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/netdevice.h>
31 #include <linux/poll.h>
32 #include <linux/ppp_defs.h>
33 #include <linux/filter.h>
34 #include <linux/if_ppp.h>
35 #include <linux/ppp_channel.h>
36 #include <linux/ppp-comp.h>
37 #include <linux/skbuff.h>
38 #include <linux/rtnetlink.h>
39 #include <linux/if_arp.h>
41 #include <linux/tcp.h>
42 #include <linux/smp_lock.h>
43 #include <linux/spinlock.h>
44 #include <linux/rwsem.h>
45 #include <linux/stddef.h>
46 #include <linux/device.h>
47 #include <linux/mutex.h>
48 #include <net/slhc_vj.h>
49 #include <asm/atomic.h>
51 #define PPP_VERSION "2.4.2"
54 * Network protocols we support.
56 #define NP_IP 0 /* Internet Protocol V4 */
57 #define NP_IPV6 1 /* Internet Protocol V6 */
58 #define NP_IPX 2 /* IPX protocol */
59 #define NP_AT 3 /* Appletalk protocol */
60 #define NP_MPLS_UC 4 /* MPLS unicast */
61 #define NP_MPLS_MC 5 /* MPLS multicast */
62 #define NUM_NP 6 /* Number of NPs. */
64 #define MPHDRLEN 6 /* multilink protocol header length */
65 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
66 #define MIN_FRAG_SIZE 64
69 * An instance of /dev/ppp can be associated with either a ppp
70 * interface unit or a ppp channel. In both cases, file->private_data
71 * points to one of these.
77 struct sk_buff_head xq; /* pppd transmit queue */
78 struct sk_buff_head rq; /* receive queue for pppd */
79 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
80 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
81 int hdrlen; /* space to leave for headers */
82 int index; /* interface unit / channel number */
83 int dead; /* unit/channel has been shut down */
86 #define PF_TO_X(pf, X) container_of(pf, X, file)
88 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
89 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
92 * Data structure describing one ppp unit.
93 * A ppp unit corresponds to a ppp network interface device
94 * and represents a multilink bundle.
95 * It can have 0 or more ppp channels connected to it.
98 struct ppp_file file; /* stuff for read/write/poll 0 */
99 struct file *owner; /* file that owns this unit 48 */
100 struct list_head channels; /* list of attached channels 4c */
101 int n_channels; /* how many channels are attached 54 */
102 spinlock_t rlock; /* lock for receive side 58 */
103 spinlock_t wlock; /* lock for transmit side 5c */
104 int mru; /* max receive unit 60 */
105 unsigned int flags; /* control bits 64 */
106 unsigned int xstate; /* transmit state bits 68 */
107 unsigned int rstate; /* receive state bits 6c */
108 int debug; /* debug flags 70 */
109 struct slcompress *vj; /* state for VJ header compression */
110 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
111 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
112 struct compressor *xcomp; /* transmit packet compressor 8c */
113 void *xc_state; /* its internal state 90 */
114 struct compressor *rcomp; /* receive decompressor 94 */
115 void *rc_state; /* its internal state 98 */
116 unsigned long last_xmit; /* jiffies when last pkt sent 9c */
117 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
118 struct net_device *dev; /* network interface device a4 */
119 int closing; /* is device closing down? a8 */
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 * A cardmap represents a mapping from unsigned integers to pointers,
177 * and provides a fast "find lowest unused number" operation.
178 * It uses a broad (32-way) tree with a bitmap at each level.
179 * It is designed to be space-efficient for small numbers of entries
180 * and time-efficient for large numbers of entries.
182 #define CARDMAP_ORDER 5
183 #define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
184 #define CARDMAP_MASK (CARDMAP_WIDTH - 1)
189 struct cardmap *parent;
190 void *ptr[CARDMAP_WIDTH];
192 static void *cardmap_get(struct cardmap *map, unsigned int nr);
193 static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
194 static unsigned int cardmap_find_first_free(struct cardmap *map);
195 static void cardmap_destroy(struct cardmap **map);
198 * all_ppp_mutex protects the all_ppp_units mapping.
199 * It also ensures that finding a ppp unit in the all_ppp_units map
200 * and updating its file.refcnt field is atomic.
202 static DEFINE_MUTEX(all_ppp_mutex);
203 static struct cardmap *all_ppp_units;
204 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
207 * all_channels_lock protects all_channels and last_channel_index,
208 * and the atomicity of find a channel and updating its file.refcnt
211 static DEFINE_SPINLOCK(all_channels_lock);
212 static LIST_HEAD(all_channels);
213 static LIST_HEAD(new_channels);
214 static int last_channel_index;
215 static atomic_t channel_count = ATOMIC_INIT(0);
217 /* Get the PPP protocol number from a skb */
218 #define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
220 /* We limit the length of ppp->file.rq to this (arbitrary) value */
221 #define PPP_MAX_RQLEN 32
224 * Maximum number of multilink fragments queued up.
225 * This has to be large enough to cope with the maximum latency of
226 * the slowest channel relative to the others. Strictly it should
227 * depend on the number of channels and their characteristics.
229 #define PPP_MP_MAX_QLEN 128
231 /* Multilink header bits. */
232 #define B 0x80 /* this fragment begins a packet */
233 #define E 0x40 /* this fragment ends a packet */
235 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */
236 #define seq_before(a, b) ((s32)((a) - (b)) < 0)
237 #define seq_after(a, b) ((s32)((a) - (b)) > 0)
240 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
241 unsigned int cmd, unsigned long arg);
242 static void ppp_xmit_process(struct ppp *ppp);
243 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
244 static void ppp_push(struct ppp *ppp);
245 static void ppp_channel_push(struct channel *pch);
246 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
247 struct channel *pch);
248 static void ppp_receive_error(struct ppp *ppp);
249 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
250 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
251 struct sk_buff *skb);
252 #ifdef CONFIG_PPP_MULTILINK
253 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
254 struct channel *pch);
255 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
256 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
257 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
258 #endif /* CONFIG_PPP_MULTILINK */
259 static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
260 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
261 static void ppp_ccp_closed(struct ppp *ppp);
262 static struct compressor *find_compressor(int type);
263 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
264 static struct ppp *ppp_create_interface(int unit, int *retp);
265 static void init_ppp_file(struct ppp_file *pf, int kind);
266 static void ppp_shutdown_interface(struct ppp *ppp);
267 static void ppp_destroy_interface(struct ppp *ppp);
268 static struct ppp *ppp_find_unit(int unit);
269 static struct channel *ppp_find_channel(int unit);
270 static int ppp_connect_channel(struct channel *pch, int unit);
271 static int ppp_disconnect_channel(struct channel *pch);
272 static void ppp_destroy_channel(struct channel *pch);
274 static struct class *ppp_class;
276 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
277 static inline int proto_to_npindex(int proto)
296 /* Translates an NP index into a PPP protocol number */
297 static const int npindex_to_proto[NUM_NP] = {
306 /* Translates an ethertype into an NP index */
307 static inline int ethertype_to_npindex(int ethertype)
327 /* Translates an NP index into an ethertype */
328 static const int npindex_to_ethertype[NUM_NP] = {
340 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
341 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
342 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
343 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
344 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
345 ppp_recv_lock(ppp); } while (0)
346 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
347 ppp_xmit_unlock(ppp); } while (0)
350 * /dev/ppp device routines.
351 * The /dev/ppp device is used by pppd to control the ppp unit.
352 * It supports the read, write, ioctl and poll functions.
353 * Open instances of /dev/ppp can be in one of three states:
354 * unattached, attached to a ppp unit, or attached to a ppp channel.
356 static int ppp_open(struct inode *inode, struct file *file)
360 * This could (should?) be enforced by the permissions on /dev/ppp.
362 if (!capable(CAP_NET_ADMIN))
367 static int ppp_release(struct inode *unused, struct file *file)
369 struct ppp_file *pf = file->private_data;
373 file->private_data = NULL;
374 if (pf->kind == INTERFACE) {
376 if (file == ppp->owner)
377 ppp_shutdown_interface(ppp);
379 if (atomic_dec_and_test(&pf->refcnt)) {
382 ppp_destroy_interface(PF_TO_PPP(pf));
385 ppp_destroy_channel(PF_TO_CHANNEL(pf));
393 static ssize_t ppp_read(struct file *file, char __user *buf,
394 size_t count, loff_t *ppos)
396 struct ppp_file *pf = file->private_data;
397 DECLARE_WAITQUEUE(wait, current);
399 struct sk_buff *skb = NULL;
405 add_wait_queue(&pf->rwait, &wait);
407 set_current_state(TASK_INTERRUPTIBLE);
408 skb = skb_dequeue(&pf->rq);
414 if (pf->kind == INTERFACE) {
416 * Return 0 (EOF) on an interface that has no
417 * channels connected, unless it is looping
418 * network traffic (demand mode).
420 struct ppp *ppp = PF_TO_PPP(pf);
421 if (ppp->n_channels == 0
422 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
426 if (file->f_flags & O_NONBLOCK)
429 if (signal_pending(current))
433 set_current_state(TASK_RUNNING);
434 remove_wait_queue(&pf->rwait, &wait);
440 if (skb->len > count)
443 if (copy_to_user(buf, skb->data, skb->len))
453 static ssize_t ppp_write(struct file *file, const char __user *buf,
454 size_t count, loff_t *ppos)
456 struct ppp_file *pf = file->private_data;
463 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
466 skb_reserve(skb, pf->hdrlen);
468 if (copy_from_user(skb_put(skb, count), buf, count)) {
473 skb_queue_tail(&pf->xq, skb);
477 ppp_xmit_process(PF_TO_PPP(pf));
480 ppp_channel_push(PF_TO_CHANNEL(pf));
490 /* No kernel lock - fine */
491 static unsigned int ppp_poll(struct file *file, poll_table *wait)
493 struct ppp_file *pf = file->private_data;
498 poll_wait(file, &pf->rwait, wait);
499 mask = POLLOUT | POLLWRNORM;
500 if (skb_peek(&pf->rq))
501 mask |= POLLIN | POLLRDNORM;
504 else if (pf->kind == INTERFACE) {
505 /* see comment in ppp_read */
506 struct ppp *ppp = PF_TO_PPP(pf);
507 if (ppp->n_channels == 0
508 && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
509 mask |= POLLIN | POLLRDNORM;
515 #ifdef CONFIG_PPP_FILTER
516 static int get_filter(void __user *arg, struct sock_filter **p)
518 struct sock_fprog uprog;
519 struct sock_filter *code = NULL;
522 if (copy_from_user(&uprog, arg, sizeof(uprog)))
530 len = uprog.len * sizeof(struct sock_filter);
531 code = kmalloc(len, GFP_KERNEL);
535 if (copy_from_user(code, uprog.filter, len)) {
540 err = sk_chk_filter(code, uprog.len);
549 #endif /* CONFIG_PPP_FILTER */
551 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
553 struct ppp_file *pf = file->private_data;
555 int err = -EFAULT, val, val2, i;
556 struct ppp_idle idle;
559 struct slcompress *vj;
560 void __user *argp = (void __user *)arg;
561 int __user *p = argp;
564 return ppp_unattached_ioctl(pf, file, cmd, arg);
566 if (cmd == PPPIOCDETACH) {
568 * We have to be careful here... if the file descriptor
569 * has been dup'd, we could have another process in the
570 * middle of a poll using the same file *, so we had
571 * better not free the interface data structures -
572 * instead we fail the ioctl. Even in this case, we
573 * shut down the interface if we are the owner of it.
574 * Actually, we should get rid of PPPIOCDETACH, userland
575 * (i.e. pppd) could achieve the same effect by closing
576 * this fd and reopening /dev/ppp.
580 if (pf->kind == INTERFACE) {
582 if (file == ppp->owner)
583 ppp_shutdown_interface(ppp);
585 if (atomic_long_read(&file->f_count) <= 2) {
586 ppp_release(NULL, file);
589 printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n",
590 atomic_long_read(&file->f_count));
595 if (pf->kind == CHANNEL) {
597 struct ppp_channel *chan;
600 pch = PF_TO_CHANNEL(pf);
604 if (get_user(unit, p))
606 err = ppp_connect_channel(pch, unit);
610 err = ppp_disconnect_channel(pch);
614 down_read(&pch->chan_sem);
617 if (chan && chan->ops->ioctl)
618 err = chan->ops->ioctl(chan, cmd, arg);
619 up_read(&pch->chan_sem);
625 if (pf->kind != INTERFACE) {
627 printk(KERN_ERR "PPP: not interface or channel??\n");
635 if (get_user(val, p))
642 if (get_user(val, p))
645 cflags = ppp->flags & ~val;
646 ppp->flags = val & SC_FLAG_BITS;
648 if (cflags & SC_CCP_OPEN)
654 val = ppp->flags | ppp->xstate | ppp->rstate;
655 if (put_user(val, p))
660 case PPPIOCSCOMPRESS:
661 err = ppp_set_compress(ppp, arg);
665 if (put_user(ppp->file.index, p))
671 if (get_user(val, p))
678 if (put_user(ppp->debug, p))
684 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
685 idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
686 if (copy_to_user(argp, &idle, sizeof(idle)))
692 if (get_user(val, p))
695 if ((val >> 16) != 0) {
699 vj = slhc_init(val2+1, val+1);
701 printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
715 if (copy_from_user(&npi, argp, sizeof(npi)))
717 err = proto_to_npindex(npi.protocol);
721 if (cmd == PPPIOCGNPMODE) {
723 npi.mode = ppp->npmode[i];
724 if (copy_to_user(argp, &npi, sizeof(npi)))
727 ppp->npmode[i] = npi.mode;
728 /* we may be able to transmit more packets now (??) */
729 netif_wake_queue(ppp->dev);
734 #ifdef CONFIG_PPP_FILTER
737 struct sock_filter *code;
738 err = get_filter(argp, &code);
741 kfree(ppp->pass_filter);
742 ppp->pass_filter = code;
751 struct sock_filter *code;
752 err = get_filter(argp, &code);
755 kfree(ppp->active_filter);
756 ppp->active_filter = code;
757 ppp->active_len = err;
763 #endif /* CONFIG_PPP_FILTER */
765 #ifdef CONFIG_PPP_MULTILINK
767 if (get_user(val, p))
771 ppp_recv_unlock(ppp);
774 #endif /* CONFIG_PPP_MULTILINK */
783 static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
784 unsigned int cmd, unsigned long arg)
786 int unit, err = -EFAULT;
788 struct channel *chan;
789 int __user *p = (int __user *)arg;
794 /* Create a new ppp unit */
795 if (get_user(unit, p))
797 ppp = ppp_create_interface(unit, &err);
800 file->private_data = &ppp->file;
803 if (put_user(ppp->file.index, p))
809 /* Attach to an existing ppp unit */
810 if (get_user(unit, p))
812 mutex_lock(&all_ppp_mutex);
814 ppp = ppp_find_unit(unit);
816 atomic_inc(&ppp->file.refcnt);
817 file->private_data = &ppp->file;
820 mutex_unlock(&all_ppp_mutex);
824 if (get_user(unit, p))
826 spin_lock_bh(&all_channels_lock);
828 chan = ppp_find_channel(unit);
830 atomic_inc(&chan->file.refcnt);
831 file->private_data = &chan->file;
834 spin_unlock_bh(&all_channels_lock);
844 static const struct file_operations ppp_device_fops = {
845 .owner = THIS_MODULE,
849 .unlocked_ioctl = ppp_ioctl,
851 .release = ppp_release
854 #define PPP_MAJOR 108
856 /* Called at boot time if ppp is compiled into the kernel,
857 or at module load time (from init_module) if compiled as a module. */
858 static int __init ppp_init(void)
862 printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
863 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
865 ppp_class = class_create(THIS_MODULE, "ppp");
866 if (IS_ERR(ppp_class)) {
867 err = PTR_ERR(ppp_class);
870 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL,
876 printk(KERN_ERR "failed to register PPP device (%d)\n", err);
880 unregister_chrdev(PPP_MAJOR, "ppp");
885 * Network interface unit routines.
888 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
890 struct ppp *ppp = (struct ppp *) dev->priv;
894 npi = ethertype_to_npindex(ntohs(skb->protocol));
898 /* Drop, accept or reject the packet */
899 switch (ppp->npmode[npi]) {
903 /* it would be nice to have a way to tell the network
904 system to queue this one up for later. */
911 /* Put the 2-byte PPP protocol number on the front,
912 making sure there is room for the address and control fields. */
913 if (skb_cow_head(skb, PPP_HDRLEN))
916 pp = skb_push(skb, 2);
917 proto = npindex_to_proto[npi];
921 netif_stop_queue(dev);
922 skb_queue_tail(&ppp->file.xq, skb);
923 ppp_xmit_process(ppp);
928 ++ppp->dev->stats.tx_dropped;
933 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
935 struct ppp *ppp = dev->priv;
937 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
938 struct ppp_stats stats;
939 struct ppp_comp_stats cstats;
944 ppp_get_stats(ppp, &stats);
945 if (copy_to_user(addr, &stats, sizeof(stats)))
951 memset(&cstats, 0, sizeof(cstats));
953 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
955 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
956 if (copy_to_user(addr, &cstats, sizeof(cstats)))
963 if (copy_to_user(addr, vers, strlen(vers) + 1))
975 static void ppp_setup(struct net_device *dev)
977 dev->hard_header_len = PPP_HDRLEN;
980 dev->tx_queue_len = 3;
981 dev->type = ARPHRD_PPP;
982 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
986 * Transmit-side routines.
990 * Called to do any work queued up on the transmit side
991 * that can now be done.
994 ppp_xmit_process(struct ppp *ppp)
1001 while (!ppp->xmit_pending
1002 && (skb = skb_dequeue(&ppp->file.xq)))
1003 ppp_send_frame(ppp, skb);
1004 /* If there's no work left to do, tell the core net
1005 code that we can accept some more. */
1006 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
1007 netif_wake_queue(ppp->dev);
1009 ppp_xmit_unlock(ppp);
1012 static inline struct sk_buff *
1013 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
1015 struct sk_buff *new_skb;
1017 int new_skb_size = ppp->dev->mtu +
1018 ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
1019 int compressor_skb_size = ppp->dev->mtu +
1020 ppp->xcomp->comp_extra + PPP_HDRLEN;
1021 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
1023 if (net_ratelimit())
1024 printk(KERN_ERR "PPP: no memory (comp pkt)\n");
1027 if (ppp->dev->hard_header_len > PPP_HDRLEN)
1028 skb_reserve(new_skb,
1029 ppp->dev->hard_header_len - PPP_HDRLEN);
1031 /* compressor still expects A/C bytes in hdr */
1032 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
1033 new_skb->data, skb->len + 2,
1034 compressor_skb_size);
1035 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
1039 skb_pull(skb, 2); /* pull off A/C bytes */
1040 } else if (len == 0) {
1041 /* didn't compress, or CCP not up yet */
1047 * MPPE requires that we do not send unencrypted
1048 * frames. The compressor will return -1 if we
1049 * should drop the frame. We cannot simply test
1050 * the compress_proto because MPPE and MPPC share
1053 if (net_ratelimit())
1054 printk(KERN_ERR "ppp: compressor dropped pkt\n");
1063 * Compress and send a frame.
1064 * The caller should have locked the xmit path,
1065 * and xmit_pending should be 0.
1068 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
1070 int proto = PPP_PROTO(skb);
1071 struct sk_buff *new_skb;
1075 if (proto < 0x8000) {
1076 #ifdef CONFIG_PPP_FILTER
1077 /* check if we should pass this packet */
1078 /* the filter instructions are constructed assuming
1079 a four-byte PPP header on each packet */
1080 *skb_push(skb, 2) = 1;
1081 if (ppp->pass_filter
1082 && sk_run_filter(skb, ppp->pass_filter,
1083 ppp->pass_len) == 0) {
1085 printk(KERN_DEBUG "PPP: outbound frame not passed\n");
1089 /* if this packet passes the active filter, record the time */
1090 if (!(ppp->active_filter
1091 && sk_run_filter(skb, ppp->active_filter,
1092 ppp->active_len) == 0))
1093 ppp->last_xmit = jiffies;
1096 /* for data packets, record the time */
1097 ppp->last_xmit = jiffies;
1098 #endif /* CONFIG_PPP_FILTER */
1101 ++ppp->dev->stats.tx_packets;
1102 ppp->dev->stats.tx_bytes += skb->len - 2;
1106 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
1108 /* try to do VJ TCP header compression */
1109 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
1112 printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
1115 skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
1117 len = slhc_compress(ppp->vj, cp, skb->len - 2,
1118 new_skb->data + 2, &cp,
1119 !(ppp->flags & SC_NO_TCP_CCID));
1120 if (cp == skb->data + 2) {
1121 /* didn't compress */
1124 if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
1125 proto = PPP_VJC_COMP;
1126 cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
1128 proto = PPP_VJC_UNCOMP;
1129 cp[0] = skb->data[2];
1133 cp = skb_put(skb, len + 2);
1140 /* peek at outbound CCP frames */
1141 ppp_ccp_peek(ppp, skb, 0);
1145 /* try to do packet compression */
1146 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
1147 && proto != PPP_LCP && proto != PPP_CCP) {
1148 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
1149 if (net_ratelimit())
1150 printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
1153 skb = pad_compress_skb(ppp, skb);
1159 * If we are waiting for traffic (demand dialling),
1160 * queue it up for pppd to receive.
1162 if (ppp->flags & SC_LOOP_TRAFFIC) {
1163 if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
1165 skb_queue_tail(&ppp->file.rq, skb);
1166 wake_up_interruptible(&ppp->file.rwait);
1170 ppp->xmit_pending = skb;
1177 ++ppp->dev->stats.tx_errors;
1181 * Try to send the frame in xmit_pending.
1182 * The caller should have the xmit path locked.
1185 ppp_push(struct ppp *ppp)
1187 struct list_head *list;
1188 struct channel *pch;
1189 struct sk_buff *skb = ppp->xmit_pending;
1194 list = &ppp->channels;
1195 if (list_empty(list)) {
1196 /* nowhere to send the packet, just drop it */
1197 ppp->xmit_pending = NULL;
1202 if ((ppp->flags & SC_MULTILINK) == 0) {
1203 /* not doing multilink: send it down the first channel */
1205 pch = list_entry(list, struct channel, clist);
1207 spin_lock_bh(&pch->downl);
1209 if (pch->chan->ops->start_xmit(pch->chan, skb))
1210 ppp->xmit_pending = NULL;
1212 /* channel got unregistered */
1214 ppp->xmit_pending = NULL;
1216 spin_unlock_bh(&pch->downl);
1220 #ifdef CONFIG_PPP_MULTILINK
1221 /* Multilink: fragment the packet over as many links
1222 as can take the packet at the moment. */
1223 if (!ppp_mp_explode(ppp, skb))
1225 #endif /* CONFIG_PPP_MULTILINK */
1227 ppp->xmit_pending = NULL;
1231 #ifdef CONFIG_PPP_MULTILINK
1233 * Divide a packet to be transmitted into fragments and
1234 * send them out the individual links.
1236 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
1239 int i, bits, hdrlen, mtu;
1243 unsigned char *p, *q;
1244 struct list_head *list;
1245 struct channel *pch;
1246 struct sk_buff *frag;
1247 struct ppp_channel *chan;
1249 nfree = 0; /* # channels which have no packet already queued */
1250 navail = 0; /* total # of usable channels (not deregistered) */
1251 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1253 list_for_each_entry(pch, &ppp->channels, clist) {
1254 navail += pch->avail = (pch->chan != NULL);
1256 if (skb_queue_empty(&pch->file.xq) ||
1261 if (!pch->had_frag && i < ppp->nxchan)
1268 * Don't start sending this packet unless at least half of
1269 * the channels are free. This gives much better TCP
1270 * performance if we have a lot of channels.
1272 if (nfree == 0 || nfree < navail / 2)
1273 return 0; /* can't take now, leave it in xmit_pending */
1275 /* Do protocol field compression (XXX this should be optional) */
1284 * Decide on fragment size.
1285 * We create a fragment for each free channel regardless of
1286 * how small they are (i.e. even 0 length) in order to minimize
1287 * the time that it will take to detect when a channel drops
1292 fragsize = DIV_ROUND_UP(fragsize, nfree);
1293 /* nbigger channels get fragsize bytes, the rest get fragsize-1,
1294 except if nbigger==0, then they all get fragsize. */
1295 nbigger = len % nfree;
1297 /* skip to the channel after the one we last used
1298 and start at that one */
1299 list = &ppp->channels;
1300 for (i = 0; i < ppp->nxchan; ++i) {
1302 if (list == &ppp->channels) {
1308 /* create a fragment for each channel */
1310 while (nfree > 0 || len > 0) {
1312 if (list == &ppp->channels) {
1316 pch = list_entry(list, struct channel, clist);
1322 * Skip this channel if it has a fragment pending already and
1323 * we haven't given a fragment to all of the free channels.
1325 if (pch->avail == 1) {
1333 /* check the channel's mtu and whether it is still attached. */
1334 spin_lock_bh(&pch->downl);
1335 if (pch->chan == NULL) {
1336 /* can't use this channel, it's being deregistered */
1337 spin_unlock_bh(&pch->downl);
1345 * Create a fragment for this channel of
1346 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
1347 * If mtu+2-hdrlen < 4, that is a ridiculously small
1348 * MTU, so we use mtu = 2 + hdrlen.
1353 mtu = pch->chan->mtu + 2 - hdrlen;
1358 if (flen == len && nfree == 0)
1360 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
1363 q = skb_put(frag, flen + hdrlen);
1365 /* make the MP header */
1368 if (ppp->flags & SC_MP_XSHORTSEQ) {
1369 q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
1373 q[3] = ppp->nxseq >> 16;
1374 q[4] = ppp->nxseq >> 8;
1380 * Unfortunately there is a bug in older versions of
1381 * the Linux PPP multilink reconstruction code where it
1382 * drops 0-length fragments. Therefore we make sure the
1383 * fragment has at least one byte of data. Any bytes
1384 * we add in this situation will end up as padding on the
1385 * end of the reconstructed packet.
1388 *skb_put(frag, 1) = 0;
1390 memcpy(q + hdrlen, p, flen);
1392 /* try to send it down the channel */
1394 if (!skb_queue_empty(&pch->file.xq) ||
1395 !chan->ops->start_xmit(chan, frag))
1396 skb_queue_tail(&pch->file.xq, frag);
1402 spin_unlock_bh(&pch->downl);
1404 if (--nbigger == 0 && fragsize > 0)
1412 spin_unlock_bh(&pch->downl);
1414 printk(KERN_ERR "PPP: no memory (fragment)\n");
1415 ++ppp->dev->stats.tx_errors;
1417 return 1; /* abandon the frame */
1419 #endif /* CONFIG_PPP_MULTILINK */
1422 * Try to send data out on a channel.
1425 ppp_channel_push(struct channel *pch)
1427 struct sk_buff *skb;
1430 spin_lock_bh(&pch->downl);
1432 while (!skb_queue_empty(&pch->file.xq)) {
1433 skb = skb_dequeue(&pch->file.xq);
1434 if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
1435 /* put the packet back and try again later */
1436 skb_queue_head(&pch->file.xq, skb);
1441 /* channel got deregistered */
1442 skb_queue_purge(&pch->file.xq);
1444 spin_unlock_bh(&pch->downl);
1445 /* see if there is anything from the attached unit to be sent */
1446 if (skb_queue_empty(&pch->file.xq)) {
1447 read_lock_bh(&pch->upl);
1450 ppp_xmit_process(ppp);
1451 read_unlock_bh(&pch->upl);
1456 * Receive-side routines.
1459 /* misuse a few fields of the skb for MP reconstruction */
1460 #define sequence priority
1461 #define BEbits cb[0]
1464 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1468 ppp_receive_frame(ppp, skb, pch);
1471 ppp_recv_unlock(ppp);
1475 ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
1477 struct channel *pch = chan->ppp;
1480 if (!pch || skb->len == 0) {
1485 proto = PPP_PROTO(skb);
1486 read_lock_bh(&pch->upl);
1487 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
1488 /* put it on the channel queue */
1489 skb_queue_tail(&pch->file.rq, skb);
1490 /* drop old frames if queue too long */
1491 while (pch->file.rq.qlen > PPP_MAX_RQLEN
1492 && (skb = skb_dequeue(&pch->file.rq)))
1494 wake_up_interruptible(&pch->file.rwait);
1496 ppp_do_recv(pch->ppp, skb, pch);
1498 read_unlock_bh(&pch->upl);
1501 /* Put a 0-length skb in the receive queue as an error indication */
1503 ppp_input_error(struct ppp_channel *chan, int code)
1505 struct channel *pch = chan->ppp;
1506 struct sk_buff *skb;
1511 read_lock_bh(&pch->upl);
1513 skb = alloc_skb(0, GFP_ATOMIC);
1515 skb->len = 0; /* probably unnecessary */
1517 ppp_do_recv(pch->ppp, skb, pch);
1520 read_unlock_bh(&pch->upl);
1524 * We come in here to process a received frame.
1525 * The receive side of the ppp unit is locked.
1528 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1530 if (pskb_may_pull(skb, 2)) {
1531 #ifdef CONFIG_PPP_MULTILINK
1532 /* XXX do channel-level decompression here */
1533 if (PPP_PROTO(skb) == PPP_MP)
1534 ppp_receive_mp_frame(ppp, skb, pch);
1536 #endif /* CONFIG_PPP_MULTILINK */
1537 ppp_receive_nonmp_frame(ppp, skb);
1542 /* note: a 0-length skb is used as an error indication */
1543 ++ppp->dev->stats.rx_length_errors;
1546 ppp_receive_error(ppp);
1550 ppp_receive_error(struct ppp *ppp)
1552 ++ppp->dev->stats.rx_errors;
1558 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
1561 int proto, len, npi;
1564 * Decompress the frame, if compressed.
1565 * Note that some decompressors need to see uncompressed frames
1566 * that come in as well as compressed frames.
1568 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
1569 && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
1570 skb = ppp_decompress_frame(ppp, skb);
1572 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
1575 proto = PPP_PROTO(skb);
1578 /* decompress VJ compressed packets */
1579 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1582 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
1583 /* copy to a new sk_buff with more tailroom */
1584 ns = dev_alloc_skb(skb->len + 128);
1586 printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
1590 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
1595 skb->ip_summed = CHECKSUM_NONE;
1597 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
1599 printk(KERN_DEBUG "PPP: VJ decompression error\n");
1604 skb_put(skb, len - skb->len);
1605 else if (len < skb->len)
1610 case PPP_VJC_UNCOMP:
1611 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
1614 /* Until we fix the decompressor need to make sure
1615 * data portion is linear.
1617 if (!pskb_may_pull(skb, skb->len))
1620 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
1621 printk(KERN_ERR "PPP: VJ uncompressed error\n");
1628 ppp_ccp_peek(ppp, skb, 1);
1632 ++ppp->dev->stats.rx_packets;
1633 ppp->dev->stats.rx_bytes += skb->len - 2;
1635 npi = proto_to_npindex(proto);
1637 /* control or unknown frame - pass it to pppd */
1638 skb_queue_tail(&ppp->file.rq, skb);
1639 /* limit queue length by dropping old frames */
1640 while (ppp->file.rq.qlen > PPP_MAX_RQLEN
1641 && (skb = skb_dequeue(&ppp->file.rq)))
1643 /* wake up any process polling or blocking on read */
1644 wake_up_interruptible(&ppp->file.rwait);
1647 /* network protocol frame - give it to the kernel */
1649 #ifdef CONFIG_PPP_FILTER
1650 /* check if the packet passes the pass and active filters */
1651 /* the filter instructions are constructed assuming
1652 a four-byte PPP header on each packet */
1653 if (ppp->pass_filter || ppp->active_filter) {
1654 if (skb_cloned(skb) &&
1655 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1658 *skb_push(skb, 2) = 0;
1659 if (ppp->pass_filter
1660 && sk_run_filter(skb, ppp->pass_filter,
1661 ppp->pass_len) == 0) {
1663 printk(KERN_DEBUG "PPP: inbound frame "
1668 if (!(ppp->active_filter
1669 && sk_run_filter(skb, ppp->active_filter,
1670 ppp->active_len) == 0))
1671 ppp->last_recv = jiffies;
1674 #endif /* CONFIG_PPP_FILTER */
1675 ppp->last_recv = jiffies;
1677 if ((ppp->dev->flags & IFF_UP) == 0
1678 || ppp->npmode[npi] != NPMODE_PASS) {
1681 /* chop off protocol */
1682 skb_pull_rcsum(skb, 2);
1683 skb->dev = ppp->dev;
1684 skb->protocol = htons(npindex_to_ethertype[npi]);
1685 skb_reset_mac_header(skb);
1687 ppp->dev->last_rx = jiffies;
1694 ppp_receive_error(ppp);
1697 static struct sk_buff *
1698 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
1700 int proto = PPP_PROTO(skb);
1704 /* Until we fix all the decompressor's need to make sure
1705 * data portion is linear.
1707 if (!pskb_may_pull(skb, skb->len))
1710 if (proto == PPP_COMP) {
1713 switch(ppp->rcomp->compress_proto) {
1715 obuff_size = ppp->mru + PPP_HDRLEN + 1;
1718 obuff_size = ppp->mru + PPP_HDRLEN;
1722 ns = dev_alloc_skb(obuff_size);
1724 printk(KERN_ERR "ppp_decompress_frame: no memory\n");
1727 /* the decompressor still expects the A/C bytes in the hdr */
1728 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
1729 skb->len + 2, ns->data, obuff_size);
1731 /* Pass the compressed frame to pppd as an
1732 error indication. */
1733 if (len == DECOMP_FATALERROR)
1734 ppp->rstate |= SC_DC_FERROR;
1742 skb_pull(skb, 2); /* pull off the A/C bytes */
1745 /* Uncompressed frame - pass to decompressor so it
1746 can update its dictionary if necessary. */
1747 if (ppp->rcomp->incomp)
1748 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
1755 ppp->rstate |= SC_DC_ERROR;
1756 ppp_receive_error(ppp);
1760 #ifdef CONFIG_PPP_MULTILINK
1762 * Receive a multilink frame.
1763 * We put it on the reconstruction queue and then pull off
1764 * as many completed frames as we can.
1767 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
1771 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
1773 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
1774 goto err; /* no good, throw it away */
1776 /* Decode sequence number and begin/end bits */
1777 if (ppp->flags & SC_MP_SHORTSEQ) {
1778 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
1781 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
1784 skb->BEbits = skb->data[2];
1785 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
1788 * Do protocol ID decompression on the first fragment of each packet.
1790 if ((skb->BEbits & B) && (skb->data[0] & 1))
1791 *skb_push(skb, 1) = 0;
1794 * Expand sequence number to 32 bits, making it as close
1795 * as possible to ppp->minseq.
1797 seq |= ppp->minseq & ~mask;
1798 if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
1800 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
1801 seq -= mask + 1; /* should never happen */
1802 skb->sequence = seq;
1806 * If this packet comes before the next one we were expecting,
1809 if (seq_before(seq, ppp->nextseq)) {
1811 ++ppp->dev->stats.rx_dropped;
1812 ppp_receive_error(ppp);
1817 * Reevaluate minseq, the minimum over all channels of the
1818 * last sequence number received on each channel. Because of
1819 * the increasing sequence number rule, we know that any fragment
1820 * before `minseq' which hasn't arrived is never going to arrive.
1821 * The list of channels can't change because we have the receive
1822 * side of the ppp unit locked.
1824 list_for_each_entry(ch, &ppp->channels, clist) {
1825 if (seq_before(ch->lastseq, seq))
1828 if (seq_before(ppp->minseq, seq))
1831 /* Put the fragment on the reconstruction queue */
1832 ppp_mp_insert(ppp, skb);
1834 /* If the queue is getting long, don't wait any longer for packets
1835 before the start of the queue. */
1836 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
1837 struct sk_buff *skb = skb_peek(&ppp->mrq);
1838 if (seq_before(ppp->minseq, skb->sequence))
1839 ppp->minseq = skb->sequence;
1842 /* Pull completed packets off the queue and receive them. */
1843 while ((skb = ppp_mp_reconstruct(ppp)))
1844 ppp_receive_nonmp_frame(ppp, skb);
1850 ppp_receive_error(ppp);
1854 * Insert a fragment on the MP reconstruction queue.
1855 * The queue is ordered by increasing sequence number.
1858 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
1861 struct sk_buff_head *list = &ppp->mrq;
1862 u32 seq = skb->sequence;
1864 /* N.B. we don't need to lock the list lock because we have the
1865 ppp unit receive-side lock. */
1866 skb_queue_walk(list, p) {
1867 if (seq_before(seq, p->sequence))
1870 __skb_queue_before(list, p, skb);
1874 * Reconstruct a packet from the MP fragment queue.
1875 * We go through increasing sequence numbers until we find a
1876 * complete packet, or we get to the sequence number for a fragment
1877 * which hasn't arrived but might still do so.
1879 static struct sk_buff *
1880 ppp_mp_reconstruct(struct ppp *ppp)
1882 u32 seq = ppp->nextseq;
1883 u32 minseq = ppp->minseq;
1884 struct sk_buff_head *list = &ppp->mrq;
1885 struct sk_buff *p, *next;
1886 struct sk_buff *head, *tail;
1887 struct sk_buff *skb = NULL;
1888 int lost = 0, len = 0;
1890 if (ppp->mrru == 0) /* do nothing until mrru is set */
1894 for (p = head; p != (struct sk_buff *) list; p = next) {
1896 if (seq_before(p->sequence, seq)) {
1897 /* this can't happen, anyway ignore the skb */
1898 printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
1903 if (p->sequence != seq) {
1904 /* Fragment `seq' is missing. If it is after
1905 minseq, it might arrive later, so stop here. */
1906 if (seq_after(seq, minseq))
1908 /* Fragment `seq' is lost, keep going. */
1910 seq = seq_before(minseq, p->sequence)?
1911 minseq + 1: p->sequence;
1917 * At this point we know that all the fragments from
1918 * ppp->nextseq to seq are either present or lost.
1919 * Also, there are no complete packets in the queue
1920 * that have no missing fragments and end before this
1924 /* B bit set indicates this fragment starts a packet */
1925 if (p->BEbits & B) {
1933 /* Got a complete packet yet? */
1934 if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
1935 if (len > ppp->mrru + 2) {
1936 ++ppp->dev->stats.rx_length_errors;
1937 printk(KERN_DEBUG "PPP: reconstructed packet"
1938 " is too long (%d)\n", len);
1939 } else if (p == head) {
1940 /* fragment is complete packet - reuse skb */
1944 } else if ((skb = dev_alloc_skb(len)) == NULL) {
1945 ++ppp->dev->stats.rx_missed_errors;
1946 printk(KERN_DEBUG "PPP: no memory for "
1947 "reconstructed packet");
1952 ppp->nextseq = seq + 1;
1956 * If this is the ending fragment of a packet,
1957 * and we haven't found a complete valid packet yet,
1958 * we can discard up to and including this fragment.
1966 /* If we have a complete packet, copy it all into one skb. */
1968 /* If we have discarded any fragments,
1969 signal a receive error. */
1970 if (head->sequence != ppp->nextseq) {
1972 printk(KERN_DEBUG " missed pkts %u..%u\n",
1973 ppp->nextseq, head->sequence-1);
1974 ++ppp->dev->stats.rx_dropped;
1975 ppp_receive_error(ppp);
1979 /* copy to a single skb */
1980 for (p = head; p != tail->next; p = p->next)
1981 skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
1982 ppp->nextseq = tail->sequence + 1;
1986 /* Discard all the skbuffs that we have copied the data out of
1987 or that we can't use. */
1988 while ((p = list->next) != head) {
1989 __skb_unlink(p, list);
1995 #endif /* CONFIG_PPP_MULTILINK */
1998 * Channel interface.
2002 * Create a new, unattached ppp channel.
2005 ppp_register_channel(struct ppp_channel *chan)
2007 struct channel *pch;
2009 pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
2015 init_ppp_file(&pch->file, CHANNEL);
2016 pch->file.hdrlen = chan->hdrlen;
2017 #ifdef CONFIG_PPP_MULTILINK
2019 #endif /* CONFIG_PPP_MULTILINK */
2020 init_rwsem(&pch->chan_sem);
2021 spin_lock_init(&pch->downl);
2022 rwlock_init(&pch->upl);
2023 spin_lock_bh(&all_channels_lock);
2024 pch->file.index = ++last_channel_index;
2025 list_add(&pch->list, &new_channels);
2026 atomic_inc(&channel_count);
2027 spin_unlock_bh(&all_channels_lock);
2032 * Return the index of a channel.
2034 int ppp_channel_index(struct ppp_channel *chan)
2036 struct channel *pch = chan->ppp;
2039 return pch->file.index;
2044 * Return the PPP unit number to which a channel is connected.
2046 int ppp_unit_number(struct ppp_channel *chan)
2048 struct channel *pch = chan->ppp;
2052 read_lock_bh(&pch->upl);
2054 unit = pch->ppp->file.index;
2055 read_unlock_bh(&pch->upl);
2061 * Disconnect a channel from the generic layer.
2062 * This must be called in process context.
2065 ppp_unregister_channel(struct ppp_channel *chan)
2067 struct channel *pch = chan->ppp;
2070 return; /* should never happen */
2074 * This ensures that we have returned from any calls into the
2075 * the channel's start_xmit or ioctl routine before we proceed.
2077 down_write(&pch->chan_sem);
2078 spin_lock_bh(&pch->downl);
2080 spin_unlock_bh(&pch->downl);
2081 up_write(&pch->chan_sem);
2082 ppp_disconnect_channel(pch);
2083 spin_lock_bh(&all_channels_lock);
2084 list_del(&pch->list);
2085 spin_unlock_bh(&all_channels_lock);
2087 wake_up_interruptible(&pch->file.rwait);
2088 if (atomic_dec_and_test(&pch->file.refcnt))
2089 ppp_destroy_channel(pch);
2093 * Callback from a channel when it can accept more to transmit.
2094 * This should be called at BH/softirq level, not interrupt level.
2097 ppp_output_wakeup(struct ppp_channel *chan)
2099 struct channel *pch = chan->ppp;
2103 ppp_channel_push(pch);
2107 * Compression control.
2110 /* Process the PPPIOCSCOMPRESS ioctl. */
2112 ppp_set_compress(struct ppp *ppp, unsigned long arg)
2115 struct compressor *cp, *ocomp;
2116 struct ppp_option_data data;
2117 void *state, *ostate;
2118 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
2121 if (copy_from_user(&data, (void __user *) arg, sizeof(data))
2122 || (data.length <= CCP_MAX_OPTION_LENGTH
2123 && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
2126 if (data.length > CCP_MAX_OPTION_LENGTH
2127 || ccp_option[1] < 2 || ccp_option[1] > data.length)
2130 cp = try_then_request_module(
2131 find_compressor(ccp_option[0]),
2132 "ppp-compress-%d", ccp_option[0]);
2137 if (data.transmit) {
2138 state = cp->comp_alloc(ccp_option, data.length);
2141 ppp->xstate &= ~SC_COMP_RUN;
2143 ostate = ppp->xc_state;
2145 ppp->xc_state = state;
2146 ppp_xmit_unlock(ppp);
2148 ocomp->comp_free(ostate);
2149 module_put(ocomp->owner);
2153 module_put(cp->owner);
2156 state = cp->decomp_alloc(ccp_option, data.length);
2159 ppp->rstate &= ~SC_DECOMP_RUN;
2161 ostate = ppp->rc_state;
2163 ppp->rc_state = state;
2164 ppp_recv_unlock(ppp);
2166 ocomp->decomp_free(ostate);
2167 module_put(ocomp->owner);
2171 module_put(cp->owner);
2179 * Look at a CCP packet and update our state accordingly.
2180 * We assume the caller has the xmit or recv path locked.
2183 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
2188 if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
2189 return; /* no header */
2192 switch (CCP_CODE(dp)) {
2195 /* A ConfReq starts negotiation of compression
2196 * in one direction of transmission,
2197 * and hence brings it down...but which way?
2200 * A ConfReq indicates what the sender would like to receive
2203 /* He is proposing what I should send */
2204 ppp->xstate &= ~SC_COMP_RUN;
2206 /* I am proposing to what he should send */
2207 ppp->rstate &= ~SC_DECOMP_RUN;
2214 * CCP is going down, both directions of transmission
2216 ppp->rstate &= ~SC_DECOMP_RUN;
2217 ppp->xstate &= ~SC_COMP_RUN;
2221 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
2223 len = CCP_LENGTH(dp);
2224 if (!pskb_may_pull(skb, len + 2))
2225 return; /* too short */
2228 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
2231 /* we will start receiving compressed packets */
2234 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
2235 ppp->file.index, 0, ppp->mru, ppp->debug)) {
2236 ppp->rstate |= SC_DECOMP_RUN;
2237 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
2240 /* we will soon start sending compressed packets */
2243 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
2244 ppp->file.index, 0, ppp->debug))
2245 ppp->xstate |= SC_COMP_RUN;
2250 /* reset the [de]compressor */
2251 if ((ppp->flags & SC_CCP_UP) == 0)
2254 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
2255 ppp->rcomp->decomp_reset(ppp->rc_state);
2256 ppp->rstate &= ~SC_DC_ERROR;
2259 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
2260 ppp->xcomp->comp_reset(ppp->xc_state);
2266 /* Free up compression resources. */
2268 ppp_ccp_closed(struct ppp *ppp)
2270 void *xstate, *rstate;
2271 struct compressor *xcomp, *rcomp;
2274 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
2277 xstate = ppp->xc_state;
2278 ppp->xc_state = NULL;
2281 rstate = ppp->rc_state;
2282 ppp->rc_state = NULL;
2286 xcomp->comp_free(xstate);
2287 module_put(xcomp->owner);
2290 rcomp->decomp_free(rstate);
2291 module_put(rcomp->owner);
2295 /* List of compressors. */
2296 static LIST_HEAD(compressor_list);
2297 static DEFINE_SPINLOCK(compressor_list_lock);
2299 struct compressor_entry {
2300 struct list_head list;
2301 struct compressor *comp;
2304 static struct compressor_entry *
2305 find_comp_entry(int proto)
2307 struct compressor_entry *ce;
2309 list_for_each_entry(ce, &compressor_list, list) {
2310 if (ce->comp->compress_proto == proto)
2316 /* Register a compressor */
2318 ppp_register_compressor(struct compressor *cp)
2320 struct compressor_entry *ce;
2322 spin_lock(&compressor_list_lock);
2324 if (find_comp_entry(cp->compress_proto))
2327 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
2332 list_add(&ce->list, &compressor_list);
2334 spin_unlock(&compressor_list_lock);
2338 /* Unregister a compressor */
2340 ppp_unregister_compressor(struct compressor *cp)
2342 struct compressor_entry *ce;
2344 spin_lock(&compressor_list_lock);
2345 ce = find_comp_entry(cp->compress_proto);
2346 if (ce && ce->comp == cp) {
2347 list_del(&ce->list);
2350 spin_unlock(&compressor_list_lock);
2353 /* Find a compressor. */
2354 static struct compressor *
2355 find_compressor(int type)
2357 struct compressor_entry *ce;
2358 struct compressor *cp = NULL;
2360 spin_lock(&compressor_list_lock);
2361 ce = find_comp_entry(type);
2364 if (!try_module_get(cp->owner))
2367 spin_unlock(&compressor_list_lock);
2372 * Miscelleneous stuff.
2376 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
2378 struct slcompress *vj = ppp->vj;
2380 memset(st, 0, sizeof(*st));
2381 st->p.ppp_ipackets = ppp->dev->stats.rx_packets;
2382 st->p.ppp_ierrors = ppp->dev->stats.rx_errors;
2383 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes;
2384 st->p.ppp_opackets = ppp->dev->stats.tx_packets;
2385 st->p.ppp_oerrors = ppp->dev->stats.tx_errors;
2386 st->p.ppp_obytes = ppp->dev->stats.tx_bytes;
2389 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
2390 st->vj.vjs_compressed = vj->sls_o_compressed;
2391 st->vj.vjs_searches = vj->sls_o_searches;
2392 st->vj.vjs_misses = vj->sls_o_misses;
2393 st->vj.vjs_errorin = vj->sls_i_error;
2394 st->vj.vjs_tossed = vj->sls_i_tossed;
2395 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
2396 st->vj.vjs_compressedin = vj->sls_i_compressed;
2400 * Stuff for handling the lists of ppp units and channels
2401 * and for initialization.
2405 * Create a new ppp interface unit. Fails if it can't allocate memory
2406 * or if there is already a unit with the requested number.
2407 * unit == -1 means allocate a new number.
2410 ppp_create_interface(int unit, int *retp)
2413 struct net_device *dev = NULL;
2417 ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
2420 dev = alloc_netdev(0, "", ppp_setup);
2425 init_ppp_file(&ppp->file, INTERFACE);
2426 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
2427 for (i = 0; i < NUM_NP; ++i)
2428 ppp->npmode[i] = NPMODE_PASS;
2429 INIT_LIST_HEAD(&ppp->channels);
2430 spin_lock_init(&ppp->rlock);
2431 spin_lock_init(&ppp->wlock);
2432 #ifdef CONFIG_PPP_MULTILINK
2434 skb_queue_head_init(&ppp->mrq);
2435 #endif /* CONFIG_PPP_MULTILINK */
2439 dev->hard_start_xmit = ppp_start_xmit;
2440 dev->do_ioctl = ppp_net_ioctl;
2443 mutex_lock(&all_ppp_mutex);
2445 unit = cardmap_find_first_free(all_ppp_units);
2446 else if (cardmap_get(all_ppp_units, unit) != NULL)
2447 goto out2; /* unit already exists */
2449 /* Initialize the new ppp unit */
2450 ppp->file.index = unit;
2451 sprintf(dev->name, "ppp%d", unit);
2453 ret = register_netdev(dev);
2455 printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
2460 atomic_inc(&ppp_unit_count);
2461 ret = cardmap_set(&all_ppp_units, unit, ppp);
2465 mutex_unlock(&all_ppp_mutex);
2470 atomic_dec(&ppp_unit_count);
2471 unregister_netdev(dev);
2473 mutex_unlock(&all_ppp_mutex);
2483 * Initialize a ppp_file structure.
2486 init_ppp_file(struct ppp_file *pf, int kind)
2489 skb_queue_head_init(&pf->xq);
2490 skb_queue_head_init(&pf->rq);
2491 atomic_set(&pf->refcnt, 1);
2492 init_waitqueue_head(&pf->rwait);
2496 * Take down a ppp interface unit - called when the owning file
2497 * (the one that created the unit) is closed or detached.
2499 static void ppp_shutdown_interface(struct ppp *ppp)
2501 mutex_lock(&all_ppp_mutex);
2502 /* This will call dev_close() for us. */
2504 if (!ppp->closing) {
2507 unregister_netdev(ppp->dev);
2511 cardmap_set(&all_ppp_units, ppp->file.index, NULL);
2514 wake_up_interruptible(&ppp->file.rwait);
2515 mutex_unlock(&all_ppp_mutex);
2519 * Free the memory used by a ppp unit. This is only called once
2520 * there are no channels connected to the unit and no file structs
2521 * that reference the unit.
2523 static void ppp_destroy_interface(struct ppp *ppp)
2525 atomic_dec(&ppp_unit_count);
2527 if (!ppp->file.dead || ppp->n_channels) {
2528 /* "can't happen" */
2529 printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
2530 "n_channels=%d !\n", ppp, ppp->file.dead,
2535 ppp_ccp_closed(ppp);
2540 skb_queue_purge(&ppp->file.xq);
2541 skb_queue_purge(&ppp->file.rq);
2542 #ifdef CONFIG_PPP_MULTILINK
2543 skb_queue_purge(&ppp->mrq);
2544 #endif /* CONFIG_PPP_MULTILINK */
2545 #ifdef CONFIG_PPP_FILTER
2546 kfree(ppp->pass_filter);
2547 ppp->pass_filter = NULL;
2548 kfree(ppp->active_filter);
2549 ppp->active_filter = NULL;
2550 #endif /* CONFIG_PPP_FILTER */
2552 if (ppp->xmit_pending)
2553 kfree_skb(ppp->xmit_pending);
2555 free_netdev(ppp->dev);
2559 * Locate an existing ppp unit.
2560 * The caller should have locked the all_ppp_mutex.
2563 ppp_find_unit(int unit)
2565 return cardmap_get(all_ppp_units, unit);
2569 * Locate an existing ppp channel.
2570 * The caller should have locked the all_channels_lock.
2571 * First we look in the new_channels list, then in the
2572 * all_channels list. If found in the new_channels list,
2573 * we move it to the all_channels list. This is for speed
2574 * when we have a lot of channels in use.
2576 static struct channel *
2577 ppp_find_channel(int unit)
2579 struct channel *pch;
2581 list_for_each_entry(pch, &new_channels, list) {
2582 if (pch->file.index == unit) {
2583 list_move(&pch->list, &all_channels);
2587 list_for_each_entry(pch, &all_channels, list) {
2588 if (pch->file.index == unit)
2595 * Connect a PPP channel to a PPP interface unit.
2598 ppp_connect_channel(struct channel *pch, int unit)
2604 mutex_lock(&all_ppp_mutex);
2605 ppp = ppp_find_unit(unit);
2608 write_lock_bh(&pch->upl);
2614 if (pch->file.hdrlen > ppp->file.hdrlen)
2615 ppp->file.hdrlen = pch->file.hdrlen;
2616 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
2617 if (hdrlen > ppp->dev->hard_header_len)
2618 ppp->dev->hard_header_len = hdrlen;
2619 list_add_tail(&pch->clist, &ppp->channels);
2622 atomic_inc(&ppp->file.refcnt);
2627 write_unlock_bh(&pch->upl);
2629 mutex_unlock(&all_ppp_mutex);
2634 * Disconnect a channel from its ppp unit.
2637 ppp_disconnect_channel(struct channel *pch)
2642 write_lock_bh(&pch->upl);
2645 write_unlock_bh(&pch->upl);
2647 /* remove it from the ppp unit's list */
2649 list_del(&pch->clist);
2650 if (--ppp->n_channels == 0)
2651 wake_up_interruptible(&ppp->file.rwait);
2653 if (atomic_dec_and_test(&ppp->file.refcnt))
2654 ppp_destroy_interface(ppp);
2661 * Free up the resources used by a ppp channel.
2663 static void ppp_destroy_channel(struct channel *pch)
2665 atomic_dec(&channel_count);
2667 if (!pch->file.dead) {
2668 /* "can't happen" */
2669 printk(KERN_ERR "ppp: destroying undead channel %p !\n",
2673 skb_queue_purge(&pch->file.xq);
2674 skb_queue_purge(&pch->file.rq);
2678 static void __exit ppp_cleanup(void)
2680 /* should never happen */
2681 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
2682 printk(KERN_ERR "PPP: removing module but units remain!\n");
2683 cardmap_destroy(&all_ppp_units);
2684 unregister_chrdev(PPP_MAJOR, "ppp");
2685 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
2686 class_destroy(ppp_class);
2690 * Cardmap implementation.
2692 static void *cardmap_get(struct cardmap *map, unsigned int nr)
2697 for (p = map; p != NULL; ) {
2698 if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
2702 nr &= ~(CARDMAP_MASK << p->shift);
2708 static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
2714 if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
2716 /* need a new top level */
2717 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2722 np->shift = p->shift + CARDMAP_ORDER;
2727 } while ((nr >> p->shift) >= CARDMAP_WIDTH);
2730 while (p->shift > 0) {
2731 i = (nr >> p->shift) & CARDMAP_MASK;
2732 if (p->ptr[i] == NULL) {
2733 struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
2736 np->shift = p->shift - CARDMAP_ORDER;
2741 clear_bit(i, &p->inuse);
2744 i = nr & CARDMAP_MASK;
2747 set_bit(i, &p->inuse);
2749 clear_bit(i, &p->inuse);
2755 static unsigned int cardmap_find_first_free(struct cardmap *map)
2758 unsigned int nr = 0;
2761 if ((p = map) == NULL)
2764 i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
2765 if (i >= CARDMAP_WIDTH) {
2766 if (p->parent == NULL)
2767 return CARDMAP_WIDTH << p->shift;
2769 i = (nr >> p->shift) & CARDMAP_MASK;
2770 set_bit(i, &p->inuse);
2773 nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
2774 if (p->shift == 0 || p->ptr[i] == NULL)
2780 static void cardmap_destroy(struct cardmap **pmap)
2782 struct cardmap *p, *np;
2785 for (p = *pmap; p != NULL; p = np) {
2786 if (p->shift != 0) {
2787 for (i = 0; i < CARDMAP_WIDTH; ++i)
2788 if (p->ptr[i] != NULL)
2790 if (i < CARDMAP_WIDTH) {
2802 /* Module/initialization stuff */
2804 module_init(ppp_init);
2805 module_exit(ppp_cleanup);
2807 EXPORT_SYMBOL(ppp_register_channel);
2808 EXPORT_SYMBOL(ppp_unregister_channel);
2809 EXPORT_SYMBOL(ppp_channel_index);
2810 EXPORT_SYMBOL(ppp_unit_number);
2811 EXPORT_SYMBOL(ppp_input);
2812 EXPORT_SYMBOL(ppp_input_error);
2813 EXPORT_SYMBOL(ppp_output_wakeup);
2814 EXPORT_SYMBOL(ppp_register_compressor);
2815 EXPORT_SYMBOL(ppp_unregister_compressor);
2816 MODULE_LICENSE("GPL");
2817 MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
2818 MODULE_ALIAS("/dev/ppp");