speed of the corresponding ppp channel*/
170 #endif /* CONFIG_PPP_MULTILINK */
174 * SMP locking issues:
175 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
176 * list and the ppp.n_channels field, you need to take both locks
177 * before you modify them.
178 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
182 static DEFINE_MUTEX(ppp_mutex);
183 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
184 static atomic_t channel_count = ATOMIC_INIT(0);
186 /* per-net private data for this module */
187 static int ppp_net_id __read_mostly;
189 /* units to ppp mapping */
190 struct idr units_idr;
193 * all_ppp_mutex protects the units_idr mapping.
194 * It also ensures that finding a ppp unit in the units_idr
195 * map and updating its file.refcnt field is atomic.
197 struct mutex all_ppp_mutex;
200 struct list_head all_channels;
201 struct list_head new_channels;
202 int last_channel_index;
205 * all_channels_lock protects all_channels and
206 * last_channel_index, and the atomicity of find
207 * a channel and updating its file.refcnt field.
209 spinlock_t all_channels_lock;
212 /* Get the PPP protocol number from a skb */
213 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
215 /* We limit the length of ppp->file.rq to this (arbitrary) value */
216 #define PPP_MAX_RQLEN 32
219 * Maximum number of multilink fragments queued up.
220 * This has to be large enough to cope with the maximum latency of
221 * the slowest channel relative to the others. Strictly it should
222 * depend on the number of channels and their characteristics.
224 #define PPP_MP_MAX_QLEN 128
226 /* Multilink header bits. */
227 #define B 0x80 /* this fragment begins a packet */
228 #define E 0x40 /* this fragment ends a packet */
230 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
231 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
232 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
235 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
236 struct file *file, unsigned int cmd, unsigned long arg);
237 static void ppp_xmit_process(struct ppp *ppp);
238 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
239 static void ppp_push(struct ppp *ppp);
240 static void ppp_channel_push(struct channel *pch);
241 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
242 struct channel *pch);
243 static void ppp_receive_error(struct ppp *ppp);
244 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
245 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
246 struct sk_buff *skb);
247 #ifdef CONFIG_PPP_MULTILINK
248 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
249 struct channel *pch);
250 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
251 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
252 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
253 #endif /* CONFIG_PPP_MULTILINK */
254 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
255 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
256 static void ppp_ccp_closed(struct ppp *ppp);
257 static struct compressor *find_compressor(int type);
258 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
259 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp);
260 static void init_ppp_file(struct ppp_file *pf, int kind);
261 static void ppp_shutdown_interface(struct ppp *ppp);
262 static void ppp_destroy_interface(struct ppp *ppp);
263 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
264 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit);
265 static int ppp_connect_channel(struct channel *pch, int unit);
266 static int ppp_disconnect_channel(struct channel *pch);
267 static void ppp_destroy_channel(struct channel *pch);
268 static int unit_get(struct idr *p, void *ptr);
269 static int unit_set(struct idr *p, void *ptr, int n);
270 static void unit_put(struct idr *p, int n);
271 static void *unit_find(struct idr *p, int n);
273 static struct class *ppp_class;
275 /* per net-namespace data */
276 static inline struct ppp_net *ppp_pernet(struct net *net)
280 return net_generic(net, ppp_net_id);
283 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
284 static inline int proto_to_npindex(int proto)
303 /* Translates an NP index into a PPP protocol number */
304 static const int npindex_to_proto[NUM_NP] = {
313 /* Translates an ethertype into an NP index */
314 static inline int ethertype_to_npindex(int ethertype)
334 /* Translates an NP index into an ethertype */
335 static const int npindex_to_ethertype[NUM_NP] = {
347 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
348 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
349 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
350 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
351 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
352 ppp_recv_lock(ppp); } while (0)
353 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
354 ppp_xmit_unlock(ppp); } while (0)
357 * /dev/ppp device routines.
358 * The /dev/ppp device is used by pppd to control the ppp unit.
359 * It supports the read, write, ioctl and poll functions.
360 * Open instances of /dev/ppp can be in one of three states:
361 * unattached, attached to a ppp unit, or attached to a ppp channel.
363 static int ppp_open(struct inode *inode, struct file *file)
366 * This could (should?) be enforced by the permissions on /dev/ppp.
368 if (!capable(CAP_NET_ADMIN))
373 static int ppp_release(struct inode *unused, struct file *file)
375 struct ppp_file *pf = file->private_data;
379 file->private_data = NULL;
380 if (pf->kind == INTERFACE) {
382 if (file == ppp->owner)
383 ppp_shutdown_interface(ppp);
385 if (atomic_dec_and_test(&pf->refcnt)) {
388 ppp_destroy_interface(PF_TO_PPP(pf));
391 ppp_destroy_channel(PF_TO_CHANNEL(pf));
399 static ssize_t ppp_read(struct file *file, char __user *buf,
400 size_t count, loff_t *ppos)
402 struct ppp_file *pf = file->private_data;
403 DECLARE_WAITQUEUE(wait, current);
405 struct sk_buff *skb = NULL;
412 add_wait_queue(&pf->rwait, &wait);
414 set_current_state(TASK_INTERRUPTIBLE);
415 skb = skb_dequeue(&pf->rq);
421 if (pf->kind == INTERFACE) {
423 * Return 0 (EOF) on an interface that has no
424 * channels connected, unless it is looping
425 * network traffic (demand mode).
427 struct ppp *ppp = PF_TO_PPP(pf);
428 if (ppp->n_channels == 0 &&
429 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
433 if (file->f_flags & O_NONBLOCK)
436 if (signal_pending(current))
440 set_current_state(TASK_RUNNING);
441 remove_wait_queue(&pf->rwait, &wait);
447 if (skb->len > count)
452 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
462 static ssize_t ppp_write(struct file *file, const char __user *buf,
463 size_t count, loff_t *ppos)
465 struct ppp_file *pf = file->private_data;
472 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
475 skb_reserve(skb, pf->hdrlen);
477 if (copy_from_user(skb_put(skb, count), buf, count)) {
482 skb_queue_tail(&pf->xq, skb);
486 ppp_xmit_process(PF_TO_PPP(pf));
489 ppp_channel_push(PF_TO_CHANNEL(pf));
499 /* No kernel lock - fine */
500 static unsigned int ppp_poll(struct file *file, poll_table *wait)
502 struct ppp_file *pf = file->private_data;
507 poll_wait(file, &pf->rwait, wait);
508 mask = POLLOUT | POLLWRNORM;
509 if (skb_peek(&pf->rq))
510 mask |= POLLIN | POLLRDNORM;
513 else if (pf->kind == INTERFACE) {
514 /* see comment in ppp_read */
515 struct ppp *ppp = PF_TO_PPP(pf);
516 if (ppp->n_channels == 0 &&
517 (ppp->flags & SC_LOOP_TRAFFIC) == 0)
518 mask |= POLLIN | POLLRDNORM;
524 #ifdef CONFIG_PPP_FILTER
525 static int get_filter(void __user *arg, struct sock_filter **p)
527 struct sock_fprog uprog;
528 struct sock_filter *code = NULL;
531 if (copy_from_user(&uprog, arg, sizeof(uprog)))
539 len = uprog.len * sizeof(struct sock_filter);
540 code = memdup_user(uprog.filter, len);
542 return PTR_ERR(code);
544 err = sk_chk_filter(code, uprog.len);
553 #endif /* CONFIG_PPP_FILTER */
555 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
557 struct ppp_file *pf = file->private_data;
559 int err = -EFAULT, val, val2, i;
560 struct ppp_idle idle;
563 struct slcompress *vj;
564 void __user *argp = (void __user *)arg;
565 int __user *p = argp;
568 return ppp_unattached_ioctl(current->nsproxy->net_ns,
571 if (cmd == PPPIOCDETACH) {
573 * We have to be careful here... if the file descriptor
574 * has been dup'd, we could have another process in the
575 * middle of a poll using the same file *, so we had
576 * better not free the interface data structures -
577 * instead we fail the ioctl. Even in this case, we
578 * shut down the interface if we are the owner of it.
579 * Actually, we should get rid of PPPIOCDETACH, userland
580 * (i.e. pppd) could achieve the same effect by closing
581 * this fd and reopening /dev/ppp.
584 mutex_lock(&ppp_mutex);
585 if (pf->kind == INTERFACE) {
587 if (file == ppp->owner)
588 ppp_shutdown_interface(ppp);
590 if (atomic_long_read(&file->f_count) <= 2) {
591 ppp_release(NULL, file);
594 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
595 atomic_long_read(&file->f_count));
596 mutex_unlock(&ppp_mutex);
600 if (pf->kind == CHANNEL) {
602 struct ppp_channel *chan;
604 mutex_lock(&ppp_mutex);
605 pch = PF_TO_CHANNEL(pf);
609 if (get_user(unit, p))
611 err = ppp_connect_channel(pch, unit);
615 err = ppp_disconnect_channel(pch);
619 down_read(&pch->chan_sem);
622 if (chan && chan->ops->ioctl)
623 err = chan->ops->ioctl(chan, cmd, arg);
624 up_read(&pch->chan_sem);
626 mutex_unlock(&ppp_mutex);
630 if (pf->kind != INTERFACE) {
632 printk(KERN_ERR "PPP: not interface or channel??\n");
636 mutex_lock(&ppp_mutex);
640 if (get_user(val, p))
647 if (get_user(val, p))
650 cflags = ppp->flags & ~val;
651 ppp->flags = val & SC_FLAG_BITS;
653 if (cflags & SC_CCP_OPEN)
659 val = ppp->flags | ppp->xstate | ppp->rstate;
660 if (put_user(val, p))
665 case PPPIOCSCOMPRESS:
666 err = ppp_set_compress(ppp, arg);
670 if (put_user(ppp->file.index, p))
676 if (get_user(val, p))
683 if (put_user(ppp->debug, p))
689 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
690 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
691 if (copy_to_user(argp, &idle, sizeof(idle)))
697 if (get_user(val, p))
700 if ((val >> 16) != 0) {
704 vj = slhc_init(val2+1, val+1);
706 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
720 if (copy_from_user(&npi, argp, sizeof(npi)))
722 err = proto_to_npindex(npi.protocol);
726 if (cmd == PPPIOCGNPMODE) {
728 npi.mode = ppp->npmode[i];
729 if (copy_to_user(argp, &npi, sizeof(npi)))
732 ppp->npmode[i] = npi.mode;
733 /* we may be able to transmit more packets now (??) */
734 netif_wake_queue(ppp->dev);
739 #ifdef CONFIG_PPP_FILTER
742 struct sock_filter *code;
743 err = get_filter(argp, &code);
746 kfree(ppp->pass_filter);
747 ppp->pass_filter = code;
756 struct sock_filter *code;
757 err = get_filter(argp, &code);
760 kfree(ppp->active_filter);
761 ppp->active_filter = code;
762 ppp->active_len = err;
768 #endif /* CONFIG_PPP_FILTER */
770 #ifdef CONFIG_PPP_MULTILINK
772 if (get_user(val, p))
776 ppp_recv_unlock(ppp);
779 #endif /* CONFIG_PPP_MULTILINK */
784 mutex_unlock(&ppp_mutex);
788 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
789 struct file *file, unsigned int cmd, unsigned long arg)
791 int unit, err = -EFAULT;
793 struct channel *chan;
795 int __user *p = (int __user *)arg;
797 mutex_lock(&ppp_mutex);
800 /* Create a new ppp unit */
801 if (get_user(unit, p))
803 ppp = ppp_create_interface(net, unit, &err);
806 file->private_data = &ppp->file;
809 if (put_user(ppp->file.index, p))
815 /* Attach to an existing ppp unit */
816 if (get_user(unit, p))
819 pn = ppp_pernet(net);
820 mutex_lock(&pn->all_ppp_mutex);
821 ppp = ppp_find_unit(pn, unit);
823 atomic_inc(&ppp->file.refcnt);
824 file->private_data = &ppp->file;
827 mutex_unlock(&pn->all_ppp_mutex);
831 if (get_user(unit, p))
834 pn = ppp_pernet(net);
835 spin_lock_bh(&pn->all_channels_lock);
836 chan = ppp_find_channel(pn, unit);
838 atomic_inc(&chan->file.refcnt);
839 file->private_data = &chan->file;
842 spin_unlock_bh(&pn->all_channels_lock);
848 mutex_unlock(&ppp_mutex);
852 static const struct file_operations ppp_device_fops = {
853 .owner = THIS_MODULE,
857 .unlocked_ioctl = ppp_ioctl,
859 .release = ppp_release
862 static __net_init int ppp_init_net(struct net *net)
864 struct ppp_net *pn = net_generic(net, ppp_net_id);
866 idr_init(&pn->units_idr);
867 mutex_init(&pn->all_ppp_mutex);
869 INIT_LIST_HEAD(&pn->all_channels);
870 INIT_LIST_HEAD(&pn->new_channels);
872 spin_lock_init(&pn->all_channels_lock);
877 static __net_exit void ppp_exit_net(struct net *net)
879 struct ppp_net *pn = net_generic(net, ppp_net_id);
881 idr_destroy(&pn->units_idr);
884 static struct pernet_operations ppp_net_ops = {
885 .init = ppp_init_net,
886 .exit = ppp_exit_net,
888 .size = sizeof(struct ppp_net),
891 #define PPP_MAJOR 108
893 /* Called at boot time if ppp is compiled into the kernel,
894 or at module load time (from init_module) if compiled as a module. */
895 static int __init ppp_init(void)
899 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
901 err = register_pernet_device(&ppp_net_ops);
903 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
907 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
909 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
913 ppp_class = class_create(THIS_MODULE, "ppp");
914 if (IS_ERR(ppp_class)) {
915 err = PTR_ERR(ppp_class);
919 /* not a big deal if we fail here :-) */
920 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
925 unregister_chrdev(PPP_MAJOR, "ppp");
927 unregister_pernet_device(&ppp_net_ops);
933 * Network interface unit routines.
936 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
938 struct ppp *ppp = netdev_priv(dev);
942 npi = ethertype_to_npindex(ntohs(skb->protocol));
946 /* Drop, accept or reject the packet */
947 switch (ppp->npmode[npi]) {
951 /* it would be nice to have a way to tell the network
952 system to queue this one up for later. */
959 /* Put the 2-byte PPP protocol number on the front,
960 making sure there is room for the address and control fields. */
961 if (skb_cow_head(skb, PPP_HDRLEN))
964 pp = skb_push(skb, 2);
965 proto = npindex_to_proto[npi];
969 netif_stop_queue(dev);
970 skb_queue_tail(&ppp->file.xq, skb);
971 ppp_xmit_process(ppp);
976 ++dev->stats.tx_dropped;
981 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
983 struct ppp *ppp = netdev_priv(dev);
985 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
986 struct ppp_stats stats;
987 struct ppp_comp_stats cstats;
992 ppp_get_stats(ppp, &stats);
993 if (copy_to_user(addr, &stats, sizeof(stats)))
999 memset(&cstats, 0, sizeof(cstats));
1001 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1003 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1004 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1011 if (copy_to_user(addr, vers, strlen(vers) + 1))
1023 static const struct net_device_ops ppp_netdev_ops = {
1024 .ndo_start_xmit = ppp_start_xmit,
1025 .ndo_do_ioctl = ppp_net_ioctl,
1028 static void ppp_setup(struct net_device *dev)
1030 dev->netdev_ops = &ppp_netdev_ops;
1031 dev->hard_header_len = PPP_HDRLEN;
1034 dev->tx_queue_len = 3;
1035 dev->type = ARPHRD_PPP;
1036 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1037 dev->features |= NETIF_F_NETNS_LOCAL;
1038 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1042 * Transmit-side routines.
1046 * Called to do any work queued up on the transmit side
1047 * that can now be done.
1050 ppp_xmit_process(struct ppp *ppp)
1052 struct sk_buff *skb;
1055 if (!ppp->closing) {
1057 while (!ppp->xmit_pending &&
1058 (skb = skb_dequeue(&ppp->file.xq)))
1059 ppp_send_frame(ppp, skb);
1060 /* If there's no work left to do, tell the core net
1061 code that we can accept some more. */
1062 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1063 netif_wake_queue(ppp->dev);
1065 ppp_xmit_unlock(ppp);
1068 static inline struct sk_buff *
1069 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1071 struct sk_buff *new_skb;
1073 int new_skb_size = ppp->dev->mtu +
1074 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1075 int compressor_skb_size = ppp->dev->mtu +
1076 ppp->xcomp->comp_extra + PPP_HDRLEN;
1077 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1079 if (net_ratelimit())
1080 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1083 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1084 skb_reserve(new_skb,
1085 ppp->dev->hard_header_len - PPP_HDRLEN);
1087 /* compressor still expects A/C bytes in hdr */
1088 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1089 new_skb->data, skb->len + 2,
1090 compressor_skb_size);
1091 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1095 skb_pull(skb, 2); /* pull off A/C bytes */
1096 } else if (len == 0) {
1097 /* didn't compress, or CCP not up yet */
1103 * MPPE requires that we do not send unencrypted
1104 * frames. The compressor will return -1 if we
1105 * should drop the frame. We cannot simply test
1106 * the compress_proto because MPPE and MPPC share
1109 if (net_ratelimit())
1110 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1119 * Compress and send a frame.
1120 * The caller should have locked the xmit path,
1121 * and xmit_pending should be 0.
1124 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1126 int proto = PPP_PROTO(skb);
1127 struct sk_buff *new_skb;
1131 if (proto < 0x8000) {
1132 #ifdef CONFIG_PPP_FILTER
1133 /* check if we should pass this packet */
1134 /* the filter instructions are constructed assuming
1135 a four-byte PPP header on each packet */
1136 *skb_push(skb, 2) = 1;
1137 if (ppp->pass_filter &&
1138 sk_run_filter(skb, ppp->pass_filter,
1139 ppp->pass_len) == 0) {
1141 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1145 /* if this packet passes the active filter, record the time */
1146 if (!(ppp->active_filter &&
1147 sk_run_filter(skb, ppp->active_filter,
1148 ppp->active_len) == 0))
1149 ppp->last_xmit = jiffies;
1152 /* for data packets, record the time */
1153 ppp->last_xmit = jiffies;
1154 #endif /* CONFIG_PPP_FILTER */
1157 ++ppp->dev->stats.tx_packets;
1158 ppp->dev->stats.tx_bytes += skb->len - 2;
1162 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1164 /* try to do VJ TCP header compression */
1165 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1168 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1171 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1173 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1174 new_skb->data + 2, &cp,
1175 !(ppp->flags & SC_NO_TCP_CCID));
1176 if (cp == skb->data + 2) {
1177 /* didn't compress */
1180 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1181 proto = PPP_VJC_COMP;
1182 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1184 proto = PPP_VJC_UNCOMP;
1185 cp[0] = skb->data[2];
1189 cp = skb_put(skb, len + 2);
1196 /* peek at outbound CCP frames */
1197 ppp_ccp_peek(ppp, skb, 0);
1201 /* try to do packet compression */
1202 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state &&
1203 proto != PPP_LCP && proto != PPP_CCP) {
1204 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1205 if (net_ratelimit())
1206 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1209 skb = pad_compress_skb(ppp, skb);
1215 * If we are waiting for traffic (demand dialling),
1216 * queue it up for pppd to receive.
1218 if (ppp->flags & SC_LOOP_TRAFFIC) {
1219 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1221 skb_queue_tail(&ppp->file.rq, skb);
1222 wake_up_interruptible(&ppp->file.rwait);
1226 ppp->xmit_pending = skb;
1232 ++ppp->dev->stats.tx_errors;
1236 * Try to send the frame in xmit_pending.
1237 * The caller should have the xmit path locked.
1240 ppp_push(struct ppp *ppp)
1242 struct list_head *list;
1243 struct channel *pch;
1244 struct sk_buff *skb = ppp->xmit_pending;
1249 list = &ppp->channels;
1250 if (list_empty(list)) {
1251 /* nowhere to send the packet, just drop it */
1252 ppp->xmit_pending = NULL;
1257 if ((ppp->flags & SC_MULTILINK) == 0) {
1258 /* not doing multilink: send it down the first channel */
1260 pch = list_entry(list, struct channel, clist);
1262 spin_lock_bh(&pch->downl);
1264 if (pch->chan->ops->start_xmit(pch->chan, skb))
1265 ppp->xmit_pending = NULL;
1267 /* channel got unregistered */
1269 ppp->xmit_pending = NULL;
1271 spin_unlock_bh(&pch->downl);
1275 #ifdef CONFIG_PPP_MULTILINK
1276 /* Multilink: fragment the packet over as many links
1277 as can take the packet at the moment. */
1278 if (!ppp_mp_explode(ppp, skb))
1280 #endif /* CONFIG_PPP_MULTILINK */
1282 ppp->xmit_pending = NULL;
1286 #ifdef CONFIG_PPP_MULTILINK
1288 * Divide a packet to be transmitted into fragments and
1289 * send them out the individual links.
1291 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1294 int i, bits, hdrlen, mtu;
1296 int navail, nfree, nzero;
1300 unsigned char *p, *q;
1301 struct list_head *list;
1302 struct channel *pch;
1303 struct sk_buff *frag;
1304 struct ppp_channel *chan;
1306 totspeed = 0; /*total bitrate of the bundle*/
1307 nfree = 0; /* # channels which have no packet already queued */
1308 navail = 0; /* total # of usable channels (not deregistered) */
1309 nzero = 0; /* number of channels with zero speed associated*/
1310 totfree = 0; /*total # of channels available and
1311 *having no queued packets before
1312 *starting the fragmentation*/
1314 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1316 list_for_each_entry(pch, &ppp->channels, clist) {
1320 pch->speed = pch->chan->speed;
1325 if (skb_queue_empty(&pch->file.xq) ||
1327 if (pch->speed == 0)
1330 totspeed += pch->speed;
1336 if (!pch->had_frag && i < ppp->nxchan)
1342 * Don't start sending this packet unless at least half of
1343 * the channels are free. This gives much better TCP
1344 * performance if we have a lot of channels.
1346 if (nfree == 0 || nfree < navail / 2)
1347 return 0; /* can't take now, leave it in xmit_pending */
1349 /* Do protocol field compression (XXX this should be optional) */
1358 nbigger = len % nfree;
1360 /* skip to the channel after the one we last used
1361 and start at that one */
1362 list = &ppp->channels;
1363 for (i = 0; i < ppp->nxchan; ++i) {
1365 if (list == &ppp->channels) {
1371 /* create a fragment for each channel */
1375 if (list == &ppp->channels) {
1379 pch = list_entry(list, struct channel, clist);
1385 * Skip this channel if it has a fragment pending already and
1386 * we haven't given a fragment to all of the free channels.
1388 if (pch->avail == 1) {
1395 /* check the channel's mtu and whether it is still attached. */
1396 spin_lock_bh(&pch->downl);
1397 if (pch->chan == NULL) {
1398 /* can't use this channel, it's being deregistered */
1399 if (pch->speed == 0)
1402 totspeed -= pch->speed;
1404 spin_unlock_bh(&pch->downl);
1415 *if the channel speed is not set divide
1416 *the packet evenly among the free channels;
1417 *otherwise divide it according to the speed
1418 *of the channel we are going to transmit on
1422 if (pch->speed == 0) {
1429 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1430 ((totspeed*totfree)/pch->speed)) - hdrlen;
1432 flen += ((totfree - nzero)*pch->speed)/totspeed;
1433 nbigger -= ((totfree - nzero)*pch->speed)/
1441 *check if we are on the last channel or
1442 *we exceded the lenght of the data to
1445 if ((nfree <= 0) || (flen > len))
1448 *it is not worth to tx on slow channels:
1449 *in that case from the resulting flen according to the
1450 *above formula will be equal or less than zero.
1451 *Skip the channel in this case
1455 spin_unlock_bh(&pch->downl);
1459 mtu = pch->chan->mtu - hdrlen;
1466 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1469 q = skb_put(frag, flen + hdrlen);
1471 /* make the MP header */
1474 if (ppp->flags & SC_MP_XSHORTSEQ) {
1475 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1479 q[3] = ppp->nxseq >> 16;
1480 q[4] = ppp->nxseq >> 8;
1484 memcpy(q + hdrlen, p, flen);
1486 /* try to send it down the channel */
1488 if (!skb_queue_empty(&pch->file.xq) ||
1489 !chan->ops->start_xmit(chan, frag))
1490 skb_queue_tail(&pch->file.xq, frag);
1496 spin_unlock_bh(&pch->downl);
1503 spin_unlock_bh(&pch->downl);
1505 printk(KERN_ERR "PPP: no memory (fragment)\n");
1506 ++ppp->dev->stats.tx_errors;
1508 return 1; /* abandon the frame */
1510 #endif /* CONFIG_PPP_MULTILINK */
1513 * Try to send data out on a channel.
1516 ppp_channel_push(struct channel *pch)
1518 struct sk_buff *skb;
1521 spin_lock_bh(&pch->downl);
1523 while (!skb_queue_empty(&pch->file.xq)) {
1524 skb = skb_dequeue(&pch->file.xq);
1525 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1526 /* put the packet back and try again later */
1527 skb_queue_head(&pch->file.xq, skb);
1532 /* channel got deregistered */
1533 skb_queue_purge(&pch->file.xq);
1535 spin_unlock_bh(&pch->downl);
1536 /* see if there is anything from the attached unit to be sent */
1537 if (skb_queue_empty(&pch->file.xq)) {
1538 read_lock_bh(&pch->upl);
1541 ppp_xmit_process(ppp);
1542 read_unlock_bh(&pch->upl);
1547 * Receive-side routines.
1550 /* misuse a few fields of the skb for MP reconstruction */
1551 #define sequence priority
1552 #define BEbits cb[0]
1555 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1559 ppp_receive_frame(ppp, skb, pch);
1562 ppp_recv_unlock(ppp);
1566 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1568 struct channel *pch = chan->ppp;
1576 read_lock_bh(&pch->upl);
1577 if (!pskb_may_pull(skb, 2)) {
1580 ++pch->ppp->dev->stats.rx_length_errors;
1581 ppp_receive_error(pch->ppp);
1586 proto = PPP_PROTO(skb);
1587 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1588 /* put it on the channel queue */
1589 skb_queue_tail(&pch->file.rq, skb);
1590 /* drop old frames if queue too long */
1591 while (pch->file.rq.qlen > PPP_MAX_RQLEN &&
1592 (skb = skb_dequeue(&pch->file.rq)))
1594 wake_up_interruptible(&pch->file.rwait);
1596 ppp_do_recv(pch->ppp, skb, pch);
1600 read_unlock_bh(&pch->upl);
1603 /* Put a 0-length skb in the receive queue as an error indication */
1605 ppp_input_error(struct ppp_channel *chan, int code)
1607 struct channel *pch = chan->ppp;
1608 struct sk_buff *skb;
1613 read_lock_bh(&pch->upl);
1615 skb = alloc_skb(0, GFP_ATOMIC);
1617 skb->len = 0; /* probably unnecessary */
1619 ppp_do_recv(pch->ppp, skb, pch);
1622 read_unlock_bh(&pch->upl);
1626 * We come in here to process a received frame.
1627 * The receive side of the ppp unit is locked.
1630 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1632 /* note: a 0-length skb is used as an error indication */
1634 #ifdef CONFIG_PPP_MULTILINK
1635 /* XXX do channel-level decompression here */
1636 if (PPP_PROTO(skb) == PPP_MP)
1637 ppp_receive_mp_frame(ppp, skb, pch);
1639 #endif /* CONFIG_PPP_MULTILINK */
1640 ppp_receive_nonmp_frame(ppp, skb);
1643 ppp_receive_error(ppp);
1648 ppp_receive_error(struct ppp *ppp)
1650 ++ppp->dev->stats.rx_errors;
1656 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1659 int proto, len, npi;
1662 * Decompress the frame, if compressed.
1663 * Note that some decompressors need to see uncompressed frames
1664 * that come in as well as compressed frames.
1666 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) &&
1667 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1668 skb = ppp_decompress_frame(ppp, skb);
1670 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1673 proto = PPP_PROTO(skb);
1676 /* decompress VJ compressed packets */
1677 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1680 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1681 /* copy to a new sk_buff with more tailroom */
1682 ns = dev_alloc_skb(skb->len + 128);
1684 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1688 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1693 skb->ip_summed = CHECKSUM_NONE;
1695 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1697 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1702 skb_put(skb, len - skb->len);
1703 else if (len < skb->len)
1708 case PPP_VJC_UNCOMP:
1709 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1712 /* Until we fix the decompressor need to make sure
1713 * data portion is linear.
1715 if (!pskb_may_pull(skb, skb->len))
1718 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1719 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1726 ppp_ccp_peek(ppp, skb, 1);
1730 ++ppp->dev->stats.rx_packets;
1731 ppp->dev->stats.rx_bytes += skb->len - 2;
1733 npi = proto_to_npindex(proto);
1735 /* control or unknown frame - pass it to pppd */
1736 skb_queue_tail(&ppp->file.rq, skb);
1737 /* limit queue length by dropping old frames */
1738 while (ppp->file.rq.qlen > PPP_MAX_RQLEN &&
1739 (skb = skb_dequeue(&ppp->file.rq)))
1741 /* wake up any process polling or blocking on read */
1742 wake_up_interruptible(&ppp->file.rwait);
1745 /* network protocol frame - give it to the kernel */
1747 #ifdef CONFIG_PPP_FILTER
1748 /* check if the packet passes the pass and active filters */
1749 /* the filter instructions are constructed assuming
1750 a four-byte PPP header on each packet */
1751 if (ppp->pass_filter || ppp->active_filter) {
1752 if (skb_cloned(skb) &&
1753 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1756 *skb_push(skb, 2) = 0;
1757 if (ppp->pass_filter &&
1758 sk_run_filter(skb, ppp->pass_filter,
1759 ppp->pass_len) == 0) {
1761 printk(KERN_DEBUG "PPP: inbound frame "
1766 if (!(ppp->active_filter &&
1767 sk_run_filter(skb, ppp->active_filter,
1768 ppp->active_len) == 0))
1769 ppp->last_recv = jiffies;
1772 #endif /* CONFIG_PPP_FILTER */
1773 ppp->last_recv = jiffies;
1775 if ((ppp->dev->flags & IFF_UP) == 0 ||
1776 ppp->npmode[npi] != NPMODE_PASS) {
1779 /* chop off protocol */
1780 skb_pull_rcsum(skb, 2);
1781 skb->dev = ppp->dev;
1782 skb->protocol = htons(npindex_to_ethertype[npi]);
1783 skb_reset_mac_header(skb);
1791 ppp_receive_error(ppp);
1794 static struct sk_buff *
1795 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1797 int proto = PPP_PROTO(skb);
1801 /* Until we fix all the decompressor's need to make sure
1802 * data portion is linear.
1804 if (!pskb_may_pull(skb, skb->len))
1807 if (proto == PPP_COMP) {
1810 switch(ppp->rcomp->compress_proto) {
1812 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1815 obuff_size = ppp->mru + PPP_HDRLEN;
1819 ns = dev_alloc_skb(obuff_size);
1821 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1824 /* the decompressor still expects the A/C bytes in the hdr */
1825 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1826 skb->len + 2, ns->data, obuff_size);
1828 /* Pass the compressed frame to pppd as an
1829 error indication. */
1830 if (len == DECOMP_FATALERROR)
1831 ppp->rstate |= SC_DC_FERROR;
1839 skb_pull(skb, 2); /* pull off the A/C bytes */
1842 /* Uncompressed frame - pass to decompressor so it
1843 can update its dictionary if necessary. */
1844 if (ppp->rcomp->incomp)
1845 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1852 ppp->rstate |= SC_DC_ERROR;
1853 ppp_receive_error(ppp);
1857 #ifdef CONFIG_PPP_MULTILINK
1859 * Receive a multilink frame.
1860 * We put it on the reconstruction queue and then pull off
1861 * as many completed frames as we can.
1864 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1868 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1870 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1871 goto err; /* no good, throw it away */
1873 /* Decode sequence number and begin/end bits */
1874 if (ppp->flags & SC_MP_SHORTSEQ) {
1875 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1878 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1881 skb->BEbits = skb->data[2];
1882 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1885 * Do protocol ID decompression on the first fragment of each packet.
1887 if ((skb->BEbits & B) && (skb->data[0] & 1))
1888 *skb_push(skb, 1) = 0;
1891 * Expand sequence number to 32 bits, making it as close
1892 * as possible to ppp->minseq.
1894 seq |= ppp->minseq & ~mask;
1895 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1897 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1898 seq -= mask + 1; /* should never happen */
1899 skb->sequence = seq;
1903 * If this packet comes before the next one we were expecting,
1906 if (seq_before(seq, ppp->nextseq)) {
1908 ++ppp->dev->stats.rx_dropped;
1909 ppp_receive_error(ppp);
1914 * Reevaluate minseq, the minimum over all channels of the
1915 * last sequence number received on each channel. Because of
1916 * the increasing sequence number rule, we know that any fragment
1917 * before `minseq' which hasn't arrived is never going to arrive.
1918 * The list of channels can't change because we have the receive
1919 * side of the ppp unit locked.
1921 list_for_each_entry(ch, &ppp->channels, clist) {
1922 if (seq_before(ch->lastseq, seq))
1925 if (seq_before(ppp->minseq, seq))
1928 /* Put the fragment on the reconstruction queue */
1929 ppp_mp_insert(ppp, skb);
1931 /* If the queue is getting long, don't wait any longer for packets
1932 before the start of the queue. */
1933 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1934 struct sk_buff *mskb = skb_peek(&ppp->mrq);
1935 if (seq_before(ppp->minseq, mskb->sequence))
1936 ppp->minseq = mskb->sequence;
1939 /* Pull completed packets off the queue and receive them. */
1940 while ((skb = ppp_mp_reconstruct(ppp))) {
1941 if (pskb_may_pull(skb, 2))
1942 ppp_receive_nonmp_frame(ppp, skb);
1944 ++ppp->dev->stats.rx_length_errors;
1946 ppp_receive_error(ppp);
1954 ppp_receive_error(ppp);
1958 * Insert a fragment on the MP reconstruction queue.
1959 * The queue is ordered by increasing sequence number.
1962 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1965 struct sk_buff_head *list = &ppp->mrq;
1966 u32 seq = skb->sequence;
1968 /* N.B. we don't need to lock the list lock because we have the
1969 ppp unit receive-side lock. */
1970 skb_queue_walk(list, p) {
1971 if (seq_before(seq, p->sequence))
1974 __skb_queue_before(list, p, skb);
1978 * Reconstruct a packet from the MP fragment queue.
1979 * We go through increasing sequence numbers until we find a
1980 * complete packet, or we get to the sequence number for a fragment
1981 * which hasn't arrived but might still do so.
1983 static struct sk_buff *
1984 ppp_mp_reconstruct(struct ppp *ppp)
1986 u32 seq = ppp->nextseq;
1987 u32 minseq = ppp->minseq;
1988 struct sk_buff_head *list = &ppp->mrq;
1989 struct sk_buff *p, *next;
1990 struct sk_buff *head, *tail;
1991 struct sk_buff *skb = NULL;
1992 int lost = 0, len = 0;
1994 if (ppp->mrru == 0) /* do nothing until mrru is set */
1998 for (p = head; p != (struct sk_buff *) list; p = next) {
2000 if (seq_before(p->sequence, seq)) {
2001 /* this can't happen, anyway ignore the skb */
2002 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2007 if (p->sequence != seq) {
2008 /* Fragment `seq' is missing. If it is after
2009 minseq, it might arrive later, so stop here. */
2010 if (seq_after(seq, minseq))
2012 /* Fragment `seq' is lost, keep going. */
2014 seq = seq_before(minseq, p->sequence)?
2015 minseq + 1: p->sequence;
2021 * At this point we know that all the fragments from
2022 * ppp->nextseq to seq are either present or lost.
2023 * Also, there are no complete packets in the queue
2024 * that have no missing fragments and end before this
2028 /* B bit set indicates this fragment starts a packet */
2029 if (p->BEbits & B) {
2037 /* Got a complete packet yet? */
2038 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2039 if (len > ppp->mrru + 2) {
2040 ++ppp->dev->stats.rx_length_errors;
2041 printk(KERN_DEBUG "PPP: reconstructed packet"
2042 " is too long (%d)\n", len);
2043 } else if (p == head) {
2044 /* fragment is complete packet - reuse skb */
2048 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2049 ++ppp->dev->stats.rx_missed_errors;
2050 printk(KERN_DEBUG "PPP: no memory for "
2051 "reconstructed packet");
2056 ppp->nextseq = seq + 1;
2060 * If this is the ending fragment of a packet,
2061 * and we haven't found a complete valid packet yet,
2062 * we can discard up to and including this fragment.
2070 /* If we have a complete packet, copy it all into one skb. */
2072 /* If we have discarded any fragments,
2073 signal a receive error. */
2074 if (head->sequence != ppp->nextseq) {
2076 printk(KERN_DEBUG " missed pkts %u..%u\n",
2077 ppp->nextseq, head->sequence-1);
2078 ++ppp->dev->stats.rx_dropped;
2079 ppp_receive_error(ppp);
2083 /* copy to a single skb */
2084 for (p = head; p != tail->next; p = p->next)
2085 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2086 ppp->nextseq = tail->sequence + 1;
2090 /* Discard all the skbuffs that we have copied the data out of
2091 or that we can't use. */
2092 while ((p = list->next) != head) {
2093 __skb_unlink(p, list);
2099 #endif /* CONFIG_PPP_MULTILINK */
2102 * Channel interface.
2105 /* Create a new, unattached ppp channel. */
2106 int ppp_register_channel(struct ppp_channel *chan)
2108 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2111 /* Create a new, unattached ppp channel for specified net. */
2112 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2114 struct channel *pch;
2117 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2121 pn = ppp_pernet(net);
2125 pch->chan_net = net;
2127 init_ppp_file(&pch->file, CHANNEL);
2128 pch->file.hdrlen = chan->hdrlen;
2129 #ifdef CONFIG_PPP_MULTILINK
2131 #endif /* CONFIG_PPP_MULTILINK */
2132 init_rwsem(&pch->chan_sem);
2133 spin_lock_init(&pch->downl);
2134 rwlock_init(&pch->upl);
2136 spin_lock_bh(&pn->all_channels_lock);
2137 pch->file.index = ++pn->last_channel_index;
2138 list_add(&pch->list, &pn->new_channels);
2139 atomic_inc(&channel_count);
2140 spin_unlock_bh(&pn->all_channels_lock);
2146 * Return the index of a channel.
2148 int ppp_channel_index(struct ppp_channel *chan)
2150 struct channel *pch = chan->ppp;
2153 return pch->file.index;
2158 * Return the PPP unit number to which a channel is connected.
2160 int ppp_unit_number(struct ppp_channel *chan)
2162 struct channel *pch = chan->ppp;
2166 read_lock_bh(&pch->upl);
2168 unit = pch->ppp->file.index;
2169 read_unlock_bh(&pch->upl);
2175 * Return the PPP device interface name of a channel.
2177 char *ppp_dev_name(struct ppp_channel *chan)
2179 struct channel *pch = chan->ppp;
2183 read_lock_bh(&pch->upl);
2184 if (pch->ppp && pch->ppp->dev)
2185 name = pch->ppp->dev->name;
2186 read_unlock_bh(&pch->upl);
2193 * Disconnect a channel from the generic layer.
2194 * This must be called in process context.
2197 ppp_unregister_channel(struct ppp_channel *chan)
2199 struct channel *pch = chan->ppp;
2203 return; /* should never happen */
2208 * This ensures that we have returned from any calls into the
2209 * the channel's start_xmit or ioctl routine before we proceed.
2211 down_write(&pch->chan_sem);
2212 spin_lock_bh(&pch->downl);
2214 spin_unlock_bh(&pch->downl);
2215 up_write(&pch->chan_sem);
2216 ppp_disconnect_channel(pch);
2218 pn = ppp_pernet(pch->chan_net);
2219 spin_lock_bh(&pn->all_channels_lock);
2220 list_del(&pch->list);
2221 spin_unlock_bh(&pn->all_channels_lock);
2224 wake_up_interruptible(&pch->file.rwait);
2225 if (atomic_dec_and_test(&pch->file.refcnt))
2226 ppp_destroy_channel(pch);
2230 * Callback from a channel when it can accept more to transmit.
2231 * This should be called at BH/softirq level, not interrupt level.
2234 ppp_output_wakeup(struct ppp_channel *chan)
2236 struct channel *pch = chan->ppp;
2240 ppp_channel_push(pch);
2244 * Compression control.
2247 /* Process the PPPIOCSCOMPRESS ioctl. */
2249 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2252 struct compressor *cp, *ocomp;
2253 struct ppp_option_data data;
2254 void *state, *ostate;
2255 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2258 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) ||
2259 (data.length <= CCP_MAX_OPTION_LENGTH &&
2260 copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2263 if (data.length > CCP_MAX_OPTION_LENGTH ||
2264 ccp_option[1] < 2 || ccp_option[1] > data.length)
2267 cp = try_then_request_module(
2268 find_compressor(ccp_option[0]),
2269 "ppp-compress-%d", ccp_option[0]);
2274 if (data.transmit) {
2275 state = cp->comp_alloc(ccp_option, data.length);
2278 ppp->xstate &= ~SC_COMP_RUN;
2280 ostate = ppp->xc_state;
2282 ppp->xc_state = state;
2283 ppp_xmit_unlock(ppp);
2285 ocomp->comp_free(ostate);
2286 module_put(ocomp->owner);
2290 module_put(cp->owner);
2293 state = cp->decomp_alloc(ccp_option, data.length);
2296 ppp->rstate &= ~SC_DECOMP_RUN;
2298 ostate = ppp->rc_state;
2300 ppp->rc_state = state;
2301 ppp_recv_unlock(ppp);
2303 ocomp->decomp_free(ostate);
2304 module_put(ocomp->owner);
2308 module_put(cp->owner);
2316 * Look at a CCP packet and update our state accordingly.
2317 * We assume the caller has the xmit or recv path locked.
2320 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2325 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2326 return; /* no header */
2329 switch (CCP_CODE(dp)) {
2332 /* A ConfReq starts negotiation of compression
2333 * in one direction of transmission,
2334 * and hence brings it down...but which way?
2337 * A ConfReq indicates what the sender would like to receive
2340 /* He is proposing what I should send */
2341 ppp->xstate &= ~SC_COMP_RUN;
2343 /* I am proposing to what he should send */
2344 ppp->rstate &= ~SC_DECOMP_RUN;
2351 * CCP is going down, both directions of transmission
2353 ppp->rstate &= ~SC_DECOMP_RUN;
2354 ppp->xstate &= ~SC_COMP_RUN;
2358 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2360 len = CCP_LENGTH(dp);
2361 if (!pskb_may_pull(skb, len + 2))
2362 return; /* too short */
2365 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2368 /* we will start receiving compressed packets */
2371 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2372 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2373 ppp->rstate |= SC_DECOMP_RUN;
2374 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2377 /* we will soon start sending compressed packets */
2380 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2381 ppp->file.index, 0, ppp->debug))
2382 ppp->xstate |= SC_COMP_RUN;
2387 /* reset the [de]compressor */
2388 if ((ppp->flags & SC_CCP_UP) == 0)
2391 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2392 ppp->rcomp->decomp_reset(ppp->rc_state);
2393 ppp->rstate &= ~SC_DC_ERROR;
2396 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2397 ppp->xcomp->comp_reset(ppp->xc_state);
2403 /* Free up compression resources. */
2405 ppp_ccp_closed(struct ppp *ppp)
2407 void *xstate, *rstate;
2408 struct compressor *xcomp, *rcomp;
2411 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2414 xstate = ppp->xc_state;
2415 ppp->xc_state = NULL;
2418 rstate = ppp->rc_state;
2419 ppp->rc_state = NULL;
2423 xcomp->comp_free(xstate);
2424 module_put(xcomp->owner);
2427 rcomp->decomp_free(rstate);
2428 module_put(rcomp->owner);
2432 /* List of compressors. */
2433 static LIST_HEAD(compressor_list);
2434 static DEFINE_SPINLOCK(compressor_list_lock);
2436 struct compressor_entry {
2437 struct list_head list;
2438 struct compressor *comp;
2441 static struct compressor_entry *
2442 find_comp_entry(int proto)
2444 struct compressor_entry *ce;
2446 list_for_each_entry(ce, &compressor_list, list) {
2447 if (ce->comp->compress_proto == proto)
2453 /* Register a compressor */
2455 ppp_register_compressor(struct compressor *cp)
2457 struct compressor_entry *ce;
2459 spin_lock(&compressor_list_lock);
2461 if (find_comp_entry(cp->compress_proto))
2464 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2469 list_add(&ce->list, &compressor_list);
2471 spin_unlock(&compressor_list_lock);
2475 /* Unregister a compressor */
2477 ppp_unregister_compressor(struct compressor *cp)
2479 struct compressor_entry *ce;
2481 spin_lock(&compressor_list_lock);
2482 ce = find_comp_entry(cp->compress_proto);
2483 if (ce && ce->comp == cp) {
2484 list_del(&ce->list);
2487 spin_unlock(&compressor_list_lock);
2490 /* Find a compressor. */
2491 static struct compressor *
2492 find_compressor(int type)
2494 struct compressor_entry *ce;
2495 struct compressor *cp = NULL;
2497 spin_lock(&compressor_list_lock);
2498 ce = find_comp_entry(type);
2501 if (!try_module_get(cp->owner))
2504 spin_unlock(&compressor_list_lock);
2509 * Miscelleneous stuff.
2513 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2515 struct slcompress *vj = ppp->vj;
2517 memset(st, 0, sizeof(*st));
2518 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2519 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2520 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2521 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2522 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2523 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2526 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2527 st->vj.vjs_compressed = vj->sls_o_compressed;
2528 st->vj.vjs_searches = vj->sls_o_searches;
2529 st->vj.vjs_misses = vj->sls_o_misses;
2530 st->vj.vjs_errorin = vj->sls_i_error;
2531 st->vj.vjs_tossed = vj->sls_i_tossed;
2532 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2533 st->vj.vjs_compressedin = vj->sls_i_compressed;
2537 * Stuff for handling the lists of ppp units and channels
2538 * and for initialization.
2542 * Create a new ppp interface unit. Fails if it can't allocate memory
2543 * or if there is already a unit with the requested number.
2544 * unit == -1 means allocate a new number.
2547 ppp_create_interface(struct net *net, int unit, int *retp)
2551 struct net_device *dev = NULL;
2555 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2559 pn = ppp_pernet(net);
2561 ppp = netdev_priv(dev);
2564 init_ppp_file(&ppp->file, INTERFACE);
2565 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2566 for (i = 0; i < NUM_NP; ++i)
2567 ppp->npmode[i] = NPMODE_PASS;
2568 INIT_LIST_HEAD(&ppp->channels);
2569 spin_lock_init(&ppp->rlock);
2570 spin_lock_init(&ppp->wlock);
2571 #ifdef CONFIG_PPP_MULTILINK
2573 skb_queue_head_init(&ppp->mrq);
2574 #endif /* CONFIG_PPP_MULTILINK */
2577 * drum roll: don't forget to set
2578 * the net device is belong to
2580 dev_net_set(dev, net);
2583 mutex_lock(&pn->all_ppp_mutex);
2586 unit = unit_get(&pn->units_idr, ppp);
2592 if (unit_find(&pn->units_idr, unit))
2593 goto out2; /* unit already exists */
2595 * if caller need a specified unit number
2596 * lets try to satisfy him, otherwise --
2597 * he should better ask us for new unit number
2599 * NOTE: yes I know that returning EEXIST it's not
2600 * fair but at least pppd will ask us to allocate
2601 * new unit in this case so user is happy :)
2603 unit = unit_set(&pn->units_idr, ppp, unit);
2608 /* Initialize the new ppp unit */
2609 ppp->file.index = unit;
2610 sprintf(dev->name, "ppp%d", unit);
2612 ret = register_netdev(dev);
2614 unit_put(&pn->units_idr, unit);
2615 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2622 atomic_inc(&ppp_unit_count);
2623 mutex_unlock(&pn->all_ppp_mutex);
2629 mutex_unlock(&pn->all_ppp_mutex);
2637 * Initialize a ppp_file structure.
2640 init_ppp_file(struct ppp_file *pf, int kind)
2643 skb_queue_head_init(&pf->xq);
2644 skb_queue_head_init(&pf->rq);
2645 atomic_set(&pf->refcnt, 1);
2646 init_waitqueue_head(&pf->rwait);
2650 * Take down a ppp interface unit - called when the owning file
2651 * (the one that created the unit) is closed or detached.
2653 static void ppp_shutdown_interface(struct ppp *ppp)
2657 pn = ppp_pernet(ppp->ppp_net);
2658 mutex_lock(&pn->all_ppp_mutex);
2660 /* This will call dev_close() for us. */
2662 if (!ppp->closing) {
2665 unregister_netdev(ppp->dev);
2669 unit_put(&pn->units_idr, ppp->file.index);
2672 wake_up_interruptible(&ppp->file.rwait);
2674 mutex_unlock(&pn->all_ppp_mutex);
2678 * Free the memory used by a ppp unit. This is only called once
2679 * there are no channels connected to the unit and no file structs
2680 * that reference the unit.
2682 static void ppp_destroy_interface(struct ppp *ppp)
2684 atomic_dec(&ppp_unit_count);
2686 if (!ppp->file.dead || ppp->n_channels) {
2687 /* "can't happen" */
2688 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2689 "n_channels=%d !\n", ppp, ppp->file.dead,
2694 ppp_ccp_closed(ppp);
2699 skb_queue_purge(&ppp->file.xq);
2700 skb_queue_purge(&ppp->file.rq);
2701 #ifdef CONFIG_PPP_MULTILINK
2702 skb_queue_purge(&ppp->mrq);
2703 #endif /* CONFIG_PPP_MULTILINK */
2704 #ifdef CONFIG_PPP_FILTER
2705 kfree(ppp->pass_filter);
2706 ppp->pass_filter = NULL;
2707 kfree(ppp->active_filter);
2708 ppp->active_filter = NULL;
2709 #endif /* CONFIG_PPP_FILTER */
2711 kfree_skb(ppp->xmit_pending);
2713 free_netdev(ppp->dev);
2717 * Locate an existing ppp unit.
2718 * The caller should have locked the all_ppp_mutex.
2721 ppp_find_unit(struct ppp_net *pn, int unit)
2723 return unit_find(&pn->units_idr, unit);
2727 * Locate an existing ppp channel.
2728 * The caller should have locked the all_channels_lock.
2729 * First we look in the new_channels list, then in the
2730 * all_channels list. If found in the new_channels list,
2731 * we move it to the all_channels list. This is for speed
2732 * when we have a lot of channels in use.
2734 static struct channel *
2735 ppp_find_channel(struct ppp_net *pn, int unit)
2737 struct channel *pch;
2739 list_for_each_entry(pch, &pn->new_channels, list) {
2740 if (pch->file.index == unit) {
2741 list_move(&pch->list, &pn->all_channels);
2746 list_for_each_entry(pch, &pn->all_channels, list) {
2747 if (pch->file.index == unit)
2755 * Connect a PPP channel to a PPP interface unit.
2758 ppp_connect_channel(struct channel *pch, int unit)
2765 pn = ppp_pernet(pch->chan_net);
2767 mutex_lock(&pn->all_ppp_mutex);
2768 ppp = ppp_find_unit(pn, unit);
2771 write_lock_bh(&pch->upl);
2777 if (pch->file.hdrlen > ppp->file.hdrlen)
2778 ppp->file.hdrlen = pch->file.hdrlen;
2779 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2780 if (hdrlen > ppp->dev->hard_header_len)
2781 ppp->dev->hard_header_len = hdrlen;
2782 list_add_tail(&pch->clist, &ppp->channels);
2785 atomic_inc(&ppp->file.refcnt);
2790 write_unlock_bh(&pch->upl);
2792 mutex_unlock(&pn->all_ppp_mutex);
2797 * Disconnect a channel from its ppp unit.
2800 ppp_disconnect_channel(struct channel *pch)
2805 write_lock_bh(&pch->upl);
2808 write_unlock_bh(&pch->upl);
2810 /* remove it from the ppp unit's list */
2812 list_del(&pch->clist);
2813 if (--ppp->n_channels == 0)
2814 wake_up_interruptible(&ppp->file.rwait);
2816 if (atomic_dec_and_test(&ppp->file.refcnt))
2817 ppp_destroy_interface(ppp);
2824 * Free up the resources used by a ppp channel.
2826 static void ppp_destroy_channel(struct channel *pch)
2828 atomic_dec(&channel_count);
2830 if (!pch->file.dead) {
2831 /* "can't happen" */
2832 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2836 skb_queue_purge(&pch->file.xq);
2837 skb_queue_purge(&pch->file.rq);
2841 static void __exit ppp_cleanup(void)
2843 /* should never happen */
2844 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2845 printk(KERN_ERR "PPP: removing module but units remain!\n");
2846 unregister_chrdev(PPP_MAJOR, "ppp");
2847 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2848 class_destroy(ppp_class);
2849 unregister_pernet_device(&ppp_net_ops);
2853 * Units handling. Caller must protect concurrent access
2854 * by holding all_ppp_mutex
2857 /* associate pointer with specified number */
2858 static int unit_set(struct idr *p, void *ptr, int n)
2863 if (!idr_pre_get(p, GFP_KERNEL)) {
2864 printk(KERN_ERR "PPP: No free memory for idr\n");
2868 err = idr_get_new_above(p, ptr, n, &unit);
2873 idr_remove(p, unit);
2880 /* get new free unit number and associate pointer with it */
2881 static int unit_get(struct idr *p, void *ptr)
2886 if (!idr_pre_get(p, GFP_KERNEL)) {
2887 printk(KERN_ERR "PPP: No free memory for idr\n");
2891 err = idr_get_new_above(p, ptr, 0, &unit);
2898 /* put unit number back to a pool */
2899 static void unit_put(struct idr *p, int n)
2904 /* get pointer associated with the number */
2905 static void *unit_find(struct idr *p, int n)
2907 return idr_find(p, n);
2910 /* Module/initialization stuff */
2912 module_init(ppp_init);
2913 module_exit(ppp_cleanup);
2915 EXPORT_SYMBOL(ppp_register_net_channel);
2916 EXPORT_SYMBOL(ppp_register_channel);
2917 EXPORT_SYMBOL(ppp_unregister_channel);
2918 EXPORT_SYMBOL(ppp_channel_index);
2919 EXPORT_SYMBOL(ppp_unit_number);
2920 EXPORT_SYMBOL(ppp_dev_name);
2921 EXPORT_SYMBOL(ppp_input);
2922 EXPORT_SYMBOL(ppp_input_error);
2923 EXPORT_SYMBOL(ppp_output_wakeup);
2924 EXPORT_SYMBOL(ppp_register_compressor);
2925 EXPORT_SYMBOL(ppp_unregister_compressor);
2926 MODULE_LICENSE("GPL");
2927 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
2928 MODULE_ALIAS("devname:ppp");