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 #define PPP_VERSION "2.4.2"
55 * Network protocols we support.
57 #define NP_IP 0 /* Internet Protocol V4 */
58 #define NP_IPV6 1 /* Internet Protocol V6 */
59 #define NP_IPX 2 /* IPX protocol */
60 #define NP_AT 3 /* Appletalk protocol */
61 #define NP_MPLS_UC 4 /* MPLS unicast */
62 #define NP_MPLS_MC 5 /* MPLS multicast */
63 #define NUM_NP 6 /* Number of NPs. */
65 #define MPHDRLEN 6 /* multilink protocol header length */
66 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
67 #define MIN_FRAG_SIZE 64
70 * An instance of /dev/ppp can be associated with either a ppp
71 * interface unit or a ppp channel. In both cases, file->private_data
72 * points to one of these.
78 struct sk_buff_head xq; /* pppd transmit queue */
79 struct sk_buff_head rq; /* receive queue for pppd */
80 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
81 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
82 int hdrlen; /* space to leave for headers */
83 int index; /* interface unit / channel number */
84 int dead; /* unit/channel has been shut down */
87 #define PF_TO_X(pf, X) container_of(pf, X, file)
89 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
90 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
93 * Data structure describing one ppp unit.
94 * A ppp unit corresponds to a ppp network interface device
95 * and represents a multilink bundle.
96 * It can have 0 or more ppp channels connected to it.
99 struct ppp_file file; /* stuff for read/write/poll 0 */
100 struct file *owner; /* file that owns this unit 48 */
101 struct list_head channels; /* list of attached channels 4c */
102 int n_channels; /* how many channels are attached 54 */
103 spinlock_t rlock; /* lock for receive side 58 */
104 spinlock_t wlock; /* lock for transmit side 5c */
105 int mru; /* max receive unit 60 */
106 unsigned int flags; /* control bits 64 */
107 unsigned int xstate; /* transmit state bits 68 */
108 unsigned int rstate; /* receive state bits 6c */
109 int debug; /* debug flags 70 */
110 struct slcompress *vj; /* state for VJ header compression */
111 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
112 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
113 struct compressor *xcomp; /* transmit packet compressor 8c */
114 void *xc_state; /* its internal state 90 */
115 struct compressor *rcomp; /* receive decompressor 94 */
116 void *rc_state; /* its internal state 98 */
117 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
118 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
119 struct net_device *dev; /* network interface device a4 */
120 #ifdef CONFIG_PPP_MULTILINK
121 int nxchan; /* next channel to send something on */
122 u32 nxseq; /* next sequence number to send */
123 int mrru; /* MP: max reconst. receive unit */
124 u32 nextseq; /* MP: seq no of next packet */
125 u32 minseq; /* MP: min of most recent seqnos */
126 struct sk_buff_head mrq; /* MP: receive reconstruction queue */
127 #endif /* CONFIG_PPP_MULTILINK */
128 #ifdef CONFIG_PPP_FILTER
129 struct sock_filter *pass_filter; /* filter for packets to pass */
130 struct sock_filter *active_filter;/* filter for pkts to reset idle */
131 unsigned pass_len, active_len;
132 #endif /* CONFIG_PPP_FILTER */
136 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
137 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
139 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
140 * Bits in xstate: SC_COMP_RUN
142 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
143 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
144 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
147 * Private data structure for each channel.
148 * This includes the data structure used for multilink.
151 struct ppp_file file; /* stuff for read/write/poll */
152 struct list_head list; /* link in all/new_channels list */
153 struct ppp_channel *chan; /* public channel data structure */
154 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
155 spinlock_t downl; /* protects `chan', file.xq dequeue */
156 struct ppp *ppp; /* ppp unit we're connected to */
157 struct list_head clist; /* link in list of channels per unit */
158 rwlock_t upl; /* protects `ppp' */
159 #ifdef CONFIG_PPP_MULTILINK
160 u8 avail; /* flag used in multilink stuff */
161 u8 had_frag; /* >= 1 fragments have been sent */
162 u32 lastseq; /* MP: last sequence # received */
163 #endif /* CONFIG_PPP_MULTILINK */
167 * SMP locking issues:
168 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
169 * list and the ppp.n_channels field, you need to take both locks
170 * before you modify them.
171 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
176 * all_ppp_mutex protects the all_ppp_units mapping.
177 * It also ensures that finding a ppp unit in the all_ppp_units map
178 * and updating its file.refcnt field is atomic.
180 static DEFINE_MUTEX(all_ppp_mutex);
181 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
182 static struct idr ppp_units_idr;
185 * all_channels_lock protects all_channels and last_channel_index,
186 * and the atomicity of find a channel and updating its file.refcnt
189 static DEFINE_SPINLOCK(all_channels_lock);
190 static LIST_HEAD(all_channels);
191 static LIST_HEAD(new_channels);
192 static int last_channel_index;
193 static atomic_t channel_count = ATOMIC_INIT(0);
195 /* Get the PPP protocol number from a skb */
196 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
198 /* We limit the length of ppp->file.rq to this (arbitrary) value */
199 #define PPP_MAX_RQLEN 32
202 * Maximum number of multilink fragments queued up.
203 * This has to be large enough to cope with the maximum latency of
204 * the slowest channel relative to the others. Strictly it should
205 * depend on the number of channels and their characteristics.
207 #define PPP_MP_MAX_QLEN 128
209 /* Multilink header bits. */
210 #define B 0x80 /* this fragment begins a packet */
211 #define E 0x40 /* this fragment ends a packet */
213 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
214 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
215 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
218 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
219 unsigned int cmd, unsigned long arg);
220 static void ppp_xmit_process(struct ppp *ppp);
221 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
222 static void ppp_push(struct ppp *ppp);
223 static void ppp_channel_push(struct channel *pch);
224 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
225 struct channel *pch);
226 static void ppp_receive_error(struct ppp *ppp);
227 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
228 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
229 struct sk_buff *skb);
230 #ifdef CONFIG_PPP_MULTILINK
231 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
232 struct channel *pch);
233 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
234 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
235 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
236 #endif /* CONFIG_PPP_MULTILINK */
237 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
238 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
239 static void ppp_ccp_closed(struct ppp *ppp);
240 static struct compressor *find_compressor(int type);
241 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
242 static struct ppp *ppp_create_interface(int unit, int *retp);
243 static void init_ppp_file(struct ppp_file *pf, int kind);
244 static void ppp_shutdown_interface(struct ppp *ppp);
245 static void ppp_destroy_interface(struct ppp *ppp);
246 static struct ppp *ppp_find_unit(int unit);
247 static struct channel *ppp_find_channel(int unit);
248 static int ppp_connect_channel(struct channel *pch, int unit);
249 static int ppp_disconnect_channel(struct channel *pch);
250 static void ppp_destroy_channel(struct channel *pch);
251 static int unit_get(struct idr *p, void *ptr);
252 static void unit_put(struct idr *p, int n);
253 static void *unit_find(struct idr *p, int n);
255 static struct class *ppp_class;
257 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
258 static inline int proto_to_npindex(int proto)
277 /* Translates an NP index into a PPP protocol number */
278 static const int npindex_to_proto[NUM_NP] = {
287 /* Translates an ethertype into an NP index */
288 static inline int ethertype_to_npindex(int ethertype)
308 /* Translates an NP index into an ethertype */
309 static const int npindex_to_ethertype[NUM_NP] = {
321 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
322 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
323 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
324 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
325 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
326 ppp_recv_lock(ppp); } while (0)
327 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
328 ppp_xmit_unlock(ppp); } while (0)
331 * /dev/ppp device routines.
332 * The /dev/ppp device is used by pppd to control the ppp unit.
333 * It supports the read, write, ioctl and poll functions.
334 * Open instances of /dev/ppp can be in one of three states:
335 * unattached, attached to a ppp unit, or attached to a ppp channel.
337 static int ppp_open(struct inode *inode, struct file *file)
341 * This could (should?) be enforced by the permissions on /dev/ppp.
343 if (!capable(CAP_NET_ADMIN))
348 static int ppp_release(struct inode *unused, struct file *file)
350 struct ppp_file *pf = file->private_data;
354 file->private_data = NULL;
355 if (pf->kind == INTERFACE) {
357 if (file == ppp->owner)
358 ppp_shutdown_interface(ppp);
360 if (atomic_dec_and_test(&pf->refcnt)) {
363 ppp_destroy_interface(PF_TO_PPP(pf));
366 ppp_destroy_channel(PF_TO_CHANNEL(pf));
374 static ssize_t ppp_read(struct file *file, char __user *buf,
375 size_t count, loff_t *ppos)
377 struct ppp_file *pf = file->private_data;
378 DECLARE_WAITQUEUE(wait, current);
380 struct sk_buff *skb = NULL;
386 add_wait_queue(&pf->rwait, &wait);
388 set_current_state(TASK_INTERRUPTIBLE);
389 skb = skb_dequeue(&pf->rq);
395 if (pf->kind == INTERFACE) {
397 * Return 0 (EOF) on an interface that has no
398 * channels connected, unless it is looping
399 * network traffic (demand mode).
401 struct ppp *ppp = PF_TO_PPP(pf);
402 if (ppp->n_channels == 0
403 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
407 if (file->f_flags & O_NONBLOCK)
410 if (signal_pending(current))
414 set_current_state(TASK_RUNNING);
415 remove_wait_queue(&pf->rwait, &wait);
421 if (skb->len > count)
424 if (copy_to_user(buf, skb->data, skb->len))
434 static ssize_t ppp_write(struct file *file, const char __user *buf,
435 size_t count, loff_t *ppos)
437 struct ppp_file *pf = file->private_data;
444 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
447 skb_reserve(skb, pf->hdrlen);
449 if (copy_from_user(skb_put(skb, count), buf, count)) {
454 skb_queue_tail(&pf->xq, skb);
458 ppp_xmit_process(PF_TO_PPP(pf));
461 ppp_channel_push(PF_TO_CHANNEL(pf));
471 /* No kernel lock - fine */
472 static unsigned int ppp_poll(struct file *file, poll_table *wait)
474 struct ppp_file *pf = file->private_data;
479 poll_wait(file, &pf->rwait, wait);
480 mask = POLLOUT | POLLWRNORM;
481 if (skb_peek(&pf->rq))
482 mask |= POLLIN | POLLRDNORM;
485 else if (pf->kind == INTERFACE) {
486 /* see comment in ppp_read */
487 struct ppp *ppp = PF_TO_PPP(pf);
488 if (ppp->n_channels == 0
489 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
490 mask |= POLLIN | POLLRDNORM;
496 #ifdef CONFIG_PPP_FILTER
497 static int get_filter(void __user *arg, struct sock_filter **p)
499 struct sock_fprog uprog;
500 struct sock_filter *code = NULL;
503 if (copy_from_user(&uprog, arg, sizeof(uprog)))
511 len = uprog.len * sizeof(struct sock_filter);
512 code = kmalloc(len, GFP_KERNEL);
516 if (copy_from_user(code, uprog.filter, len)) {
521 err = sk_chk_filter(code, uprog.len);
530 #endif /* CONFIG_PPP_FILTER */
532 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
534 struct ppp_file *pf = file->private_data;
536 int err = -EFAULT, val, val2, i;
537 struct ppp_idle idle;
540 struct slcompress *vj;
541 void __user *argp = (void __user *)arg;
542 int __user *p = argp;
545 return ppp_unattached_ioctl(pf, file, cmd, arg);
547 if (cmd == PPPIOCDETACH) {
549 * We have to be careful here... if the file descriptor
550 * has been dup'd, we could have another process in the
551 * middle of a poll using the same file *, so we had
552 * better not free the interface data structures -
553 * instead we fail the ioctl. Even in this case, we
554 * shut down the interface if we are the owner of it.
555 * Actually, we should get rid of PPPIOCDETACH, userland
556 * (i.e. pppd) could achieve the same effect by closing
557 * this fd and reopening /dev/ppp.
561 if (pf->kind == INTERFACE) {
563 if (file == ppp->owner)
564 ppp_shutdown_interface(ppp);
566 if (atomic_long_read(&file->f_count) <= 2) {
567 ppp_release(NULL, file);
570 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
571 atomic_long_read(&file->f_count));
576 if (pf->kind == CHANNEL) {
578 struct ppp_channel *chan;
581 pch = PF_TO_CHANNEL(pf);
585 if (get_user(unit, p))
587 err = ppp_connect_channel(pch, unit);
591 err = ppp_disconnect_channel(pch);
595 down_read(&pch->chan_sem);
598 if (chan && chan->ops->ioctl)
599 err = chan->ops->ioctl(chan, cmd, arg);
600 up_read(&pch->chan_sem);
606 if (pf->kind != INTERFACE) {
608 printk(KERN_ERR "PPP: not interface or channel??\n");
616 if (get_user(val, p))
623 if (get_user(val, p))
626 cflags = ppp->flags & ~val;
627 ppp->flags = val & SC_FLAG_BITS;
629 if (cflags & SC_CCP_OPEN)
635 val = ppp->flags | ppp->xstate | ppp->rstate;
636 if (put_user(val, p))
641 case PPPIOCSCOMPRESS:
642 err = ppp_set_compress(ppp, arg);
646 if (put_user(ppp->file.index, p))
652 if (get_user(val, p))
659 if (put_user(ppp->debug, p))
665 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
666 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
667 if (copy_to_user(argp, &idle, sizeof(idle)))
673 if (get_user(val, p))
676 if ((val >> 16) != 0) {
680 vj = slhc_init(val2+1, val+1);
682 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
696 if (copy_from_user(&npi, argp, sizeof(npi)))
698 err = proto_to_npindex(npi.protocol);
702 if (cmd == PPPIOCGNPMODE) {
704 npi.mode = ppp->npmode[i];
705 if (copy_to_user(argp, &npi, sizeof(npi)))
708 ppp->npmode[i] = npi.mode;
709 /* we may be able to transmit more packets now (??) */
710 netif_wake_queue(ppp->dev);
715 #ifdef CONFIG_PPP_FILTER
718 struct sock_filter *code;
719 err = get_filter(argp, &code);
722 kfree(ppp->pass_filter);
723 ppp->pass_filter = code;
732 struct sock_filter *code;
733 err = get_filter(argp, &code);
736 kfree(ppp->active_filter);
737 ppp->active_filter = code;
738 ppp->active_len = err;
744 #endif /* CONFIG_PPP_FILTER */
746 #ifdef CONFIG_PPP_MULTILINK
748 if (get_user(val, p))
752 ppp_recv_unlock(ppp);
755 #endif /* CONFIG_PPP_MULTILINK */
764 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
765 unsigned int cmd, unsigned long arg)
767 int unit, err = -EFAULT;
769 struct channel *chan;
770 int __user *p = (int __user *)arg;
775 /* Create a new ppp unit */
776 if (get_user(unit, p))
778 ppp = ppp_create_interface(unit, &err);
781 file->private_data = &ppp->file;
784 if (put_user(ppp->file.index, p))
790 /* Attach to an existing ppp unit */
791 if (get_user(unit, p))
793 mutex_lock(&all_ppp_mutex);
795 ppp = ppp_find_unit(unit);
797 atomic_inc(&ppp->file.refcnt);
798 file->private_data = &ppp->file;
801 mutex_unlock(&all_ppp_mutex);
805 if (get_user(unit, p))
807 spin_lock_bh(&all_channels_lock);
809 chan = ppp_find_channel(unit);
811 atomic_inc(&chan->file.refcnt);
812 file->private_data = &chan->file;
815 spin_unlock_bh(&all_channels_lock);
825 static const struct file_operations ppp_device_fops = {
826 .owner = THIS_MODULE,
830 .unlocked_ioctl = ppp_ioctl,
832 .release = ppp_release
835 #define PPP_MAJOR 108
837 /* Called at boot time if ppp is compiled into the kernel,
838 or at module load time (from init_module) if compiled as a module. */
839 static int __init ppp_init(void)
843 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
844 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
846 ppp_class = class_create(THIS_MODULE, "ppp");
847 if (IS_ERR(ppp_class)) {
848 err = PTR_ERR(ppp_class);
851 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
855 idr_init(&ppp_units_idr);
859 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
863 unregister_chrdev(PPP_MAJOR, "ppp");
868 * Network interface unit routines.
871 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
873 struct ppp *ppp = netdev_priv(dev);
877 npi = ethertype_to_npindex(ntohs(skb->protocol));
881 /* Drop, accept or reject the packet */
882 switch (ppp->npmode[npi]) {
886 /* it would be nice to have a way to tell the network
887 system to queue this one up for later. */
894 /* Put the 2-byte PPP protocol number on the front,
895 making sure there is room for the address and control fields. */
896 if (skb_cow_head(skb, PPP_HDRLEN))
899 pp = skb_push(skb, 2);
900 proto = npindex_to_proto[npi];
904 netif_stop_queue(dev);
905 skb_queue_tail(&ppp->file.xq, skb);
906 ppp_xmit_process(ppp);
911 ++ppp->dev->stats.tx_dropped;
916 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
918 struct ppp *ppp = netdev_priv(dev);
920 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
921 struct ppp_stats stats;
922 struct ppp_comp_stats cstats;
927 ppp_get_stats(ppp, &stats);
928 if (copy_to_user(addr, &stats, sizeof(stats)))
934 memset(&cstats, 0, sizeof(cstats));
936 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
938 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
939 if (copy_to_user(addr, &cstats, sizeof(cstats)))
946 if (copy_to_user(addr, vers, strlen(vers) + 1))
958 static const struct net_device_ops ppp_netdev_ops = {
959 .ndo_start_xmit = ppp_start_xmit,
960 .ndo_do_ioctl = ppp_net_ioctl,
963 static void ppp_setup(struct net_device *dev)
965 dev->netdev_ops = &ppp_netdev_ops;
966 dev->hard_header_len = PPP_HDRLEN;
969 dev->tx_queue_len = 3;
970 dev->type = ARPHRD_PPP;
971 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
975 * Transmit-side routines.
979 * Called to do any work queued up on the transmit side
980 * that can now be done.
983 ppp_xmit_process(struct ppp *ppp)
990 while (!ppp->xmit_pending
991 && (skb = skb_dequeue(&ppp->file.xq)))
992 ppp_send_frame(ppp, skb);
993 /* If there's no work left to do, tell the core net
994 code that we can accept some more. */
995 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
996 netif_wake_queue(ppp->dev);
998 ppp_xmit_unlock(ppp);
1001 static inline struct sk_buff *
1002 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1004 struct sk_buff *new_skb;
1006 int new_skb_size = ppp->dev->mtu +
1007 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1008 int compressor_skb_size = ppp->dev->mtu +
1009 ppp->xcomp->comp_extra + PPP_HDRLEN;
1010 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1012 if (net_ratelimit())
1013 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1016 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1017 skb_reserve(new_skb,
1018 ppp->dev->hard_header_len - PPP_HDRLEN);
1020 /* compressor still expects A/C bytes in hdr */
1021 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1022 new_skb->data, skb->len + 2,
1023 compressor_skb_size);
1024 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1028 skb_pull(skb, 2); /* pull off A/C bytes */
1029 } else if (len == 0) {
1030 /* didn't compress, or CCP not up yet */
1036 * MPPE requires that we do not send unencrypted
1037 * frames. The compressor will return -1 if we
1038 * should drop the frame. We cannot simply test
1039 * the compress_proto because MPPE and MPPC share
1042 if (net_ratelimit())
1043 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1052 * Compress and send a frame.
1053 * The caller should have locked the xmit path,
1054 * and xmit_pending should be 0.
1057 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1059 int proto = PPP_PROTO(skb);
1060 struct sk_buff *new_skb;
1064 if (proto < 0x8000) {
1065 #ifdef CONFIG_PPP_FILTER
1066 /* check if we should pass this packet */
1067 /* the filter instructions are constructed assuming
1068 a four-byte PPP header on each packet */
1069 *skb_push(skb, 2) = 1;
1070 if (ppp->pass_filter
1071 && sk_run_filter(skb, ppp->pass_filter,
1072 ppp->pass_len) == 0) {
1074 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1078 /* if this packet passes the active filter, record the time */
1079 if (!(ppp->active_filter
1080 && sk_run_filter(skb, ppp->active_filter,
1081 ppp->active_len) == 0))
1082 ppp->last_xmit = jiffies;
1085 /* for data packets, record the time */
1086 ppp->last_xmit = jiffies;
1087 #endif /* CONFIG_PPP_FILTER */
1090 ++ppp->dev->stats.tx_packets;
1091 ppp->dev->stats.tx_bytes += skb->len - 2;
1095 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1097 /* try to do VJ TCP header compression */
1098 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1101 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1104 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1106 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1107 new_skb->data + 2, &cp,
1108 !(ppp->flags & SC_NO_TCP_CCID));
1109 if (cp == skb->data + 2) {
1110 /* didn't compress */
1113 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1114 proto = PPP_VJC_COMP;
1115 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1117 proto = PPP_VJC_UNCOMP;
1118 cp[0] = skb->data[2];
1122 cp = skb_put(skb, len + 2);
1129 /* peek at outbound CCP frames */
1130 ppp_ccp_peek(ppp, skb, 0);
1134 /* try to do packet compression */
1135 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1136 && proto != PPP_LCP && proto != PPP_CCP) {
1137 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1138 if (net_ratelimit())
1139 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1142 skb = pad_compress_skb(ppp, skb);
1148 * If we are waiting for traffic (demand dialling),
1149 * queue it up for pppd to receive.
1151 if (ppp->flags & SC_LOOP_TRAFFIC) {
1152 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1154 skb_queue_tail(&ppp->file.rq, skb);
1155 wake_up_interruptible(&ppp->file.rwait);
1159 ppp->xmit_pending = skb;
1166 ++ppp->dev->stats.tx_errors;
1170 * Try to send the frame in xmit_pending.
1171 * The caller should have the xmit path locked.
1174 ppp_push(struct ppp *ppp)
1176 struct list_head *list;
1177 struct channel *pch;
1178 struct sk_buff *skb = ppp->xmit_pending;
1183 list = &ppp->channels;
1184 if (list_empty(list)) {
1185 /* nowhere to send the packet, just drop it */
1186 ppp->xmit_pending = NULL;
1191 if ((ppp->flags & SC_MULTILINK) == 0) {
1192 /* not doing multilink: send it down the first channel */
1194 pch = list_entry(list, struct channel, clist);
1196 spin_lock_bh(&pch->downl);
1198 if (pch->chan->ops->start_xmit(pch->chan, skb))
1199 ppp->xmit_pending = NULL;
1201 /* channel got unregistered */
1203 ppp->xmit_pending = NULL;
1205 spin_unlock_bh(&pch->downl);
1209 #ifdef CONFIG_PPP_MULTILINK
1210 /* Multilink: fragment the packet over as many links
1211 as can take the packet at the moment. */
1212 if (!ppp_mp_explode(ppp, skb))
1214 #endif /* CONFIG_PPP_MULTILINK */
1216 ppp->xmit_pending = NULL;
1220 #ifdef CONFIG_PPP_MULTILINK
1222 * Divide a packet to be transmitted into fragments and
1223 * send them out the individual links.
1225 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1228 int i, bits, hdrlen, mtu;
1232 unsigned char *p, *q;
1233 struct list_head *list;
1234 struct channel *pch;
1235 struct sk_buff *frag;
1236 struct ppp_channel *chan;
1238 nfree = 0; /* # channels which have no packet already queued */
1239 navail = 0; /* total # of usable channels (not deregistered) */
1240 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1242 list_for_each_entry(pch, &ppp->channels, clist) {
1243 navail += pch->avail = (pch->chan != NULL);
1245 if (skb_queue_empty(&pch->file.xq) ||
1250 if (!pch->had_frag && i < ppp->nxchan)
1257 * Don't start sending this packet unless at least half of
1258 * the channels are free. This gives much better TCP
1259 * performance if we have a lot of channels.
1261 if (nfree == 0 || nfree < navail / 2)
1262 return 0; /* can't take now, leave it in xmit_pending */
1264 /* Do protocol field compression (XXX this should be optional) */
1273 * Decide on fragment size.
1274 * We create a fragment for each free channel regardless of
1275 * how small they are (i.e. even 0 length) in order to minimize
1276 * the time that it will take to detect when a channel drops
1281 fragsize = DIV_ROUND_UP(fragsize, nfree);
1282 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1283 except if nbigger==0, then they all get fragsize. */
1284 nbigger = len % nfree;
1286 /* skip to the channel after the one we last used
1287 and start at that one */
1288 list = &ppp->channels;
1289 for (i = 0; i < ppp->nxchan; ++i) {
1291 if (list == &ppp->channels) {
1297 /* create a fragment for each channel */
1299 while (nfree > 0 || len > 0) {
1301 if (list == &ppp->channels) {
1305 pch = list_entry(list, struct channel, clist);
1311 * Skip this channel if it has a fragment pending already and
1312 * we haven't given a fragment to all of the free channels.
1314 if (pch->avail == 1) {
1322 /* check the channel's mtu and whether it is still attached. */
1323 spin_lock_bh(&pch->downl);
1324 if (pch->chan == NULL) {
1325 /* can't use this channel, it's being deregistered */
1326 spin_unlock_bh(&pch->downl);
1334 * Create a fragment for this channel of
1335 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1336 * If mtu+2-hdrlen < 4, that is a ridiculously small
1337 * MTU, so we use mtu = 2 + hdrlen.
1342 mtu = pch->chan->mtu + 2 - hdrlen;
1347 if (flen == len && nfree == 0)
1349 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1352 q = skb_put(frag, flen + hdrlen);
1354 /* make the MP header */
1357 if (ppp->flags & SC_MP_XSHORTSEQ) {
1358 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1362 q[3] = ppp->nxseq >> 16;
1363 q[4] = ppp->nxseq >> 8;
1369 * Unfortunately there is a bug in older versions of
1370 * the Linux PPP multilink reconstruction code where it
1371 * drops 0-length fragments. Therefore we make sure the
1372 * fragment has at least one byte of data. Any bytes
1373 * we add in this situation will end up as padding on the
1374 * end of the reconstructed packet.
1377 *skb_put(frag, 1) = 0;
1379 memcpy(q + hdrlen, p, flen);
1381 /* try to send it down the channel */
1383 if (!skb_queue_empty(&pch->file.xq) ||
1384 !chan->ops->start_xmit(chan, frag))
1385 skb_queue_tail(&pch->file.xq, frag);
1391 spin_unlock_bh(&pch->downl);
1393 if (--nbigger == 0 && fragsize > 0)
1401 spin_unlock_bh(&pch->downl);
1403 printk(KERN_ERR "PPP: no memory (fragment)\n");
1404 ++ppp->dev->stats.tx_errors;
1406 return 1; /* abandon the frame */
1408 #endif /* CONFIG_PPP_MULTILINK */
1411 * Try to send data out on a channel.
1414 ppp_channel_push(struct channel *pch)
1416 struct sk_buff *skb;
1419 spin_lock_bh(&pch->downl);
1421 while (!skb_queue_empty(&pch->file.xq)) {
1422 skb = skb_dequeue(&pch->file.xq);
1423 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1424 /* put the packet back and try again later */
1425 skb_queue_head(&pch->file.xq, skb);
1430 /* channel got deregistered */
1431 skb_queue_purge(&pch->file.xq);
1433 spin_unlock_bh(&pch->downl);
1434 /* see if there is anything from the attached unit to be sent */
1435 if (skb_queue_empty(&pch->file.xq)) {
1436 read_lock_bh(&pch->upl);
1439 ppp_xmit_process(ppp);
1440 read_unlock_bh(&pch->upl);
1445 * Receive-side routines.
1448 /* misuse a few fields of the skb for MP reconstruction */
1449 #define sequence priority
1450 #define BEbits cb[0]
1453 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1456 /* ppp->dev == 0 means interface is closing down */
1458 ppp_receive_frame(ppp, skb, pch);
1461 ppp_recv_unlock(ppp);
1465 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1467 struct channel *pch = chan->ppp;
1470 if (!pch || skb->len == 0) {
1475 proto = PPP_PROTO(skb);
1476 read_lock_bh(&pch->upl);
1477 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1478 /* put it on the channel queue */
1479 skb_queue_tail(&pch->file.rq, skb);
1480 /* drop old frames if queue too long */
1481 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1482 && (skb = skb_dequeue(&pch->file.rq)))
1484 wake_up_interruptible(&pch->file.rwait);
1486 ppp_do_recv(pch->ppp, skb, pch);
1488 read_unlock_bh(&pch->upl);
1491 /* Put a 0-length skb in the receive queue as an error indication */
1493 ppp_input_error(struct ppp_channel *chan, int code)
1495 struct channel *pch = chan->ppp;
1496 struct sk_buff *skb;
1501 read_lock_bh(&pch->upl);
1503 skb = alloc_skb(0, GFP_ATOMIC);
1505 skb->len = 0; /* probably unnecessary */
1507 ppp_do_recv(pch->ppp, skb, pch);
1510 read_unlock_bh(&pch->upl);
1514 * We come in here to process a received frame.
1515 * The receive side of the ppp unit is locked.
1518 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1520 if (pskb_may_pull(skb, 2)) {
1521 #ifdef CONFIG_PPP_MULTILINK
1522 /* XXX do channel-level decompression here */
1523 if (PPP_PROTO(skb) == PPP_MP)
1524 ppp_receive_mp_frame(ppp, skb, pch);
1526 #endif /* CONFIG_PPP_MULTILINK */
1527 ppp_receive_nonmp_frame(ppp, skb);
1532 /* note: a 0-length skb is used as an error indication */
1533 ++ppp->dev->stats.rx_length_errors;
1536 ppp_receive_error(ppp);
1540 ppp_receive_error(struct ppp *ppp)
1542 ++ppp->dev->stats.rx_errors;
1548 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1551 int proto, len, npi;
1554 * Decompress the frame, if compressed.
1555 * Note that some decompressors need to see uncompressed frames
1556 * that come in as well as compressed frames.
1558 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1559 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1560 skb = ppp_decompress_frame(ppp, skb);
1562 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1565 proto = PPP_PROTO(skb);
1568 /* decompress VJ compressed packets */
1569 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1572 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1573 /* copy to a new sk_buff with more tailroom */
1574 ns = dev_alloc_skb(skb->len + 128);
1576 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1580 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1585 skb->ip_summed = CHECKSUM_NONE;
1587 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1589 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1594 skb_put(skb, len - skb->len);
1595 else if (len < skb->len)
1600 case PPP_VJC_UNCOMP:
1601 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1604 /* Until we fix the decompressor need to make sure
1605 * data portion is linear.
1607 if (!pskb_may_pull(skb, skb->len))
1610 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1611 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1618 ppp_ccp_peek(ppp, skb, 1);
1622 ++ppp->dev->stats.rx_packets;
1623 ppp->dev->stats.rx_bytes += skb->len - 2;
1625 npi = proto_to_npindex(proto);
1627 /* control or unknown frame - pass it to pppd */
1628 skb_queue_tail(&ppp->file.rq, skb);
1629 /* limit queue length by dropping old frames */
1630 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1631 && (skb = skb_dequeue(&ppp->file.rq)))
1633 /* wake up any process polling or blocking on read */
1634 wake_up_interruptible(&ppp->file.rwait);
1637 /* network protocol frame - give it to the kernel */
1639 #ifdef CONFIG_PPP_FILTER
1640 /* check if the packet passes the pass and active filters */
1641 /* the filter instructions are constructed assuming
1642 a four-byte PPP header on each packet */
1643 if (ppp->pass_filter || ppp->active_filter) {
1644 if (skb_cloned(skb) &&
1645 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1648 *skb_push(skb, 2) = 0;
1649 if (ppp->pass_filter
1650 && sk_run_filter(skb, ppp->pass_filter,
1651 ppp->pass_len) == 0) {
1653 printk(KERN_DEBUG "PPP: inbound frame "
1658 if (!(ppp->active_filter
1659 && sk_run_filter(skb, ppp->active_filter,
1660 ppp->active_len) == 0))
1661 ppp->last_recv = jiffies;
1664 #endif /* CONFIG_PPP_FILTER */
1665 ppp->last_recv = jiffies;
1667 if ((ppp->dev->flags & IFF_UP) == 0
1668 || ppp->npmode[npi] != NPMODE_PASS) {
1671 /* chop off protocol */
1672 skb_pull_rcsum(skb, 2);
1673 skb->dev = ppp->dev;
1674 skb->protocol = htons(npindex_to_ethertype[npi]);
1675 skb_reset_mac_header(skb);
1683 ppp_receive_error(ppp);
1686 static struct sk_buff *
1687 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1689 int proto = PPP_PROTO(skb);
1693 /* Until we fix all the decompressor's need to make sure
1694 * data portion is linear.
1696 if (!pskb_may_pull(skb, skb->len))
1699 if (proto == PPP_COMP) {
1702 switch(ppp->rcomp->compress_proto) {
1704 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1707 obuff_size = ppp->mru + PPP_HDRLEN;
1711 ns = dev_alloc_skb(obuff_size);
1713 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1716 /* the decompressor still expects the A/C bytes in the hdr */
1717 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1718 skb->len + 2, ns->data, obuff_size);
1720 /* Pass the compressed frame to pppd as an
1721 error indication. */
1722 if (len == DECOMP_FATALERROR)
1723 ppp->rstate |= SC_DC_FERROR;
1731 skb_pull(skb, 2); /* pull off the A/C bytes */
1734 /* Uncompressed frame - pass to decompressor so it
1735 can update its dictionary if necessary. */
1736 if (ppp->rcomp->incomp)
1737 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1744 ppp->rstate |= SC_DC_ERROR;
1745 ppp_receive_error(ppp);
1749 #ifdef CONFIG_PPP_MULTILINK
1751 * Receive a multilink frame.
1752 * We put it on the reconstruction queue and then pull off
1753 * as many completed frames as we can.
1756 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1760 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1762 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1763 goto err; /* no good, throw it away */
1765 /* Decode sequence number and begin/end bits */
1766 if (ppp->flags & SC_MP_SHORTSEQ) {
1767 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1770 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1773 skb->BEbits = skb->data[2];
1774 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1777 * Do protocol ID decompression on the first fragment of each packet.
1779 if ((skb->BEbits & B) && (skb->data[0] & 1))
1780 *skb_push(skb, 1) = 0;
1783 * Expand sequence number to 32 bits, making it as close
1784 * as possible to ppp->minseq.
1786 seq |= ppp->minseq & ~mask;
1787 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1789 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1790 seq -= mask + 1; /* should never happen */
1791 skb->sequence = seq;
1795 * If this packet comes before the next one we were expecting,
1798 if (seq_before(seq, ppp->nextseq)) {
1800 ++ppp->dev->stats.rx_dropped;
1801 ppp_receive_error(ppp);
1806 * Reevaluate minseq, the minimum over all channels of the
1807 * last sequence number received on each channel. Because of
1808 * the increasing sequence number rule, we know that any fragment
1809 * before `minseq' which hasn't arrived is never going to arrive.
1810 * The list of channels can't change because we have the receive
1811 * side of the ppp unit locked.
1813 list_for_each_entry(ch, &ppp->channels, clist) {
1814 if (seq_before(ch->lastseq, seq))
1817 if (seq_before(ppp->minseq, seq))
1820 /* Put the fragment on the reconstruction queue */
1821 ppp_mp_insert(ppp, skb);
1823 /* If the queue is getting long, don't wait any longer for packets
1824 before the start of the queue. */
1825 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1826 struct sk_buff *skb = skb_peek(&ppp->mrq);
1827 if (seq_before(ppp->minseq, skb->sequence))
1828 ppp->minseq = skb->sequence;
1831 /* Pull completed packets off the queue and receive them. */
1832 while ((skb = ppp_mp_reconstruct(ppp)))
1833 ppp_receive_nonmp_frame(ppp, skb);
1839 ppp_receive_error(ppp);
1843 * Insert a fragment on the MP reconstruction queue.
1844 * The queue is ordered by increasing sequence number.
1847 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1850 struct sk_buff_head *list = &ppp->mrq;
1851 u32 seq = skb->sequence;
1853 /* N.B. we don't need to lock the list lock because we have the
1854 ppp unit receive-side lock. */
1855 skb_queue_walk(list, p) {
1856 if (seq_before(seq, p->sequence))
1859 __skb_queue_before(list, p, skb);
1863 * Reconstruct a packet from the MP fragment queue.
1864 * We go through increasing sequence numbers until we find a
1865 * complete packet, or we get to the sequence number for a fragment
1866 * which hasn't arrived but might still do so.
1868 static struct sk_buff *
1869 ppp_mp_reconstruct(struct ppp *ppp)
1871 u32 seq = ppp->nextseq;
1872 u32 minseq = ppp->minseq;
1873 struct sk_buff_head *list = &ppp->mrq;
1874 struct sk_buff *p, *next;
1875 struct sk_buff *head, *tail;
1876 struct sk_buff *skb = NULL;
1877 int lost = 0, len = 0;
1879 if (ppp->mrru == 0) /* do nothing until mrru is set */
1883 for (p = head; p != (struct sk_buff *) list; p = next) {
1885 if (seq_before(p->sequence, seq)) {
1886 /* this can't happen, anyway ignore the skb */
1887 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1892 if (p->sequence != seq) {
1893 /* Fragment `seq' is missing. If it is after
1894 minseq, it might arrive later, so stop here. */
1895 if (seq_after(seq, minseq))
1897 /* Fragment `seq' is lost, keep going. */
1899 seq = seq_before(minseq, p->sequence)?
1900 minseq + 1: p->sequence;
1906 * At this point we know that all the fragments from
1907 * ppp->nextseq to seq are either present or lost.
1908 * Also, there are no complete packets in the queue
1909 * that have no missing fragments and end before this
1913 /* B bit set indicates this fragment starts a packet */
1914 if (p->BEbits & B) {
1922 /* Got a complete packet yet? */
1923 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1924 if (len > ppp->mrru + 2) {
1925 ++ppp->dev->stats.rx_length_errors;
1926 printk(KERN_DEBUG "PPP: reconstructed packet"
1927 " is too long (%d)\n", len);
1928 } else if (p == head) {
1929 /* fragment is complete packet - reuse skb */
1933 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1934 ++ppp->dev->stats.rx_missed_errors;
1935 printk(KERN_DEBUG "PPP: no memory for "
1936 "reconstructed packet");
1941 ppp->nextseq = seq + 1;
1945 * If this is the ending fragment of a packet,
1946 * and we haven't found a complete valid packet yet,
1947 * we can discard up to and including this fragment.
1955 /* If we have a complete packet, copy it all into one skb. */
1957 /* If we have discarded any fragments,
1958 signal a receive error. */
1959 if (head->sequence != ppp->nextseq) {
1961 printk(KERN_DEBUG " missed pkts %u..%u\n",
1962 ppp->nextseq, head->sequence-1);
1963 ++ppp->dev->stats.rx_dropped;
1964 ppp_receive_error(ppp);
1968 /* copy to a single skb */
1969 for (p = head; p != tail->next; p = p->next)
1970 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1971 ppp->nextseq = tail->sequence + 1;
1975 /* Discard all the skbuffs that we have copied the data out of
1976 or that we can't use. */
1977 while ((p = list->next) != head) {
1978 __skb_unlink(p, list);
1984 #endif /* CONFIG_PPP_MULTILINK */
1987 * Channel interface.
1991 * Create a new, unattached ppp channel.
1994 ppp_register_channel(struct ppp_channel *chan)
1996 struct channel *pch;
1998 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2004 init_ppp_file(&pch->file, CHANNEL);
2005 pch->file.hdrlen = chan->hdrlen;
2006 #ifdef CONFIG_PPP_MULTILINK
2008 #endif /* CONFIG_PPP_MULTILINK */
2009 init_rwsem(&pch->chan_sem);
2010 spin_lock_init(&pch->downl);
2011 rwlock_init(&pch->upl);
2012 spin_lock_bh(&all_channels_lock);
2013 pch->file.index = ++last_channel_index;
2014 list_add(&pch->list, &new_channels);
2015 atomic_inc(&channel_count);
2016 spin_unlock_bh(&all_channels_lock);
2021 * Return the index of a channel.
2023 int ppp_channel_index(struct ppp_channel *chan)
2025 struct channel *pch = chan->ppp;
2028 return pch->file.index;
2033 * Return the PPP unit number to which a channel is connected.
2035 int ppp_unit_number(struct ppp_channel *chan)
2037 struct channel *pch = chan->ppp;
2041 read_lock_bh(&pch->upl);
2043 unit = pch->ppp->file.index;
2044 read_unlock_bh(&pch->upl);
2050 * Disconnect a channel from the generic layer.
2051 * This must be called in process context.
2054 ppp_unregister_channel(struct ppp_channel *chan)
2056 struct channel *pch = chan->ppp;
2059 return; /* should never happen */
2063 * This ensures that we have returned from any calls into the
2064 * the channel's start_xmit or ioctl routine before we proceed.
2066 down_write(&pch->chan_sem);
2067 spin_lock_bh(&pch->downl);
2069 spin_unlock_bh(&pch->downl);
2070 up_write(&pch->chan_sem);
2071 ppp_disconnect_channel(pch);
2072 spin_lock_bh(&all_channels_lock);
2073 list_del(&pch->list);
2074 spin_unlock_bh(&all_channels_lock);
2076 wake_up_interruptible(&pch->file.rwait);
2077 if (atomic_dec_and_test(&pch->file.refcnt))
2078 ppp_destroy_channel(pch);
2082 * Callback from a channel when it can accept more to transmit.
2083 * This should be called at BH/softirq level, not interrupt level.
2086 ppp_output_wakeup(struct ppp_channel *chan)
2088 struct channel *pch = chan->ppp;
2092 ppp_channel_push(pch);
2096 * Compression control.
2099 /* Process the PPPIOCSCOMPRESS ioctl. */
2101 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2104 struct compressor *cp, *ocomp;
2105 struct ppp_option_data data;
2106 void *state, *ostate;
2107 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2110 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2111 || (data.length <= CCP_MAX_OPTION_LENGTH
2112 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2115 if (data.length > CCP_MAX_OPTION_LENGTH
2116 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2119 cp = try_then_request_module(
2120 find_compressor(ccp_option[0]),
2121 "ppp-compress-%d", ccp_option[0]);
2126 if (data.transmit) {
2127 state = cp->comp_alloc(ccp_option, data.length);
2130 ppp->xstate &= ~SC_COMP_RUN;
2132 ostate = ppp->xc_state;
2134 ppp->xc_state = state;
2135 ppp_xmit_unlock(ppp);
2137 ocomp->comp_free(ostate);
2138 module_put(ocomp->owner);
2142 module_put(cp->owner);
2145 state = cp->decomp_alloc(ccp_option, data.length);
2148 ppp->rstate &= ~SC_DECOMP_RUN;
2150 ostate = ppp->rc_state;
2152 ppp->rc_state = state;
2153 ppp_recv_unlock(ppp);
2155 ocomp->decomp_free(ostate);
2156 module_put(ocomp->owner);
2160 module_put(cp->owner);
2168 * Look at a CCP packet and update our state accordingly.
2169 * We assume the caller has the xmit or recv path locked.
2172 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2177 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2178 return; /* no header */
2181 switch (CCP_CODE(dp)) {
2184 /* A ConfReq starts negotiation of compression
2185 * in one direction of transmission,
2186 * and hence brings it down...but which way?
2189 * A ConfReq indicates what the sender would like to receive
2192 /* He is proposing what I should send */
2193 ppp->xstate &= ~SC_COMP_RUN;
2195 /* I am proposing to what he should send */
2196 ppp->rstate &= ~SC_DECOMP_RUN;
2203 * CCP is going down, both directions of transmission
2205 ppp->rstate &= ~SC_DECOMP_RUN;
2206 ppp->xstate &= ~SC_COMP_RUN;
2210 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2212 len = CCP_LENGTH(dp);
2213 if (!pskb_may_pull(skb, len + 2))
2214 return; /* too short */
2217 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2220 /* we will start receiving compressed packets */
2223 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2224 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2225 ppp->rstate |= SC_DECOMP_RUN;
2226 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2229 /* we will soon start sending compressed packets */
2232 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2233 ppp->file.index, 0, ppp->debug))
2234 ppp->xstate |= SC_COMP_RUN;
2239 /* reset the [de]compressor */
2240 if ((ppp->flags & SC_CCP_UP) == 0)
2243 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2244 ppp->rcomp->decomp_reset(ppp->rc_state);
2245 ppp->rstate &= ~SC_DC_ERROR;
2248 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2249 ppp->xcomp->comp_reset(ppp->xc_state);
2255 /* Free up compression resources. */
2257 ppp_ccp_closed(struct ppp *ppp)
2259 void *xstate, *rstate;
2260 struct compressor *xcomp, *rcomp;
2263 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2266 xstate = ppp->xc_state;
2267 ppp->xc_state = NULL;
2270 rstate = ppp->rc_state;
2271 ppp->rc_state = NULL;
2275 xcomp->comp_free(xstate);
2276 module_put(xcomp->owner);
2279 rcomp->decomp_free(rstate);
2280 module_put(rcomp->owner);
2284 /* List of compressors. */
2285 static LIST_HEAD(compressor_list);
2286 static DEFINE_SPINLOCK(compressor_list_lock);
2288 struct compressor_entry {
2289 struct list_head list;
2290 struct compressor *comp;
2293 static struct compressor_entry *
2294 find_comp_entry(int proto)
2296 struct compressor_entry *ce;
2298 list_for_each_entry(ce, &compressor_list, list) {
2299 if (ce->comp->compress_proto == proto)
2305 /* Register a compressor */
2307 ppp_register_compressor(struct compressor *cp)
2309 struct compressor_entry *ce;
2311 spin_lock(&compressor_list_lock);
2313 if (find_comp_entry(cp->compress_proto))
2316 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2321 list_add(&ce->list, &compressor_list);
2323 spin_unlock(&compressor_list_lock);
2327 /* Unregister a compressor */
2329 ppp_unregister_compressor(struct compressor *cp)
2331 struct compressor_entry *ce;
2333 spin_lock(&compressor_list_lock);
2334 ce = find_comp_entry(cp->compress_proto);
2335 if (ce && ce->comp == cp) {
2336 list_del(&ce->list);
2339 spin_unlock(&compressor_list_lock);
2342 /* Find a compressor. */
2343 static struct compressor *
2344 find_compressor(int type)
2346 struct compressor_entry *ce;
2347 struct compressor *cp = NULL;
2349 spin_lock(&compressor_list_lock);
2350 ce = find_comp_entry(type);
2353 if (!try_module_get(cp->owner))
2356 spin_unlock(&compressor_list_lock);
2361 * Miscelleneous stuff.
2365 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2367 struct slcompress *vj = ppp->vj;
2369 memset(st, 0, sizeof(*st));
2370 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2371 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2372 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2373 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2374 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2375 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2378 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2379 st->vj.vjs_compressed = vj->sls_o_compressed;
2380 st->vj.vjs_searches = vj->sls_o_searches;
2381 st->vj.vjs_misses = vj->sls_o_misses;
2382 st->vj.vjs_errorin = vj->sls_i_error;
2383 st->vj.vjs_tossed = vj->sls_i_tossed;
2384 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2385 st->vj.vjs_compressedin = vj->sls_i_compressed;
2389 * Stuff for handling the lists of ppp units and channels
2390 * and for initialization.
2394 * Create a new ppp interface unit. Fails if it can't allocate memory
2395 * or if there is already a unit with the requested number.
2396 * unit == -1 means allocate a new number.
2399 ppp_create_interface(int unit, int *retp)
2402 struct net_device *dev = NULL;
2406 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup);
2410 ppp = netdev_priv(dev);
2413 init_ppp_file(&ppp->file, INTERFACE);
2414 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2415 for (i = 0; i < NUM_NP; ++i)
2416 ppp->npmode[i] = NPMODE_PASS;
2417 INIT_LIST_HEAD(&ppp->channels);
2418 spin_lock_init(&ppp->rlock);
2419 spin_lock_init(&ppp->wlock);
2420 #ifdef CONFIG_PPP_MULTILINK
2422 skb_queue_head_init(&ppp->mrq);
2423 #endif /* CONFIG_PPP_MULTILINK */
2426 mutex_lock(&all_ppp_mutex);
2429 unit = unit_get(&ppp_units_idr, ppp);
2435 if (unit_find(&ppp_units_idr, unit))
2436 goto out2; /* unit already exists */
2438 /* darn, someone is cheatting us? */
2444 /* Initialize the new ppp unit */
2445 ppp->file.index = unit;
2446 sprintf(dev->name, "ppp%d", unit);
2448 ret = register_netdev(dev);
2450 unit_put(&ppp_units_idr, unit);
2451 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2456 atomic_inc(&ppp_unit_count);
2457 mutex_unlock(&all_ppp_mutex);
2463 mutex_unlock(&all_ppp_mutex);
2471 * Initialize a ppp_file structure.
2474 init_ppp_file(struct ppp_file *pf, int kind)
2477 skb_queue_head_init(&pf->xq);
2478 skb_queue_head_init(&pf->rq);
2479 atomic_set(&pf->refcnt, 1);
2480 init_waitqueue_head(&pf->rwait);
2484 * Take down a ppp interface unit - called when the owning file
2485 * (the one that created the unit) is closed or detached.
2487 static void ppp_shutdown_interface(struct ppp *ppp)
2489 struct net_device *dev;
2491 mutex_lock(&all_ppp_mutex);
2496 /* This will call dev_close() for us. */
2498 unregister_netdev(dev);
2501 unit_put(&ppp_units_idr, ppp->file.index);
2504 wake_up_interruptible(&ppp->file.rwait);
2505 mutex_unlock(&all_ppp_mutex);
2509 * Free the memory used by a ppp unit. This is only called once
2510 * there are no channels connected to the unit and no file structs
2511 * that reference the unit.
2513 static void ppp_destroy_interface(struct ppp *ppp)
2515 atomic_dec(&ppp_unit_count);
2517 if (!ppp->file.dead || ppp->n_channels) {
2518 /* "can't happen" */
2519 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2520 "n_channels=%d !\n", ppp, ppp->file.dead,
2525 ppp_ccp_closed(ppp);
2530 skb_queue_purge(&ppp->file.xq);
2531 skb_queue_purge(&ppp->file.rq);
2532 #ifdef CONFIG_PPP_MULTILINK
2533 skb_queue_purge(&ppp->mrq);
2534 #endif /* CONFIG_PPP_MULTILINK */
2535 #ifdef CONFIG_PPP_FILTER
2536 kfree(ppp->pass_filter);
2537 ppp->pass_filter = NULL;
2538 kfree(ppp->active_filter);
2539 ppp->active_filter = NULL;
2540 #endif /* CONFIG_PPP_FILTER */
2542 if (ppp->xmit_pending)
2543 kfree_skb(ppp->xmit_pending);
2549 * Locate an existing ppp unit.
2550 * The caller should have locked the all_ppp_mutex.
2553 ppp_find_unit(int unit)
2555 return unit_find(&ppp_units_idr, unit);
2559 * Locate an existing ppp channel.
2560 * The caller should have locked the all_channels_lock.
2561 * First we look in the new_channels list, then in the
2562 * all_channels list. If found in the new_channels list,
2563 * we move it to the all_channels list. This is for speed
2564 * when we have a lot of channels in use.
2566 static struct channel *
2567 ppp_find_channel(int unit)
2569 struct channel *pch;
2571 list_for_each_entry(pch, &new_channels, list) {
2572 if (pch->file.index == unit) {
2573 list_move(&pch->list, &all_channels);
2577 list_for_each_entry(pch, &all_channels, list) {
2578 if (pch->file.index == unit)
2585 * Connect a PPP channel to a PPP interface unit.
2588 ppp_connect_channel(struct channel *pch, int unit)
2594 mutex_lock(&all_ppp_mutex);
2595 ppp = ppp_find_unit(unit);
2598 write_lock_bh(&pch->upl);
2604 if (pch->file.hdrlen > ppp->file.hdrlen)
2605 ppp->file.hdrlen = pch->file.hdrlen;
2606 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2607 if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
2608 ppp->dev->hard_header_len = hdrlen;
2609 list_add_tail(&pch->clist, &ppp->channels);
2612 atomic_inc(&ppp->file.refcnt);
2617 write_unlock_bh(&pch->upl);
2619 mutex_unlock(&all_ppp_mutex);
2624 * Disconnect a channel from its ppp unit.
2627 ppp_disconnect_channel(struct channel *pch)
2632 write_lock_bh(&pch->upl);
2635 write_unlock_bh(&pch->upl);
2637 /* remove it from the ppp unit's list */
2639 list_del(&pch->clist);
2640 if (--ppp->n_channels == 0)
2641 wake_up_interruptible(&ppp->file.rwait);
2643 if (atomic_dec_and_test(&ppp->file.refcnt))
2644 ppp_destroy_interface(ppp);
2651 * Free up the resources used by a ppp channel.
2653 static void ppp_destroy_channel(struct channel *pch)
2655 atomic_dec(&channel_count);
2657 if (!pch->file.dead) {
2658 /* "can't happen" */
2659 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2663 skb_queue_purge(&pch->file.xq);
2664 skb_queue_purge(&pch->file.rq);
2668 static void __exit ppp_cleanup(void)
2670 /* should never happen */
2671 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2672 printk(KERN_ERR "PPP: removing module but units remain!\n");
2673 unregister_chrdev(PPP_MAJOR, "ppp");
2674 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2675 class_destroy(ppp_class);
2676 idr_destroy(&ppp_units_idr);
2680 * Units handling. Caller must protect concurrent access
2681 * by holding all_ppp_mutex
2684 /* get new free unit number and associate pointer with it */
2685 static int unit_get(struct idr *p, void *ptr)
2690 if (idr_pre_get(p, GFP_KERNEL) == 0) {
2691 printk(KERN_ERR "Out of memory expanding drawable idr\n");
2695 err = idr_get_new_above(p, ptr, 0, &unit);
2702 /* put unit number back to a pool */
2703 static void unit_put(struct idr *p, int n)
2708 /* get pointer associated with the number */
2709 static void *unit_find(struct idr *p, int n)
2711 return idr_find(p, n);
2714 /* Module/initialization stuff */
2716 module_init(ppp_init);
2717 module_exit(ppp_cleanup);
2719 EXPORT_SYMBOL(ppp_register_channel);
2720 EXPORT_SYMBOL(ppp_unregister_channel);
2721 EXPORT_SYMBOL(ppp_channel_index);
2722 EXPORT_SYMBOL(ppp_unit_number);
2723 EXPORT_SYMBOL(ppp_input);
2724 EXPORT_SYMBOL(ppp_input_error);
2725 EXPORT_SYMBOL(ppp_output_wakeup);
2726 EXPORT_SYMBOL(ppp_register_compressor);
2727 EXPORT_SYMBOL(ppp_unregister_compressor);
2728 MODULE_LICENSE("GPL");
2729 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2730 MODULE_ALIAS("/dev/ppp");