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/smp_lock.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 <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 */
71 #define MIN_FRAG_SIZE 64
74 * An instance of /dev/ppp can be associated with either a ppp
75 * interface unit or a ppp channel. In both cases, file->private_data
76 * points to one of these.
82 struct sk_buff_head xq; /* pppd transmit queue */
83 struct sk_buff_head rq; /* receive queue for pppd */
84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
86 int hdrlen; /* space to leave for headers */
87 int index; /* interface unit / channel number */
88 int dead; /* unit/channel has been shut down */
91 #define PF_TO_X(pf, X) container_of(pf, X, file)
93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
97 * Data structure describing one ppp unit.
98 * A ppp unit corresponds to a ppp network interface device
99 * and represents a multilink bundle.
100 * It can have 0 or more ppp channels connected to it.
103 struct ppp_file file; /* stuff for read/write/poll 0 */
104 struct file *owner; /* file that owns this unit 48 */
105 struct list_head channels; /* list of attached channels 4c */
106 int n_channels; /* how many channels are attached 54 */
107 spinlock_t rlock; /* lock for receive side 58 */
108 spinlock_t wlock; /* lock for transmit side 5c */
109 int mru; /* max receive unit 60 */
110 unsigned int flags; /* control bits 64 */
111 unsigned int xstate; /* transmit state bits 68 */
112 unsigned int rstate; /* receive state bits 6c */
113 int debug; /* debug flags 70 */
114 struct slcompress *vj; /* state for VJ header compression */
115 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
116 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
117 struct compressor *xcomp; /* transmit packet compressor 8c */
118 void *xc_state; /* its internal state 90 */
119 struct compressor *rcomp; /* receive decompressor 94 */
120 void *rc_state; /* its internal state 98 */
121 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
122 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
123 struct net_device *dev; /* network interface device a4 */
124 int closing; /* is device closing down? a8 */
125 #ifdef CONFIG_PPP_MULTILINK
126 int nxchan; /* next channel to send something on */
127 u32 nxseq; /* next sequence number to send */
128 int mrru; /* MP: max reconst. receive unit */
129 u32 nextseq; /* MP: seq no of next packet */
130 u32 minseq; /* MP: min of most recent seqnos */
131 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
132 #endif /* CONFIG_PPP_MULTILINK */
133 #ifdef CONFIG_PPP_FILTER
134 struct sock_filter *pass_filter; /* filter for packets to pass */
135 struct sock_filter *active_filter;/* filter for pkts to reset idle */
136 unsigned pass_len, active_len;
137 #endif /* CONFIG_PPP_FILTER */
138 struct net *ppp_net; /* the net we belong to */
142 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
143 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
145 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
146 * Bits in xstate: SC_COMP_RUN
148 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
149 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
150 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
153 * Private data structure for each channel.
154 * This includes the data structure used for multilink.
157 struct ppp_file file; /* stuff for read/write/poll */
158 struct list_head list; /* link in all/new_channels list */
159 struct ppp_channel *chan; /* public channel data structure */
160 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
161 spinlock_t downl; /* protects `chan', file.xq dequeue */
162 struct ppp *ppp; /* ppp unit we're connected to */
163 struct net *chan_net; /* the net channel belongs to */
164 struct list_head clist; /* link in list of channels per unit */
165 rwlock_t upl; /* protects `ppp' */
166 #ifdef CONFIG_PPP_MULTILINK
167 u8 avail; /* flag used in multilink stuff */
168 u8 had_frag; /* >= 1 fragments have been sent */
169 u32 lastseq; /* MP: last sequence # received */
170 int speed; /* speed of the corresponding ppp channel*/
171 #endif /* CONFIG_PPP_MULTILINK */
175 * SMP locking issues:
176 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
177 * list and the ppp.n_channels field, you need to take both locks
178 * before you modify them.
179 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
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;
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)
367 * This could (should?) be enforced by the permissions on /dev/ppp.
369 if (!capable(CAP_NET_ADMIN))
374 static int ppp_release(struct inode *unused, struct file *file)
376 struct ppp_file *pf = file->private_data;
380 file->private_data = NULL;
381 if (pf->kind == INTERFACE) {
383 if (file == ppp->owner)
384 ppp_shutdown_interface(ppp);
386 if (atomic_dec_and_test(&pf->refcnt)) {
389 ppp_destroy_interface(PF_TO_PPP(pf));
392 ppp_destroy_channel(PF_TO_CHANNEL(pf));
400 static ssize_t ppp_read(struct file *file, char __user *buf,
401 size_t count, loff_t *ppos)
403 struct ppp_file *pf = file->private_data;
404 DECLARE_WAITQUEUE(wait, current);
406 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)
450 if (copy_to_user(buf, skb->data, skb->len))
460 static ssize_t ppp_write(struct file *file, const char __user *buf,
461 size_t count, loff_t *ppos)
463 struct ppp_file *pf = file->private_data;
470 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
473 skb_reserve(skb, pf->hdrlen);
475 if (copy_from_user(skb_put(skb, count), buf, count)) {
480 skb_queue_tail(&pf->xq, skb);
484 ppp_xmit_process(PF_TO_PPP(pf));
487 ppp_channel_push(PF_TO_CHANNEL(pf));
497 /* No kernel lock - fine */
498 static unsigned int ppp_poll(struct file *file, poll_table *wait)
500 struct ppp_file *pf = file->private_data;
505 poll_wait(file, &pf->rwait, wait);
506 mask = POLLOUT | POLLWRNORM;
507 if (skb_peek(&pf->rq))
508 mask |= POLLIN | POLLRDNORM;
511 else if (pf->kind == INTERFACE) {
512 /* see comment in ppp_read */
513 struct ppp *ppp = PF_TO_PPP(pf);
514 if (ppp->n_channels == 0
515 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
516 mask |= POLLIN | POLLRDNORM;
522 #ifdef CONFIG_PPP_FILTER
523 static int get_filter(void __user *arg, struct sock_filter **p)
525 struct sock_fprog uprog;
526 struct sock_filter *code = NULL;
529 if (copy_from_user(&uprog, arg, sizeof(uprog)))
537 len = uprog.len * sizeof(struct sock_filter);
538 code = kmalloc(len, GFP_KERNEL);
542 if (copy_from_user(code, uprog.filter, len)) {
547 err = sk_chk_filter(code, uprog.len);
556 #endif /* CONFIG_PPP_FILTER */
558 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
560 struct ppp_file *pf = file->private_data;
562 int err = -EFAULT, val, val2, i;
563 struct ppp_idle idle;
566 struct slcompress *vj;
567 void __user *argp = (void __user *)arg;
568 int __user *p = argp;
571 return ppp_unattached_ioctl(current->nsproxy->net_ns,
574 if (cmd == PPPIOCDETACH) {
576 * We have to be careful here... if the file descriptor
577 * has been dup'd, we could have another process in the
578 * middle of a poll using the same file *, so we had
579 * better not free the interface data structures -
580 * instead we fail the ioctl. Even in this case, we
581 * shut down the interface if we are the owner of it.
582 * Actually, we should get rid of PPPIOCDETACH, userland
583 * (i.e. pppd) could achieve the same effect by closing
584 * this fd and reopening /dev/ppp.
588 if (pf->kind == INTERFACE) {
590 if (file == ppp->owner)
591 ppp_shutdown_interface(ppp);
593 if (atomic_long_read(&file->f_count) <= 2) {
594 ppp_release(NULL, file);
597 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
598 atomic_long_read(&file->f_count));
603 if (pf->kind == CHANNEL) {
605 struct ppp_channel *chan;
608 pch = PF_TO_CHANNEL(pf);
612 if (get_user(unit, p))
614 err = ppp_connect_channel(pch, unit);
618 err = ppp_disconnect_channel(pch);
622 down_read(&pch->chan_sem);
625 if (chan && chan->ops->ioctl)
626 err = chan->ops->ioctl(chan, cmd, arg);
627 up_read(&pch->chan_sem);
633 if (pf->kind != INTERFACE) {
635 printk(KERN_ERR "PPP: not interface or channel??\n");
643 if (get_user(val, p))
650 if (get_user(val, p))
653 cflags = ppp->flags & ~val;
654 ppp->flags = val & SC_FLAG_BITS;
656 if (cflags & SC_CCP_OPEN)
662 val = ppp->flags | ppp->xstate | ppp->rstate;
663 if (put_user(val, p))
668 case PPPIOCSCOMPRESS:
669 err = ppp_set_compress(ppp, arg);
673 if (put_user(ppp->file.index, p))
679 if (get_user(val, p))
686 if (put_user(ppp->debug, p))
692 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
693 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
694 if (copy_to_user(argp, &idle, sizeof(idle)))
700 if (get_user(val, p))
703 if ((val >> 16) != 0) {
707 vj = slhc_init(val2+1, val+1);
709 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
723 if (copy_from_user(&npi, argp, sizeof(npi)))
725 err = proto_to_npindex(npi.protocol);
729 if (cmd == PPPIOCGNPMODE) {
731 npi.mode = ppp->npmode[i];
732 if (copy_to_user(argp, &npi, sizeof(npi)))
735 ppp->npmode[i] = npi.mode;
736 /* we may be able to transmit more packets now (??) */
737 netif_wake_queue(ppp->dev);
742 #ifdef CONFIG_PPP_FILTER
745 struct sock_filter *code;
746 err = get_filter(argp, &code);
749 kfree(ppp->pass_filter);
750 ppp->pass_filter = code;
759 struct sock_filter *code;
760 err = get_filter(argp, &code);
763 kfree(ppp->active_filter);
764 ppp->active_filter = code;
765 ppp->active_len = err;
771 #endif /* CONFIG_PPP_FILTER */
773 #ifdef CONFIG_PPP_MULTILINK
775 if (get_user(val, p))
779 ppp_recv_unlock(ppp);
782 #endif /* CONFIG_PPP_MULTILINK */
791 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf,
792 struct file *file, unsigned int cmd, unsigned long arg)
794 int unit, err = -EFAULT;
796 struct channel *chan;
798 int __user *p = (int __user *)arg;
803 /* Create a new ppp unit */
804 if (get_user(unit, p))
806 ppp = ppp_create_interface(net, unit, &err);
809 file->private_data = &ppp->file;
812 if (put_user(ppp->file.index, p))
818 /* Attach to an existing ppp unit */
819 if (get_user(unit, p))
822 pn = ppp_pernet(net);
823 mutex_lock(&pn->all_ppp_mutex);
824 ppp = ppp_find_unit(pn, unit);
826 atomic_inc(&ppp->file.refcnt);
827 file->private_data = &ppp->file;
830 mutex_unlock(&pn->all_ppp_mutex);
834 if (get_user(unit, p))
837 pn = ppp_pernet(net);
838 spin_lock_bh(&pn->all_channels_lock);
839 chan = ppp_find_channel(pn, unit);
841 atomic_inc(&chan->file.refcnt);
842 file->private_data = &chan->file;
845 spin_unlock_bh(&pn->all_channels_lock);
855 static const struct file_operations ppp_device_fops = {
856 .owner = THIS_MODULE,
860 .unlocked_ioctl = ppp_ioctl,
862 .release = ppp_release
865 static __net_init int ppp_init_net(struct net *net)
870 pn = kzalloc(sizeof(*pn), GFP_KERNEL);
874 idr_init(&pn->units_idr);
875 mutex_init(&pn->all_ppp_mutex);
877 INIT_LIST_HEAD(&pn->all_channels);
878 INIT_LIST_HEAD(&pn->new_channels);
880 spin_lock_init(&pn->all_channels_lock);
882 err = net_assign_generic(net, ppp_net_id, pn);
891 static __net_exit void ppp_exit_net(struct net *net)
895 pn = net_generic(net, ppp_net_id);
896 idr_destroy(&pn->units_idr);
898 * if someone has cached our net then
899 * further net_generic call will return NULL
901 net_assign_generic(net, ppp_net_id, NULL);
905 static struct pernet_operations ppp_net_ops = {
906 .init = ppp_init_net,
907 .exit = ppp_exit_net,
910 #define PPP_MAJOR 108
912 /* Called at boot time if ppp is compiled into the kernel,
913 or at module load time (from init_module) if compiled as a module. */
914 static int __init ppp_init(void)
918 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
920 err = register_pernet_gen_device(&ppp_net_id, &ppp_net_ops);
922 printk(KERN_ERR "failed to register PPP pernet device (%d)\n", err);
926 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
928 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
932 ppp_class = class_create(THIS_MODULE, "ppp");
933 if (IS_ERR(ppp_class)) {
934 err = PTR_ERR(ppp_class);
938 /* not a big deal if we fail here :-) */
939 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
944 unregister_chrdev(PPP_MAJOR, "ppp");
946 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
952 * Network interface unit routines.
955 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
957 struct ppp *ppp = netdev_priv(dev);
961 npi = ethertype_to_npindex(ntohs(skb->protocol));
965 /* Drop, accept or reject the packet */
966 switch (ppp->npmode[npi]) {
970 /* it would be nice to have a way to tell the network
971 system to queue this one up for later. */
978 /* Put the 2-byte PPP protocol number on the front,
979 making sure there is room for the address and control fields. */
980 if (skb_cow_head(skb, PPP_HDRLEN))
983 pp = skb_push(skb, 2);
984 proto = npindex_to_proto[npi];
988 netif_stop_queue(dev);
989 skb_queue_tail(&ppp->file.xq, skb);
990 ppp_xmit_process(ppp);
995 ++dev->stats.tx_dropped;
1000 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1002 struct ppp *ppp = netdev_priv(dev);
1004 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
1005 struct ppp_stats stats;
1006 struct ppp_comp_stats cstats;
1011 ppp_get_stats(ppp, &stats);
1012 if (copy_to_user(addr, &stats, sizeof(stats)))
1017 case SIOCGPPPCSTATS:
1018 memset(&cstats, 0, sizeof(cstats));
1020 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
1022 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
1023 if (copy_to_user(addr, &cstats, sizeof(cstats)))
1030 if (copy_to_user(addr, vers, strlen(vers) + 1))
1042 static const struct net_device_ops ppp_netdev_ops = {
1043 .ndo_start_xmit = ppp_start_xmit,
1044 .ndo_do_ioctl = ppp_net_ioctl,
1047 static void ppp_setup(struct net_device *dev)
1049 dev->netdev_ops = &ppp_netdev_ops;
1050 dev->hard_header_len = PPP_HDRLEN;
1053 dev->tx_queue_len = 3;
1054 dev->type = ARPHRD_PPP;
1055 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1056 dev->features |= NETIF_F_NETNS_LOCAL;
1057 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1061 * Transmit-side routines.
1065 * Called to do any work queued up on the transmit side
1066 * that can now be done.
1069 ppp_xmit_process(struct ppp *ppp)
1071 struct sk_buff *skb;
1074 if (!ppp->closing) {
1076 while (!ppp->xmit_pending
1077 && (skb = skb_dequeue(&ppp->file.xq)))
1078 ppp_send_frame(ppp, skb);
1079 /* If there's no work left to do, tell the core net
1080 code that we can accept some more. */
1081 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1082 netif_wake_queue(ppp->dev);
1084 ppp_xmit_unlock(ppp);
1087 static inline struct sk_buff *
1088 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1090 struct sk_buff *new_skb;
1092 int new_skb_size = ppp->dev->mtu +
1093 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1094 int compressor_skb_size = ppp->dev->mtu +
1095 ppp->xcomp->comp_extra + PPP_HDRLEN;
1096 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1098 if (net_ratelimit())
1099 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1102 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1103 skb_reserve(new_skb,
1104 ppp->dev->hard_header_len - PPP_HDRLEN);
1106 /* compressor still expects A/C bytes in hdr */
1107 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1108 new_skb->data, skb->len + 2,
1109 compressor_skb_size);
1110 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1114 skb_pull(skb, 2); /* pull off A/C bytes */
1115 } else if (len == 0) {
1116 /* didn't compress, or CCP not up yet */
1122 * MPPE requires that we do not send unencrypted
1123 * frames. The compressor will return -1 if we
1124 * should drop the frame. We cannot simply test
1125 * the compress_proto because MPPE and MPPC share
1128 if (net_ratelimit())
1129 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1138 * Compress and send a frame.
1139 * The caller should have locked the xmit path,
1140 * and xmit_pending should be 0.
1143 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1145 int proto = PPP_PROTO(skb);
1146 struct sk_buff *new_skb;
1150 if (proto < 0x8000) {
1151 #ifdef CONFIG_PPP_FILTER
1152 /* check if we should pass this packet */
1153 /* the filter instructions are constructed assuming
1154 a four-byte PPP header on each packet */
1155 *skb_push(skb, 2) = 1;
1156 if (ppp->pass_filter
1157 && sk_run_filter(skb, ppp->pass_filter,
1158 ppp->pass_len) == 0) {
1160 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1164 /* if this packet passes the active filter, record the time */
1165 if (!(ppp->active_filter
1166 && sk_run_filter(skb, ppp->active_filter,
1167 ppp->active_len) == 0))
1168 ppp->last_xmit = jiffies;
1171 /* for data packets, record the time */
1172 ppp->last_xmit = jiffies;
1173 #endif /* CONFIG_PPP_FILTER */
1176 ++ppp->dev->stats.tx_packets;
1177 ppp->dev->stats.tx_bytes += skb->len - 2;
1181 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1183 /* try to do VJ TCP header compression */
1184 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1187 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1190 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1192 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1193 new_skb->data + 2, &cp,
1194 !(ppp->flags & SC_NO_TCP_CCID));
1195 if (cp == skb->data + 2) {
1196 /* didn't compress */
1199 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1200 proto = PPP_VJC_COMP;
1201 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1203 proto = PPP_VJC_UNCOMP;
1204 cp[0] = skb->data[2];
1208 cp = skb_put(skb, len + 2);
1215 /* peek at outbound CCP frames */
1216 ppp_ccp_peek(ppp, skb, 0);
1220 /* try to do packet compression */
1221 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1222 && proto != PPP_LCP && proto != PPP_CCP) {
1223 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1224 if (net_ratelimit())
1225 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1228 skb = pad_compress_skb(ppp, skb);
1234 * If we are waiting for traffic (demand dialling),
1235 * queue it up for pppd to receive.
1237 if (ppp->flags & SC_LOOP_TRAFFIC) {
1238 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1240 skb_queue_tail(&ppp->file.rq, skb);
1241 wake_up_interruptible(&ppp->file.rwait);
1245 ppp->xmit_pending = skb;
1251 ++ppp->dev->stats.tx_errors;
1255 * Try to send the frame in xmit_pending.
1256 * The caller should have the xmit path locked.
1259 ppp_push(struct ppp *ppp)
1261 struct list_head *list;
1262 struct channel *pch;
1263 struct sk_buff *skb = ppp->xmit_pending;
1268 list = &ppp->channels;
1269 if (list_empty(list)) {
1270 /* nowhere to send the packet, just drop it */
1271 ppp->xmit_pending = NULL;
1276 if ((ppp->flags & SC_MULTILINK) == 0) {
1277 /* not doing multilink: send it down the first channel */
1279 pch = list_entry(list, struct channel, clist);
1281 spin_lock_bh(&pch->downl);
1283 if (pch->chan->ops->start_xmit(pch->chan, skb))
1284 ppp->xmit_pending = NULL;
1286 /* channel got unregistered */
1288 ppp->xmit_pending = NULL;
1290 spin_unlock_bh(&pch->downl);
1294 #ifdef CONFIG_PPP_MULTILINK
1295 /* Multilink: fragment the packet over as many links
1296 as can take the packet at the moment. */
1297 if (!ppp_mp_explode(ppp, skb))
1299 #endif /* CONFIG_PPP_MULTILINK */
1301 ppp->xmit_pending = NULL;
1305 #ifdef CONFIG_PPP_MULTILINK
1307 * Divide a packet to be transmitted into fragments and
1308 * send them out the individual links.
1310 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1313 int i, bits, hdrlen, mtu;
1315 int navail, nfree, nzero;
1319 unsigned char *p, *q;
1320 struct list_head *list;
1321 struct channel *pch;
1322 struct sk_buff *frag;
1323 struct ppp_channel *chan;
1325 totspeed = 0; /*total bitrate of the bundle*/
1326 nfree = 0; /* # channels which have no packet already queued */
1327 navail = 0; /* total # of usable channels (not deregistered) */
1328 nzero = 0; /* number of channels with zero speed associated*/
1329 totfree = 0; /*total # of channels available and
1330 *having no queued packets before
1331 *starting the fragmentation*/
1333 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1335 list_for_each_entry(pch, &ppp->channels, clist) {
1336 navail += pch->avail = (pch->chan != NULL);
1337 pch->speed = pch->chan->speed;
1339 if (skb_queue_empty(&pch->file.xq) ||
1341 if (pch->speed == 0)
1344 totspeed += pch->speed;
1350 if (!pch->had_frag && i < ppp->nxchan)
1356 * Don't start sending this packet unless at least half of
1357 * the channels are free. This gives much better TCP
1358 * performance if we have a lot of channels.
1360 if (nfree == 0 || nfree < navail / 2)
1361 return 0; /* can't take now, leave it in xmit_pending */
1363 /* Do protocol field compression (XXX this should be optional) */
1372 nbigger = len % nfree;
1374 /* skip to the channel after the one we last used
1375 and start at that one */
1376 list = &ppp->channels;
1377 for (i = 0; i < ppp->nxchan; ++i) {
1379 if (list == &ppp->channels) {
1385 /* create a fragment for each channel */
1387 while (nfree > 0 && len > 0) {
1389 if (list == &ppp->channels) {
1393 pch = list_entry(list, struct channel, clist);
1399 * Skip this channel if it has a fragment pending already and
1400 * we haven't given a fragment to all of the free channels.
1402 if (pch->avail == 1) {
1409 /* check the channel's mtu and whether it is still attached. */
1410 spin_lock_bh(&pch->downl);
1411 if (pch->chan == NULL) {
1412 /* can't use this channel, it's being deregistered */
1413 if (pch->speed == 0)
1416 totspeed -= pch->speed;
1418 spin_unlock_bh(&pch->downl);
1429 *if the channel speed is not set divide
1430 *the packet evenly among the free channels;
1431 *otherwise divide it according to the speed
1432 *of the channel we are going to transmit on
1434 if (pch->speed == 0) {
1435 flen = totlen/nfree ;
1441 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
1442 ((totspeed*totfree)/pch->speed)) - hdrlen;
1444 flen += ((totfree - nzero)*pch->speed)/totspeed;
1445 nbigger -= ((totfree - nzero)*pch->speed)/
1452 *check if we are on the last channel or
1453 *we exceded the lenght of the data to
1456 if ((nfree == 0) || (flen > len))
1459 *it is not worth to tx on slow channels:
1460 *in that case from the resulting flen according to the
1461 *above formula will be equal or less than zero.
1462 *Skip the channel in this case
1466 spin_unlock_bh(&pch->downl);
1470 mtu = pch->chan->mtu + 2 - hdrlen;
1477 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1480 q = skb_put(frag, flen + hdrlen);
1482 /* make the MP header */
1485 if (ppp->flags & SC_MP_XSHORTSEQ) {
1486 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1490 q[3] = ppp->nxseq >> 16;
1491 q[4] = ppp->nxseq >> 8;
1495 memcpy(q + hdrlen, p, flen);
1497 /* try to send it down the channel */
1499 if (!skb_queue_empty(&pch->file.xq) ||
1500 !chan->ops->start_xmit(chan, frag))
1501 skb_queue_tail(&pch->file.xq, frag);
1507 spin_unlock_bh(&pch->downl);
1514 spin_unlock_bh(&pch->downl);
1516 printk(KERN_ERR "PPP: no memory (fragment)\n");
1517 ++ppp->dev->stats.tx_errors;
1519 return 1; /* abandon the frame */
1521 #endif /* CONFIG_PPP_MULTILINK */
1524 * Try to send data out on a channel.
1527 ppp_channel_push(struct channel *pch)
1529 struct sk_buff *skb;
1532 spin_lock_bh(&pch->downl);
1534 while (!skb_queue_empty(&pch->file.xq)) {
1535 skb = skb_dequeue(&pch->file.xq);
1536 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1537 /* put the packet back and try again later */
1538 skb_queue_head(&pch->file.xq, skb);
1543 /* channel got deregistered */
1544 skb_queue_purge(&pch->file.xq);
1546 spin_unlock_bh(&pch->downl);
1547 /* see if there is anything from the attached unit to be sent */
1548 if (skb_queue_empty(&pch->file.xq)) {
1549 read_lock_bh(&pch->upl);
1552 ppp_xmit_process(ppp);
1553 read_unlock_bh(&pch->upl);
1558 * Receive-side routines.
1561 /* misuse a few fields of the skb for MP reconstruction */
1562 #define sequence priority
1563 #define BEbits cb[0]
1566 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1570 ppp_receive_frame(ppp, skb, pch);
1573 ppp_recv_unlock(ppp);
1577 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1579 struct channel *pch = chan->ppp;
1582 if (!pch || skb->len == 0) {
1587 proto = PPP_PROTO(skb);
1588 read_lock_bh(&pch->upl);
1589 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1590 /* put it on the channel queue */
1591 skb_queue_tail(&pch->file.rq, skb);
1592 /* drop old frames if queue too long */
1593 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1594 && (skb = skb_dequeue(&pch->file.rq)))
1596 wake_up_interruptible(&pch->file.rwait);
1598 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 if (pskb_may_pull(skb, 2)) {
1633 #ifdef CONFIG_PPP_MULTILINK
1634 /* XXX do channel-level decompression here */
1635 if (PPP_PROTO(skb) == PPP_MP)
1636 ppp_receive_mp_frame(ppp, skb, pch);
1638 #endif /* CONFIG_PPP_MULTILINK */
1639 ppp_receive_nonmp_frame(ppp, skb);
1644 /* note: a 0-length skb is used as an error indication */
1645 ++ppp->dev->stats.rx_length_errors;
1648 ppp_receive_error(ppp);
1652 ppp_receive_error(struct ppp *ppp)
1654 ++ppp->dev->stats.rx_errors;
1660 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1663 int proto, len, npi;
1666 * Decompress the frame, if compressed.
1667 * Note that some decompressors need to see uncompressed frames
1668 * that come in as well as compressed frames.
1670 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1671 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1672 skb = ppp_decompress_frame(ppp, skb);
1674 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1677 proto = PPP_PROTO(skb);
1680 /* decompress VJ compressed packets */
1681 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1684 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1685 /* copy to a new sk_buff with more tailroom */
1686 ns = dev_alloc_skb(skb->len + 128);
1688 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1692 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1697 skb->ip_summed = CHECKSUM_NONE;
1699 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1701 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1706 skb_put(skb, len - skb->len);
1707 else if (len < skb->len)
1712 case PPP_VJC_UNCOMP:
1713 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1716 /* Until we fix the decompressor need to make sure
1717 * data portion is linear.
1719 if (!pskb_may_pull(skb, skb->len))
1722 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1723 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1730 ppp_ccp_peek(ppp, skb, 1);
1734 ++ppp->dev->stats.rx_packets;
1735 ppp->dev->stats.rx_bytes += skb->len - 2;
1737 npi = proto_to_npindex(proto);
1739 /* control or unknown frame - pass it to pppd */
1740 skb_queue_tail(&ppp->file.rq, skb);
1741 /* limit queue length by dropping old frames */
1742 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1743 && (skb = skb_dequeue(&ppp->file.rq)))
1745 /* wake up any process polling or blocking on read */
1746 wake_up_interruptible(&ppp->file.rwait);
1749 /* network protocol frame - give it to the kernel */
1751 #ifdef CONFIG_PPP_FILTER
1752 /* check if the packet passes the pass and active filters */
1753 /* the filter instructions are constructed assuming
1754 a four-byte PPP header on each packet */
1755 if (ppp->pass_filter || ppp->active_filter) {
1756 if (skb_cloned(skb) &&
1757 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1760 *skb_push(skb, 2) = 0;
1761 if (ppp->pass_filter
1762 && sk_run_filter(skb, ppp->pass_filter,
1763 ppp->pass_len) == 0) {
1765 printk(KERN_DEBUG "PPP: inbound frame "
1770 if (!(ppp->active_filter
1771 && sk_run_filter(skb, ppp->active_filter,
1772 ppp->active_len) == 0))
1773 ppp->last_recv = jiffies;
1776 #endif /* CONFIG_PPP_FILTER */
1777 ppp->last_recv = jiffies;
1779 if ((ppp->dev->flags & IFF_UP) == 0
1780 || ppp->npmode[npi] != NPMODE_PASS) {
1783 /* chop off protocol */
1784 skb_pull_rcsum(skb, 2);
1785 skb->dev = ppp->dev;
1786 skb->protocol = htons(npindex_to_ethertype[npi]);
1787 skb_reset_mac_header(skb);
1795 ppp_receive_error(ppp);
1798 static struct sk_buff *
1799 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1801 int proto = PPP_PROTO(skb);
1805 /* Until we fix all the decompressor's need to make sure
1806 * data portion is linear.
1808 if (!pskb_may_pull(skb, skb->len))
1811 if (proto == PPP_COMP) {
1814 switch(ppp->rcomp->compress_proto) {
1816 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1819 obuff_size = ppp->mru + PPP_HDRLEN;
1823 ns = dev_alloc_skb(obuff_size);
1825 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1828 /* the decompressor still expects the A/C bytes in the hdr */
1829 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1830 skb->len + 2, ns->data, obuff_size);
1832 /* Pass the compressed frame to pppd as an
1833 error indication. */
1834 if (len == DECOMP_FATALERROR)
1835 ppp->rstate |= SC_DC_FERROR;
1843 skb_pull(skb, 2); /* pull off the A/C bytes */
1846 /* Uncompressed frame - pass to decompressor so it
1847 can update its dictionary if necessary. */
1848 if (ppp->rcomp->incomp)
1849 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1856 ppp->rstate |= SC_DC_ERROR;
1857 ppp_receive_error(ppp);
1861 #ifdef CONFIG_PPP_MULTILINK
1863 * Receive a multilink frame.
1864 * We put it on the reconstruction queue and then pull off
1865 * as many completed frames as we can.
1868 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1872 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1874 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1875 goto err; /* no good, throw it away */
1877 /* Decode sequence number and begin/end bits */
1878 if (ppp->flags & SC_MP_SHORTSEQ) {
1879 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1882 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1885 skb->BEbits = skb->data[2];
1886 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1889 * Do protocol ID decompression on the first fragment of each packet.
1891 if ((skb->BEbits & B) && (skb->data[0] & 1))
1892 *skb_push(skb, 1) = 0;
1895 * Expand sequence number to 32 bits, making it as close
1896 * as possible to ppp->minseq.
1898 seq |= ppp->minseq & ~mask;
1899 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1901 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1902 seq -= mask + 1; /* should never happen */
1903 skb->sequence = seq;
1907 * If this packet comes before the next one we were expecting,
1910 if (seq_before(seq, ppp->nextseq)) {
1912 ++ppp->dev->stats.rx_dropped;
1913 ppp_receive_error(ppp);
1918 * Reevaluate minseq, the minimum over all channels of the
1919 * last sequence number received on each channel. Because of
1920 * the increasing sequence number rule, we know that any fragment
1921 * before `minseq' which hasn't arrived is never going to arrive.
1922 * The list of channels can't change because we have the receive
1923 * side of the ppp unit locked.
1925 list_for_each_entry(ch, &ppp->channels, clist) {
1926 if (seq_before(ch->lastseq, seq))
1929 if (seq_before(ppp->minseq, seq))
1932 /* Put the fragment on the reconstruction queue */
1933 ppp_mp_insert(ppp, skb);
1935 /* If the queue is getting long, don't wait any longer for packets
1936 before the start of the queue. */
1937 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1938 struct sk_buff *skb = skb_peek(&ppp->mrq);
1939 if (seq_before(ppp->minseq, skb->sequence))
1940 ppp->minseq = skb->sequence;
1943 /* Pull completed packets off the queue and receive them. */
1944 while ((skb = ppp_mp_reconstruct(ppp)))
1945 ppp_receive_nonmp_frame(ppp, skb);
1951 ppp_receive_error(ppp);
1955 * Insert a fragment on the MP reconstruction queue.
1956 * The queue is ordered by increasing sequence number.
1959 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1962 struct sk_buff_head *list = &ppp->mrq;
1963 u32 seq = skb->sequence;
1965 /* N.B. we don't need to lock the list lock because we have the
1966 ppp unit receive-side lock. */
1967 skb_queue_walk(list, p) {
1968 if (seq_before(seq, p->sequence))
1971 __skb_queue_before(list, p, skb);
1975 * Reconstruct a packet from the MP fragment queue.
1976 * We go through increasing sequence numbers until we find a
1977 * complete packet, or we get to the sequence number for a fragment
1978 * which hasn't arrived but might still do so.
1980 static struct sk_buff *
1981 ppp_mp_reconstruct(struct ppp *ppp)
1983 u32 seq = ppp->nextseq;
1984 u32 minseq = ppp->minseq;
1985 struct sk_buff_head *list = &ppp->mrq;
1986 struct sk_buff *p, *next;
1987 struct sk_buff *head, *tail;
1988 struct sk_buff *skb = NULL;
1989 int lost = 0, len = 0;
1991 if (ppp->mrru == 0) /* do nothing until mrru is set */
1995 for (p = head; p != (struct sk_buff *) list; p = next) {
1997 if (seq_before(p->sequence, seq)) {
1998 /* this can't happen, anyway ignore the skb */
1999 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
2004 if (p->sequence != seq) {
2005 /* Fragment `seq' is missing. If it is after
2006 minseq, it might arrive later, so stop here. */
2007 if (seq_after(seq, minseq))
2009 /* Fragment `seq' is lost, keep going. */
2011 seq = seq_before(minseq, p->sequence)?
2012 minseq + 1: p->sequence;
2018 * At this point we know that all the fragments from
2019 * ppp->nextseq to seq are either present or lost.
2020 * Also, there are no complete packets in the queue
2021 * that have no missing fragments and end before this
2025 /* B bit set indicates this fragment starts a packet */
2026 if (p->BEbits & B) {
2034 /* Got a complete packet yet? */
2035 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
2036 if (len > ppp->mrru + 2) {
2037 ++ppp->dev->stats.rx_length_errors;
2038 printk(KERN_DEBUG "PPP: reconstructed packet"
2039 " is too long (%d)\n", len);
2040 } else if (p == head) {
2041 /* fragment is complete packet - reuse skb */
2045 } else if ((skb = dev_alloc_skb(len)) == NULL) {
2046 ++ppp->dev->stats.rx_missed_errors;
2047 printk(KERN_DEBUG "PPP: no memory for "
2048 "reconstructed packet");
2053 ppp->nextseq = seq + 1;
2057 * If this is the ending fragment of a packet,
2058 * and we haven't found a complete valid packet yet,
2059 * we can discard up to and including this fragment.
2067 /* If we have a complete packet, copy it all into one skb. */
2069 /* If we have discarded any fragments,
2070 signal a receive error. */
2071 if (head->sequence != ppp->nextseq) {
2073 printk(KERN_DEBUG " missed pkts %u..%u\n",
2074 ppp->nextseq, head->sequence-1);
2075 ++ppp->dev->stats.rx_dropped;
2076 ppp_receive_error(ppp);
2080 /* copy to a single skb */
2081 for (p = head; p != tail->next; p = p->next)
2082 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
2083 ppp->nextseq = tail->sequence + 1;
2087 /* Discard all the skbuffs that we have copied the data out of
2088 or that we can't use. */
2089 while ((p = list->next) != head) {
2090 __skb_unlink(p, list);
2096 #endif /* CONFIG_PPP_MULTILINK */
2099 * Channel interface.
2102 /* Create a new, unattached ppp channel. */
2103 int ppp_register_channel(struct ppp_channel *chan)
2105 return ppp_register_net_channel(current->nsproxy->net_ns, chan);
2108 /* Create a new, unattached ppp channel for specified net. */
2109 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan)
2111 struct channel *pch;
2114 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2118 pn = ppp_pernet(net);
2122 pch->chan_net = net;
2124 init_ppp_file(&pch->file, CHANNEL);
2125 pch->file.hdrlen = chan->hdrlen;
2126 #ifdef CONFIG_PPP_MULTILINK
2128 #endif /* CONFIG_PPP_MULTILINK */
2129 init_rwsem(&pch->chan_sem);
2130 spin_lock_init(&pch->downl);
2131 rwlock_init(&pch->upl);
2133 spin_lock_bh(&pn->all_channels_lock);
2134 pch->file.index = ++pn->last_channel_index;
2135 list_add(&pch->list, &pn->new_channels);
2136 atomic_inc(&channel_count);
2137 spin_unlock_bh(&pn->all_channels_lock);
2143 * Return the index of a channel.
2145 int ppp_channel_index(struct ppp_channel *chan)
2147 struct channel *pch = chan->ppp;
2150 return pch->file.index;
2155 * Return the PPP unit number to which a channel is connected.
2157 int ppp_unit_number(struct ppp_channel *chan)
2159 struct channel *pch = chan->ppp;
2163 read_lock_bh(&pch->upl);
2165 unit = pch->ppp->file.index;
2166 read_unlock_bh(&pch->upl);
2172 * Disconnect a channel from the generic layer.
2173 * This must be called in process context.
2176 ppp_unregister_channel(struct ppp_channel *chan)
2178 struct channel *pch = chan->ppp;
2182 return; /* should never happen */
2187 * This ensures that we have returned from any calls into the
2188 * the channel's start_xmit or ioctl routine before we proceed.
2190 down_write(&pch->chan_sem);
2191 spin_lock_bh(&pch->downl);
2193 spin_unlock_bh(&pch->downl);
2194 up_write(&pch->chan_sem);
2195 ppp_disconnect_channel(pch);
2197 pn = ppp_pernet(pch->chan_net);
2198 spin_lock_bh(&pn->all_channels_lock);
2199 list_del(&pch->list);
2200 spin_unlock_bh(&pn->all_channels_lock);
2203 wake_up_interruptible(&pch->file.rwait);
2204 if (atomic_dec_and_test(&pch->file.refcnt))
2205 ppp_destroy_channel(pch);
2209 * Callback from a channel when it can accept more to transmit.
2210 * This should be called at BH/softirq level, not interrupt level.
2213 ppp_output_wakeup(struct ppp_channel *chan)
2215 struct channel *pch = chan->ppp;
2219 ppp_channel_push(pch);
2223 * Compression control.
2226 /* Process the PPPIOCSCOMPRESS ioctl. */
2228 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2231 struct compressor *cp, *ocomp;
2232 struct ppp_option_data data;
2233 void *state, *ostate;
2234 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2237 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2238 || (data.length <= CCP_MAX_OPTION_LENGTH
2239 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2242 if (data.length > CCP_MAX_OPTION_LENGTH
2243 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2246 cp = try_then_request_module(
2247 find_compressor(ccp_option[0]),
2248 "ppp-compress-%d", ccp_option[0]);
2253 if (data.transmit) {
2254 state = cp->comp_alloc(ccp_option, data.length);
2257 ppp->xstate &= ~SC_COMP_RUN;
2259 ostate = ppp->xc_state;
2261 ppp->xc_state = state;
2262 ppp_xmit_unlock(ppp);
2264 ocomp->comp_free(ostate);
2265 module_put(ocomp->owner);
2269 module_put(cp->owner);
2272 state = cp->decomp_alloc(ccp_option, data.length);
2275 ppp->rstate &= ~SC_DECOMP_RUN;
2277 ostate = ppp->rc_state;
2279 ppp->rc_state = state;
2280 ppp_recv_unlock(ppp);
2282 ocomp->decomp_free(ostate);
2283 module_put(ocomp->owner);
2287 module_put(cp->owner);
2295 * Look at a CCP packet and update our state accordingly.
2296 * We assume the caller has the xmit or recv path locked.
2299 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2304 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2305 return; /* no header */
2308 switch (CCP_CODE(dp)) {
2311 /* A ConfReq starts negotiation of compression
2312 * in one direction of transmission,
2313 * and hence brings it down...but which way?
2316 * A ConfReq indicates what the sender would like to receive
2319 /* He is proposing what I should send */
2320 ppp->xstate &= ~SC_COMP_RUN;
2322 /* I am proposing to what he should send */
2323 ppp->rstate &= ~SC_DECOMP_RUN;
2330 * CCP is going down, both directions of transmission
2332 ppp->rstate &= ~SC_DECOMP_RUN;
2333 ppp->xstate &= ~SC_COMP_RUN;
2337 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2339 len = CCP_LENGTH(dp);
2340 if (!pskb_may_pull(skb, len + 2))
2341 return; /* too short */
2344 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2347 /* we will start receiving compressed packets */
2350 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2351 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2352 ppp->rstate |= SC_DECOMP_RUN;
2353 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2356 /* we will soon start sending compressed packets */
2359 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2360 ppp->file.index, 0, ppp->debug))
2361 ppp->xstate |= SC_COMP_RUN;
2366 /* reset the [de]compressor */
2367 if ((ppp->flags & SC_CCP_UP) == 0)
2370 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2371 ppp->rcomp->decomp_reset(ppp->rc_state);
2372 ppp->rstate &= ~SC_DC_ERROR;
2375 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2376 ppp->xcomp->comp_reset(ppp->xc_state);
2382 /* Free up compression resources. */
2384 ppp_ccp_closed(struct ppp *ppp)
2386 void *xstate, *rstate;
2387 struct compressor *xcomp, *rcomp;
2390 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2393 xstate = ppp->xc_state;
2394 ppp->xc_state = NULL;
2397 rstate = ppp->rc_state;
2398 ppp->rc_state = NULL;
2402 xcomp->comp_free(xstate);
2403 module_put(xcomp->owner);
2406 rcomp->decomp_free(rstate);
2407 module_put(rcomp->owner);
2411 /* List of compressors. */
2412 static LIST_HEAD(compressor_list);
2413 static DEFINE_SPINLOCK(compressor_list_lock);
2415 struct compressor_entry {
2416 struct list_head list;
2417 struct compressor *comp;
2420 static struct compressor_entry *
2421 find_comp_entry(int proto)
2423 struct compressor_entry *ce;
2425 list_for_each_entry(ce, &compressor_list, list) {
2426 if (ce->comp->compress_proto == proto)
2432 /* Register a compressor */
2434 ppp_register_compressor(struct compressor *cp)
2436 struct compressor_entry *ce;
2438 spin_lock(&compressor_list_lock);
2440 if (find_comp_entry(cp->compress_proto))
2443 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2448 list_add(&ce->list, &compressor_list);
2450 spin_unlock(&compressor_list_lock);
2454 /* Unregister a compressor */
2456 ppp_unregister_compressor(struct compressor *cp)
2458 struct compressor_entry *ce;
2460 spin_lock(&compressor_list_lock);
2461 ce = find_comp_entry(cp->compress_proto);
2462 if (ce && ce->comp == cp) {
2463 list_del(&ce->list);
2466 spin_unlock(&compressor_list_lock);
2469 /* Find a compressor. */
2470 static struct compressor *
2471 find_compressor(int type)
2473 struct compressor_entry *ce;
2474 struct compressor *cp = NULL;
2476 spin_lock(&compressor_list_lock);
2477 ce = find_comp_entry(type);
2480 if (!try_module_get(cp->owner))
2483 spin_unlock(&compressor_list_lock);
2488 * Miscelleneous stuff.
2492 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2494 struct slcompress *vj = ppp->vj;
2496 memset(st, 0, sizeof(*st));
2497 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2498 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2499 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2500 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2501 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2502 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2505 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2506 st->vj.vjs_compressed = vj->sls_o_compressed;
2507 st->vj.vjs_searches = vj->sls_o_searches;
2508 st->vj.vjs_misses = vj->sls_o_misses;
2509 st->vj.vjs_errorin = vj->sls_i_error;
2510 st->vj.vjs_tossed = vj->sls_i_tossed;
2511 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2512 st->vj.vjs_compressedin = vj->sls_i_compressed;
2516 * Stuff for handling the lists of ppp units and channels
2517 * and for initialization.
2521 * Create a new ppp interface unit. Fails if it can't allocate memory
2522 * or if there is already a unit with the requested number.
2523 * unit == -1 means allocate a new number.
2526 ppp_create_interface(struct net *net, int unit, int *retp)
2530 struct net_device *dev = NULL;
2534 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2538 pn = ppp_pernet(net);
2540 ppp = netdev_priv(dev);
2543 init_ppp_file(&ppp->file, INTERFACE);
2544 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2545 for (i = 0; i < NUM_NP; ++i)
2546 ppp->npmode[i] = NPMODE_PASS;
2547 INIT_LIST_HEAD(&ppp->channels);
2548 spin_lock_init(&ppp->rlock);
2549 spin_lock_init(&ppp->wlock);
2550 #ifdef CONFIG_PPP_MULTILINK
2552 skb_queue_head_init(&ppp->mrq);
2553 #endif /* CONFIG_PPP_MULTILINK */
2556 * drum roll: don't forget to set
2557 * the net device is belong to
2559 dev_net_set(dev, net);
2562 mutex_lock(&pn->all_ppp_mutex);
2565 unit = unit_get(&pn->units_idr, ppp);
2571 if (unit_find(&pn->units_idr, unit))
2572 goto out2; /* unit already exists */
2574 * if caller need a specified unit number
2575 * lets try to satisfy him, otherwise --
2576 * he should better ask us for new unit number
2578 * NOTE: yes I know that returning EEXIST it's not
2579 * fair but at least pppd will ask us to allocate
2580 * new unit in this case so user is happy :)
2582 unit = unit_set(&pn->units_idr, ppp, unit);
2587 /* Initialize the new ppp unit */
2588 ppp->file.index = unit;
2589 sprintf(dev->name, "ppp%d", unit);
2591 ret = register_netdev(dev);
2593 unit_put(&pn->units_idr, unit);
2594 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2601 atomic_inc(&ppp_unit_count);
2602 mutex_unlock(&pn->all_ppp_mutex);
2608 mutex_unlock(&pn->all_ppp_mutex);
2616 * Initialize a ppp_file structure.
2619 init_ppp_file(struct ppp_file *pf, int kind)
2622 skb_queue_head_init(&pf->xq);
2623 skb_queue_head_init(&pf->rq);
2624 atomic_set(&pf->refcnt, 1);
2625 init_waitqueue_head(&pf->rwait);
2629 * Take down a ppp interface unit - called when the owning file
2630 * (the one that created the unit) is closed or detached.
2632 static void ppp_shutdown_interface(struct ppp *ppp)
2636 pn = ppp_pernet(ppp->ppp_net);
2637 mutex_lock(&pn->all_ppp_mutex);
2639 /* This will call dev_close() for us. */
2641 if (!ppp->closing) {
2644 unregister_netdev(ppp->dev);
2648 unit_put(&pn->units_idr, ppp->file.index);
2651 wake_up_interruptible(&ppp->file.rwait);
2653 mutex_unlock(&pn->all_ppp_mutex);
2657 * Free the memory used by a ppp unit. This is only called once
2658 * there are no channels connected to the unit and no file structs
2659 * that reference the unit.
2661 static void ppp_destroy_interface(struct ppp *ppp)
2663 atomic_dec(&ppp_unit_count);
2665 if (!ppp->file.dead || ppp->n_channels) {
2666 /* "can't happen" */
2667 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2668 "n_channels=%d !\n", ppp, ppp->file.dead,
2673 ppp_ccp_closed(ppp);
2678 skb_queue_purge(&ppp->file.xq);
2679 skb_queue_purge(&ppp->file.rq);
2680 #ifdef CONFIG_PPP_MULTILINK
2681 skb_queue_purge(&ppp->mrq);
2682 #endif /* CONFIG_PPP_MULTILINK */
2683 #ifdef CONFIG_PPP_FILTER
2684 kfree(ppp->pass_filter);
2685 ppp->pass_filter = NULL;
2686 kfree(ppp->active_filter);
2687 ppp->active_filter = NULL;
2688 #endif /* CONFIG_PPP_FILTER */
2690 kfree_skb(ppp->xmit_pending);
2692 free_netdev(ppp->dev);
2696 * Locate an existing ppp unit.
2697 * The caller should have locked the all_ppp_mutex.
2700 ppp_find_unit(struct ppp_net *pn, int unit)
2702 return unit_find(&pn->units_idr, unit);
2706 * Locate an existing ppp channel.
2707 * The caller should have locked the all_channels_lock.
2708 * First we look in the new_channels list, then in the
2709 * all_channels list. If found in the new_channels list,
2710 * we move it to the all_channels list. This is for speed
2711 * when we have a lot of channels in use.
2713 static struct channel *
2714 ppp_find_channel(struct ppp_net *pn, int unit)
2716 struct channel *pch;
2718 list_for_each_entry(pch, &pn->new_channels, list) {
2719 if (pch->file.index == unit) {
2720 list_move(&pch->list, &pn->all_channels);
2725 list_for_each_entry(pch, &pn->all_channels, list) {
2726 if (pch->file.index == unit)
2734 * Connect a PPP channel to a PPP interface unit.
2737 ppp_connect_channel(struct channel *pch, int unit)
2744 pn = ppp_pernet(pch->chan_net);
2746 mutex_lock(&pn->all_ppp_mutex);
2747 ppp = ppp_find_unit(pn, unit);
2750 write_lock_bh(&pch->upl);
2756 if (pch->file.hdrlen > ppp->file.hdrlen)
2757 ppp->file.hdrlen = pch->file.hdrlen;
2758 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2759 if (hdrlen > ppp->dev->hard_header_len)
2760 ppp->dev->hard_header_len = hdrlen;
2761 list_add_tail(&pch->clist, &ppp->channels);
2764 atomic_inc(&ppp->file.refcnt);
2769 write_unlock_bh(&pch->upl);
2771 mutex_unlock(&pn->all_ppp_mutex);
2776 * Disconnect a channel from its ppp unit.
2779 ppp_disconnect_channel(struct channel *pch)
2784 write_lock_bh(&pch->upl);
2787 write_unlock_bh(&pch->upl);
2789 /* remove it from the ppp unit's list */
2791 list_del(&pch->clist);
2792 if (--ppp->n_channels == 0)
2793 wake_up_interruptible(&ppp->file.rwait);
2795 if (atomic_dec_and_test(&ppp->file.refcnt))
2796 ppp_destroy_interface(ppp);
2803 * Free up the resources used by a ppp channel.
2805 static void ppp_destroy_channel(struct channel *pch)
2807 atomic_dec(&channel_count);
2809 if (!pch->file.dead) {
2810 /* "can't happen" */
2811 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2815 skb_queue_purge(&pch->file.xq);
2816 skb_queue_purge(&pch->file.rq);
2820 static void __exit ppp_cleanup(void)
2822 /* should never happen */
2823 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2824 printk(KERN_ERR "PPP: removing module but units remain!\n");
2825 unregister_chrdev(PPP_MAJOR, "ppp");
2826 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2827 class_destroy(ppp_class);
2828 unregister_pernet_gen_device(ppp_net_id, &ppp_net_ops);
2832 * Units handling. Caller must protect concurrent access
2833 * by holding all_ppp_mutex
2836 /* associate pointer with specified number */
2837 static int unit_set(struct idr *p, void *ptr, int n)
2842 if (!idr_pre_get(p, GFP_KERNEL)) {
2843 printk(KERN_ERR "PPP: No free memory for idr\n");
2847 err = idr_get_new_above(p, ptr, n, &unit);
2852 idr_remove(p, unit);
2859 /* get new free unit number and associate pointer with it */
2860 static int unit_get(struct idr *p, void *ptr)
2865 if (!idr_pre_get(p, GFP_KERNEL)) {
2866 printk(KERN_ERR "PPP: No free memory for idr\n");
2870 err = idr_get_new_above(p, ptr, 0, &unit);
2877 /* put unit number back to a pool */
2878 static void unit_put(struct idr *p, int n)
2883 /* get pointer associated with the number */
2884 static void *unit_find(struct idr *p, int n)
2886 return idr_find(p, n);
2889 /* Module/initialization stuff */
2891 module_init(ppp_init);
2892 module_exit(ppp_cleanup);
2894 EXPORT_SYMBOL(ppp_register_net_channel);
2895 EXPORT_SYMBOL(ppp_register_channel);
2896 EXPORT_SYMBOL(ppp_unregister_channel);
2897 EXPORT_SYMBOL(ppp_channel_index);
2898 EXPORT_SYMBOL(ppp_unit_number);
2899 EXPORT_SYMBOL(ppp_input);
2900 EXPORT_SYMBOL(ppp_input_error);
2901 EXPORT_SYMBOL(ppp_output_wakeup);
2902 EXPORT_SYMBOL(ppp_register_compressor);
2903 EXPORT_SYMBOL(ppp_unregister_compressor);
2904 MODULE_LICENSE("GPL");
2905 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2906 MODULE_ALIAS("/dev/ppp");