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-rw-r--r--drivers/net/ppp_generic.c2746
1 files changed, 2746 insertions, 0 deletions
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
new file mode 100644
index 000000000000..c456dc81b873
--- /dev/null
+++ b/drivers/net/ppp_generic.c
@@ -0,0 +1,2746 @@
+/*
+ * Generic PPP layer for Linux.
+ *
+ * Copyright 1999-2002 Paul Mackerras.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * The generic PPP layer handles the PPP network interfaces, the
+ * /dev/ppp device, packet and VJ compression, and multilink.
+ * It talks to PPP `channels' via the interface defined in
+ * include/linux/ppp_channel.h. Channels provide the basic means for
+ * sending and receiving PPP frames on some kind of communications
+ * channel.
+ *
+ * Part of the code in this driver was inspired by the old async-only
+ * PPP driver, written by Michael Callahan and Al Longyear, and
+ * subsequently hacked by Paul Mackerras.
+ *
+ * ==FILEVERSION 20041108==
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/netdevice.h>
+#include <linux/poll.h>
+#include <linux/ppp_defs.h>
+#include <linux/filter.h>
+#include <linux/if_ppp.h>
+#include <linux/ppp_channel.h>
+#include <linux/ppp-comp.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_arp.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/spinlock.h>
+#include <linux/smp_lock.h>
+#include <linux/rwsem.h>
+#include <linux/stddef.h>
+#include <linux/device.h>
+#include <net/slhc_vj.h>
+#include <asm/atomic.h>
+
+#define PPP_VERSION "2.4.2"
+
+/*
+ * Network protocols we support.
+ */
+#define NP_IP 0 /* Internet Protocol V4 */
+#define NP_IPV6 1 /* Internet Protocol V6 */
+#define NP_IPX 2 /* IPX protocol */
+#define NP_AT 3 /* Appletalk protocol */
+#define NP_MPLS_UC 4 /* MPLS unicast */
+#define NP_MPLS_MC 5 /* MPLS multicast */
+#define NUM_NP 6 /* Number of NPs. */
+
+#define MPHDRLEN 6 /* multilink protocol header length */
+#define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */
+#define MIN_FRAG_SIZE 64
+
+/*
+ * An instance of /dev/ppp can be associated with either a ppp
+ * interface unit or a ppp channel. In both cases, file->private_data
+ * points to one of these.
+ */
+struct ppp_file {
+ enum {
+ INTERFACE=1, CHANNEL
+ } kind;
+ struct sk_buff_head xq; /* pppd transmit queue */
+ struct sk_buff_head rq; /* receive queue for pppd */
+ wait_queue_head_t rwait; /* for poll on reading /dev/ppp */
+ atomic_t refcnt; /* # refs (incl /dev/ppp attached) */
+ int hdrlen; /* space to leave for headers */
+ int index; /* interface unit / channel number */
+ int dead; /* unit/channel has been shut down */
+};
+
+#define PF_TO_X(pf, X) ((X *)((char *)(pf) - offsetof(X, file)))
+
+#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp)
+#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel)
+
+#define ROUNDUP(n, x) (((n) + (x) - 1) / (x))
+
+/*
+ * Data structure describing one ppp unit.
+ * A ppp unit corresponds to a ppp network interface device
+ * and represents a multilink bundle.
+ * It can have 0 or more ppp channels connected to it.
+ */
+struct ppp {
+ struct ppp_file file; /* stuff for read/write/poll 0 */
+ struct file *owner; /* file that owns this unit 48 */
+ struct list_head channels; /* list of attached channels 4c */
+ int n_channels; /* how many channels are attached 54 */
+ spinlock_t rlock; /* lock for receive side 58 */
+ spinlock_t wlock; /* lock for transmit side 5c */
+ int mru; /* max receive unit 60 */
+ unsigned int flags; /* control bits 64 */
+ unsigned int xstate; /* transmit state bits 68 */
+ unsigned int rstate; /* receive state bits 6c */
+ int debug; /* debug flags 70 */
+ struct slcompress *vj; /* state for VJ header compression */
+ enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */
+ struct sk_buff *xmit_pending; /* a packet ready to go out 88 */
+ struct compressor *xcomp; /* transmit packet compressor 8c */
+ void *xc_state; /* its internal state 90 */
+ struct compressor *rcomp; /* receive decompressor 94 */
+ void *rc_state; /* its internal state 98 */
+ unsigned long last_xmit; /* jiffies when last pkt sent 9c */
+ unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
+ struct net_device *dev; /* network interface device a4 */
+#ifdef CONFIG_PPP_MULTILINK
+ int nxchan; /* next channel to send something on */
+ u32 nxseq; /* next sequence number to send */
+ int mrru; /* MP: max reconst. receive unit */
+ u32 nextseq; /* MP: seq no of next packet */
+ u32 minseq; /* MP: min of most recent seqnos */
+ struct sk_buff_head mrq; /* MP: receive reconstruction queue */
+#endif /* CONFIG_PPP_MULTILINK */
+ struct net_device_stats stats; /* statistics */
+#ifdef CONFIG_PPP_FILTER
+ struct sock_filter *pass_filter; /* filter for packets to pass */
+ struct sock_filter *active_filter;/* filter for pkts to reset idle */
+ unsigned pass_len, active_len;
+#endif /* CONFIG_PPP_FILTER */
+};
+
+/*
+ * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
+ * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP.
+ * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
+ * Bits in xstate: SC_COMP_RUN
+ */
+#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
+ |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
+ |SC_COMP_TCP|SC_REJ_COMP_TCP)
+
+/*
+ * Private data structure for each channel.
+ * This includes the data structure used for multilink.
+ */
+struct channel {
+ struct ppp_file file; /* stuff for read/write/poll */
+ struct list_head list; /* link in all/new_channels list */
+ struct ppp_channel *chan; /* public channel data structure */
+ struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */
+ spinlock_t downl; /* protects `chan', file.xq dequeue */
+ struct ppp *ppp; /* ppp unit we're connected to */
+ struct list_head clist; /* link in list of channels per unit */
+ rwlock_t upl; /* protects `ppp' */
+#ifdef CONFIG_PPP_MULTILINK
+ u8 avail; /* flag used in multilink stuff */
+ u8 had_frag; /* >= 1 fragments have been sent */
+ u32 lastseq; /* MP: last sequence # received */
+#endif /* CONFIG_PPP_MULTILINK */
+};
+
+/*
+ * SMP locking issues:
+ * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
+ * list and the ppp.n_channels field, you need to take both locks
+ * before you modify them.
+ * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock ->
+ * channel.downl.
+ */
+
+/*
+ * A cardmap represents a mapping from unsigned integers to pointers,
+ * and provides a fast "find lowest unused number" operation.
+ * It uses a broad (32-way) tree with a bitmap at each level.
+ * It is designed to be space-efficient for small numbers of entries
+ * and time-efficient for large numbers of entries.
+ */
+#define CARDMAP_ORDER 5
+#define CARDMAP_WIDTH (1U << CARDMAP_ORDER)
+#define CARDMAP_MASK (CARDMAP_WIDTH - 1)
+
+struct cardmap {
+ int shift;
+ unsigned long inuse;
+ struct cardmap *parent;
+ void *ptr[CARDMAP_WIDTH];
+};
+static void *cardmap_get(struct cardmap *map, unsigned int nr);
+static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
+static unsigned int cardmap_find_first_free(struct cardmap *map);
+static void cardmap_destroy(struct cardmap **map);
+
+/*
+ * all_ppp_sem protects the all_ppp_units mapping.
+ * It also ensures that finding a ppp unit in the all_ppp_units map
+ * and updating its file.refcnt field is atomic.
+ */
+static DECLARE_MUTEX(all_ppp_sem);
+static struct cardmap *all_ppp_units;
+static atomic_t ppp_unit_count = ATOMIC_INIT(0);
+
+/*
+ * all_channels_lock protects all_channels and last_channel_index,
+ * and the atomicity of find a channel and updating its file.refcnt
+ * field.
+ */
+static DEFINE_SPINLOCK(all_channels_lock);
+static LIST_HEAD(all_channels);
+static LIST_HEAD(new_channels);
+static int last_channel_index;
+static atomic_t channel_count = ATOMIC_INIT(0);
+
+/* Get the PPP protocol number from a skb */
+#define PPP_PROTO(skb) (((skb)->data[0] << 8) + (skb)->data[1])
+
+/* We limit the length of ppp->file.rq to this (arbitrary) value */
+#define PPP_MAX_RQLEN 32
+
+/*
+ * Maximum number of multilink fragments queued up.
+ * This has to be large enough to cope with the maximum latency of
+ * the slowest channel relative to the others. Strictly it should
+ * depend on the number of channels and their characteristics.
+ */
+#define PPP_MP_MAX_QLEN 128
+
+/* Multilink header bits. */
+#define B 0x80 /* this fragment begins a packet */
+#define E 0x40 /* this fragment ends a packet */
+
+/* Compare multilink sequence numbers (assumed to be 32 bits wide) */
+#define seq_before(a, b) ((s32)((a) - (b)) < 0)
+#define seq_after(a, b) ((s32)((a) - (b)) > 0)
+
+/* Prototypes. */
+static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
+ unsigned int cmd, unsigned long arg);
+static void ppp_xmit_process(struct ppp *ppp);
+static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb);
+static void ppp_push(struct ppp *ppp);
+static void ppp_channel_push(struct channel *pch);
+static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb,
+ struct channel *pch);
+static void ppp_receive_error(struct ppp *ppp);
+static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb);
+static struct sk_buff *ppp_decompress_frame(struct ppp *ppp,
+ struct sk_buff *skb);
+#ifdef CONFIG_PPP_MULTILINK
+static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb,
+ struct channel *pch);
+static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb);
+static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp);
+static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb);
+#endif /* CONFIG_PPP_MULTILINK */
+static int ppp_set_compress(struct ppp *ppp, unsigned long arg);
+static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound);
+static void ppp_ccp_closed(struct ppp *ppp);
+static struct compressor *find_compressor(int type);
+static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);
+static struct ppp *ppp_create_interface(int unit, int *retp);
+static void init_ppp_file(struct ppp_file *pf, int kind);
+static void ppp_shutdown_interface(struct ppp *ppp);
+static void ppp_destroy_interface(struct ppp *ppp);
+static struct ppp *ppp_find_unit(int unit);
+static struct channel *ppp_find_channel(int unit);
+static int ppp_connect_channel(struct channel *pch, int unit);
+static int ppp_disconnect_channel(struct channel *pch);
+static void ppp_destroy_channel(struct channel *pch);
+
+static struct class_simple *ppp_class;
+
+/* Translates a PPP protocol number to a NP index (NP == network protocol) */
+static inline int proto_to_npindex(int proto)
+{
+ switch (proto) {
+ case PPP_IP:
+ return NP_IP;
+ case PPP_IPV6:
+ return NP_IPV6;
+ case PPP_IPX:
+ return NP_IPX;
+ case PPP_AT:
+ return NP_AT;
+ case PPP_MPLS_UC:
+ return NP_MPLS_UC;
+ case PPP_MPLS_MC:
+ return NP_MPLS_MC;
+ }
+ return -EINVAL;
+}
+
+/* Translates an NP index into a PPP protocol number */
+static const int npindex_to_proto[NUM_NP] = {
+ PPP_IP,
+ PPP_IPV6,
+ PPP_IPX,
+ PPP_AT,
+ PPP_MPLS_UC,
+ PPP_MPLS_MC,
+};
+
+/* Translates an ethertype into an NP index */
+static inline int ethertype_to_npindex(int ethertype)
+{
+ switch (ethertype) {
+ case ETH_P_IP:
+ return NP_IP;
+ case ETH_P_IPV6:
+ return NP_IPV6;
+ case ETH_P_IPX:
+ return NP_IPX;
+ case ETH_P_PPPTALK:
+ case ETH_P_ATALK:
+ return NP_AT;
+ case ETH_P_MPLS_UC:
+ return NP_MPLS_UC;
+ case ETH_P_MPLS_MC:
+ return NP_MPLS_MC;
+ }
+ return -1;
+}
+
+/* Translates an NP index into an ethertype */
+static const int npindex_to_ethertype[NUM_NP] = {
+ ETH_P_IP,
+ ETH_P_IPV6,
+ ETH_P_IPX,
+ ETH_P_PPPTALK,
+ ETH_P_MPLS_UC,
+ ETH_P_MPLS_MC,
+};
+
+/*
+ * Locking shorthand.
+ */
+#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock)
+#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock)
+#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock)
+#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock)
+#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \
+ ppp_recv_lock(ppp); } while (0)
+#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \
+ ppp_xmit_unlock(ppp); } while (0)
+
+/*
+ * /dev/ppp device routines.
+ * The /dev/ppp device is used by pppd to control the ppp unit.
+ * It supports the read, write, ioctl and poll functions.
+ * Open instances of /dev/ppp can be in one of three states:
+ * unattached, attached to a ppp unit, or attached to a ppp channel.
+ */
+static int ppp_open(struct inode *inode, struct file *file)
+{
+ /*
+ * This could (should?) be enforced by the permissions on /dev/ppp.
+ */
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+ return 0;
+}
+
+static int ppp_release(struct inode *inode, struct file *file)
+{
+ struct ppp_file *pf = file->private_data;
+ struct ppp *ppp;
+
+ if (pf != 0) {
+ file->private_data = NULL;
+ if (pf->kind == INTERFACE) {
+ ppp = PF_TO_PPP(pf);
+ if (file == ppp->owner)
+ ppp_shutdown_interface(ppp);
+ }
+ if (atomic_dec_and_test(&pf->refcnt)) {
+ switch (pf->kind) {
+ case INTERFACE:
+ ppp_destroy_interface(PF_TO_PPP(pf));
+ break;
+ case CHANNEL:
+ ppp_destroy_channel(PF_TO_CHANNEL(pf));
+ break;
+ }
+ }
+ }
+ return 0;
+}
+
+static ssize_t ppp_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct ppp_file *pf = file->private_data;
+ DECLARE_WAITQUEUE(wait, current);
+ ssize_t ret;
+ struct sk_buff *skb = NULL;
+
+ ret = count;
+
+ if (pf == 0)
+ return -ENXIO;
+ add_wait_queue(&pf->rwait, &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ skb = skb_dequeue(&pf->rq);
+ if (skb)
+ break;
+ ret = 0;
+ if (pf->dead)
+ break;
+ if (pf->kind == INTERFACE) {
+ /*
+ * Return 0 (EOF) on an interface that has no
+ * channels connected, unless it is looping
+ * network traffic (demand mode).
+ */
+ struct ppp *ppp = PF_TO_PPP(pf);
+ if (ppp->n_channels == 0
+ && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
+ break;
+ }
+ ret = -EAGAIN;
+ if (file->f_flags & O_NONBLOCK)
+ break;
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ break;
+ schedule();
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&pf->rwait, &wait);
+
+ if (skb == 0)
+ goto out;
+
+ ret = -EOVERFLOW;
+ if (skb->len > count)
+ goto outf;
+ ret = -EFAULT;
+ if (copy_to_user(buf, skb->data, skb->len))
+ goto outf;
+ ret = skb->len;
+
+ outf:
+ kfree_skb(skb);
+ out:
+ return ret;
+}
+
+static ssize_t ppp_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct ppp_file *pf = file->private_data;
+ struct sk_buff *skb;
+ ssize_t ret;
+
+ if (pf == 0)
+ return -ENXIO;
+ ret = -ENOMEM;
+ skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
+ if (skb == 0)
+ goto out;
+ skb_reserve(skb, pf->hdrlen);
+ ret = -EFAULT;
+ if (copy_from_user(skb_put(skb, count), buf, count)) {
+ kfree_skb(skb);
+ goto out;
+ }
+
+ skb_queue_tail(&pf->xq, skb);
+
+ switch (pf->kind) {
+ case INTERFACE:
+ ppp_xmit_process(PF_TO_PPP(pf));
+ break;
+ case CHANNEL:
+ ppp_channel_push(PF_TO_CHANNEL(pf));
+ break;
+ }
+
+ ret = count;
+
+ out:
+ return ret;
+}
+
+/* No kernel lock - fine */
+static unsigned int ppp_poll(struct file *file, poll_table *wait)
+{
+ struct ppp_file *pf = file->private_data;
+ unsigned int mask;
+
+ if (pf == 0)
+ return 0;
+ poll_wait(file, &pf->rwait, wait);
+ mask = POLLOUT | POLLWRNORM;
+ if (skb_peek(&pf->rq) != 0)
+ mask |= POLLIN | POLLRDNORM;
+ if (pf->dead)
+ mask |= POLLHUP;
+ else if (pf->kind == INTERFACE) {
+ /* see comment in ppp_read */
+ struct ppp *ppp = PF_TO_PPP(pf);
+ if (ppp->n_channels == 0
+ && (ppp->flags & SC_LOOP_TRAFFIC) == 0)
+ mask |= POLLIN | POLLRDNORM;
+ }
+
+ return mask;
+}
+
+#ifdef CONFIG_PPP_FILTER
+static int get_filter(void __user *arg, struct sock_filter **p)
+{
+ struct sock_fprog uprog;
+ struct sock_filter *code = NULL;
+ int len, err;
+
+ if (copy_from_user(&uprog, arg, sizeof(uprog)))
+ return -EFAULT;
+
+ if (uprog.len > BPF_MAXINSNS)
+ return -EINVAL;
+
+ if (!uprog.len) {
+ *p = NULL;
+ return 0;
+ }
+
+ len = uprog.len * sizeof(struct sock_filter);
+ code = kmalloc(len, GFP_KERNEL);
+ if (code == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(code, uprog.filter, len)) {
+ kfree(code);
+ return -EFAULT;
+ }
+
+ err = sk_chk_filter(code, uprog.len);
+ if (err) {
+ kfree(code);
+ return err;
+ }
+
+ *p = code;
+ return uprog.len;
+}
+#endif /* CONFIG_PPP_FILTER */
+
+static int ppp_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct ppp_file *pf = file->private_data;
+ struct ppp *ppp;
+ int err = -EFAULT, val, val2, i;
+ struct ppp_idle idle;
+ struct npioctl npi;
+ int unit, cflags;
+ struct slcompress *vj;
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+
+ if (pf == 0)
+ return ppp_unattached_ioctl(pf, file, cmd, arg);
+
+ if (cmd == PPPIOCDETACH) {
+ /*
+ * We have to be careful here... if the file descriptor
+ * has been dup'd, we could have another process in the
+ * middle of a poll using the same file *, so we had
+ * better not free the interface data structures -
+ * instead we fail the ioctl. Even in this case, we
+ * shut down the interface if we are the owner of it.
+ * Actually, we should get rid of PPPIOCDETACH, userland
+ * (i.e. pppd) could achieve the same effect by closing
+ * this fd and reopening /dev/ppp.
+ */
+ err = -EINVAL;
+ if (pf->kind == INTERFACE) {
+ ppp = PF_TO_PPP(pf);
+ if (file == ppp->owner)
+ ppp_shutdown_interface(ppp);
+ }
+ if (atomic_read(&file->f_count) <= 2) {
+ ppp_release(inode, file);
+ err = 0;
+ } else
+ printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%d\n",
+ atomic_read(&file->f_count));
+ return err;
+ }
+
+ if (pf->kind == CHANNEL) {
+ struct channel *pch = PF_TO_CHANNEL(pf);
+ struct ppp_channel *chan;
+
+ switch (cmd) {
+ case PPPIOCCONNECT:
+ if (get_user(unit, p))
+ break;
+ err = ppp_connect_channel(pch, unit);
+ break;
+
+ case PPPIOCDISCONN:
+ err = ppp_disconnect_channel(pch);
+ break;
+
+ default:
+ down_read(&pch->chan_sem);
+ chan = pch->chan;
+ err = -ENOTTY;
+ if (chan && chan->ops->ioctl)
+ err = chan->ops->ioctl(chan, cmd, arg);
+ up_read(&pch->chan_sem);
+ }
+ return err;
+ }
+
+ if (pf->kind != INTERFACE) {
+ /* can't happen */
+ printk(KERN_ERR "PPP: not interface or channel??\n");
+ return -EINVAL;
+ }
+
+ ppp = PF_TO_PPP(pf);
+ switch (cmd) {
+ case PPPIOCSMRU:
+ if (get_user(val, p))
+ break;
+ ppp->mru = val;
+ err = 0;
+ break;
+
+ case PPPIOCSFLAGS:
+ if (get_user(val, p))
+ break;
+ ppp_lock(ppp);
+ cflags = ppp->flags & ~val;
+ ppp->flags = val & SC_FLAG_BITS;
+ ppp_unlock(ppp);
+ if (cflags & SC_CCP_OPEN)
+ ppp_ccp_closed(ppp);
+ err = 0;
+ break;
+
+ case PPPIOCGFLAGS:
+ val = ppp->flags | ppp->xstate | ppp->rstate;
+ if (put_user(val, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCSCOMPRESS:
+ err = ppp_set_compress(ppp, arg);
+ break;
+
+ case PPPIOCGUNIT:
+ if (put_user(ppp->file.index, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCSDEBUG:
+ if (get_user(val, p))
+ break;
+ ppp->debug = val;
+ err = 0;
+ break;
+
+ case PPPIOCGDEBUG:
+ if (put_user(ppp->debug, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCGIDLE:
+ idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
+ idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
+ if (copy_to_user(argp, &idle, sizeof(idle)))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCSMAXCID:
+ if (get_user(val, p))
+ break;
+ val2 = 15;
+ if ((val >> 16) != 0) {
+ val2 = val >> 16;
+ val &= 0xffff;
+ }
+ vj = slhc_init(val2+1, val+1);
+ if (vj == 0) {
+ printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
+ err = -ENOMEM;
+ break;
+ }
+ ppp_lock(ppp);
+ if (ppp->vj != 0)
+ slhc_free(ppp->vj);
+ ppp->vj = vj;
+ ppp_unlock(ppp);
+ err = 0;
+ break;
+
+ case PPPIOCGNPMODE:
+ case PPPIOCSNPMODE:
+ if (copy_from_user(&npi, argp, sizeof(npi)))
+ break;
+ err = proto_to_npindex(npi.protocol);
+ if (err < 0)
+ break;
+ i = err;
+ if (cmd == PPPIOCGNPMODE) {
+ err = -EFAULT;
+ npi.mode = ppp->npmode[i];
+ if (copy_to_user(argp, &npi, sizeof(npi)))
+ break;
+ } else {
+ ppp->npmode[i] = npi.mode;
+ /* we may be able to transmit more packets now (??) */
+ netif_wake_queue(ppp->dev);
+ }
+ err = 0;
+ break;
+
+#ifdef CONFIG_PPP_FILTER
+ case PPPIOCSPASS:
+ {
+ struct sock_filter *code;
+ err = get_filter(argp, &code);
+ if (err >= 0) {
+ ppp_lock(ppp);
+ kfree(ppp->pass_filter);
+ ppp->pass_filter = code;
+ ppp->pass_len = err;
+ ppp_unlock(ppp);
+ err = 0;
+ }
+ break;
+ }
+ case PPPIOCSACTIVE:
+ {
+ struct sock_filter *code;
+ err = get_filter(argp, &code);
+ if (err >= 0) {
+ ppp_lock(ppp);
+ kfree(ppp->active_filter);
+ ppp->active_filter = code;
+ ppp->active_len = err;
+ ppp_unlock(ppp);
+ err = 0;
+ }
+ break;
+ }
+#endif /* CONFIG_PPP_FILTER */
+
+#ifdef CONFIG_PPP_MULTILINK
+ case PPPIOCSMRRU:
+ if (get_user(val, p))
+ break;
+ ppp_recv_lock(ppp);
+ ppp->mrru = val;
+ ppp_recv_unlock(ppp);
+ err = 0;
+ break;
+#endif /* CONFIG_PPP_MULTILINK */
+
+ default:
+ err = -ENOTTY;
+ }
+
+ return err;
+}
+
+static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int unit, err = -EFAULT;
+ struct ppp *ppp;
+ struct channel *chan;
+ int __user *p = (int __user *)arg;
+
+ switch (cmd) {
+ case PPPIOCNEWUNIT:
+ /* Create a new ppp unit */
+ if (get_user(unit, p))
+ break;
+ ppp = ppp_create_interface(unit, &err);
+ if (ppp == 0)
+ break;
+ file->private_data = &ppp->file;
+ ppp->owner = file;
+ err = -EFAULT;
+ if (put_user(ppp->file.index, p))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCATTACH:
+ /* Attach to an existing ppp unit */
+ if (get_user(unit, p))
+ break;
+ down(&all_ppp_sem);
+ err = -ENXIO;
+ ppp = ppp_find_unit(unit);
+ if (ppp != 0) {
+ atomic_inc(&ppp->file.refcnt);
+ file->private_data = &ppp->file;
+ err = 0;
+ }
+ up(&all_ppp_sem);
+ break;
+
+ case PPPIOCATTCHAN:
+ if (get_user(unit, p))
+ break;
+ spin_lock_bh(&all_channels_lock);
+ err = -ENXIO;
+ chan = ppp_find_channel(unit);
+ if (chan != 0) {
+ atomic_inc(&chan->file.refcnt);
+ file->private_data = &chan->file;
+ err = 0;
+ }
+ spin_unlock_bh(&all_channels_lock);
+ break;
+
+ default:
+ err = -ENOTTY;
+ }
+ return err;
+}
+
+static struct file_operations ppp_device_fops = {
+ .owner = THIS_MODULE,
+ .read = ppp_read,
+ .write = ppp_write,
+ .poll = ppp_poll,
+ .ioctl = ppp_ioctl,
+ .open = ppp_open,
+ .release = ppp_release
+};
+
+#define PPP_MAJOR 108
+
+/* Called at boot time if ppp is compiled into the kernel,
+ or at module load time (from init_module) if compiled as a module. */
+static int __init ppp_init(void)
+{
+ int err;
+
+ printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
+ err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
+ if (!err) {
+ ppp_class = class_simple_create(THIS_MODULE, "ppp");
+ if (IS_ERR(ppp_class)) {
+ err = PTR_ERR(ppp_class);
+ goto out_chrdev;
+ }
+ class_simple_device_add(ppp_class, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
+ err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0),
+ S_IFCHR|S_IRUSR|S_IWUSR, "ppp");
+ if (err)
+ goto out_class;
+ }
+
+out:
+ if (err)
+ printk(KERN_ERR "failed to register PPP device (%d)\n", err);
+ return err;
+
+out_class:
+ class_simple_device_remove(MKDEV(PPP_MAJOR,0));
+ class_simple_destroy(ppp_class);
+out_chrdev:
+ unregister_chrdev(PPP_MAJOR, "ppp");
+ goto out;
+}
+
+/*
+ * Network interface unit routines.
+ */
+static int
+ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ppp *ppp = (struct ppp *) dev->priv;
+ int npi, proto;
+ unsigned char *pp;
+
+ npi = ethertype_to_npindex(ntohs(skb->protocol));
+ if (npi < 0)
+ goto outf;
+
+ /* Drop, accept or reject the packet */
+ switch (ppp->npmode[npi]) {
+ case NPMODE_PASS:
+ break;
+ case NPMODE_QUEUE:
+ /* it would be nice to have a way to tell the network
+ system to queue this one up for later. */
+ goto outf;
+ case NPMODE_DROP:
+ case NPMODE_ERROR:
+ goto outf;
+ }
+
+ /* Put the 2-byte PPP protocol number on the front,
+ making sure there is room for the address and control fields. */
+ if (skb_headroom(skb) < PPP_HDRLEN) {
+ struct sk_buff *ns;
+
+ ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
+ if (ns == 0)
+ goto outf;
+ skb_reserve(ns, dev->hard_header_len);
+ skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
+ kfree_skb(skb);
+ skb = ns;
+ }
+ pp = skb_push(skb, 2);
+ proto = npindex_to_proto[npi];
+ pp[0] = proto >> 8;
+ pp[1] = proto;
+
+ netif_stop_queue(dev);
+ skb_queue_tail(&ppp->file.xq, skb);
+ ppp_xmit_process(ppp);
+ return 0;
+
+ outf:
+ kfree_skb(skb);
+ ++ppp->stats.tx_dropped;
+ return 0;
+}
+
+static struct net_device_stats *
+ppp_net_stats(struct net_device *dev)
+{
+ struct ppp *ppp = (struct ppp *) dev->priv;
+
+ return &ppp->stats;
+}
+
+static int
+ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ struct ppp *ppp = dev->priv;
+ int err = -EFAULT;
+ void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
+ struct ppp_stats stats;
+ struct ppp_comp_stats cstats;
+ char *vers;
+
+ switch (cmd) {
+ case SIOCGPPPSTATS:
+ ppp_get_stats(ppp, &stats);
+ if (copy_to_user(addr, &stats, sizeof(stats)))
+ break;
+ err = 0;
+ break;
+
+ case SIOCGPPPCSTATS:
+ memset(&cstats, 0, sizeof(cstats));
+ if (ppp->xc_state != 0)
+ ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
+ if (ppp->rc_state != 0)
+ ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
+ if (copy_to_user(addr, &cstats, sizeof(cstats)))
+ break;
+ err = 0;
+ break;
+
+ case SIOCGPPPVER:
+ vers = PPP_VERSION;
+ if (copy_to_user(addr, vers, strlen(vers) + 1))
+ break;
+ err = 0;
+ break;
+
+ default:
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+static void ppp_setup(struct net_device *dev)
+{
+ dev->hard_header_len = PPP_HDRLEN;
+ dev->mtu = PPP_MTU;
+ dev->addr_len = 0;
+ dev->tx_queue_len = 3;
+ dev->type = ARPHRD_PPP;
+ dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+}
+
+/*
+ * Transmit-side routines.
+ */
+
+/*
+ * Called to do any work queued up on the transmit side
+ * that can now be done.
+ */
+static void
+ppp_xmit_process(struct ppp *ppp)
+{
+ struct sk_buff *skb;
+
+ ppp_xmit_lock(ppp);
+ if (ppp->dev != 0) {
+ ppp_push(ppp);
+ while (ppp->xmit_pending == 0
+ && (skb = skb_dequeue(&ppp->file.xq)) != 0)
+ ppp_send_frame(ppp, skb);
+ /* If there's no work left to do, tell the core net
+ code that we can accept some more. */
+ if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
+ netif_wake_queue(ppp->dev);
+ }
+ ppp_xmit_unlock(ppp);
+}
+
+/*
+ * Compress and send a frame.
+ * The caller should have locked the xmit path,
+ * and xmit_pending should be 0.
+ */
+static void
+ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
+{
+ int proto = PPP_PROTO(skb);
+ struct sk_buff *new_skb;
+ int len;
+ unsigned char *cp;
+
+ if (proto < 0x8000) {
+#ifdef CONFIG_PPP_FILTER
+ /* check if we should pass this packet */
+ /* the filter instructions are constructed assuming
+ a four-byte PPP header on each packet */
+ *skb_push(skb, 2) = 1;
+ if (ppp->pass_filter
+ && sk_run_filter(skb, ppp->pass_filter,
+ ppp->pass_len) == 0) {
+ if (ppp->debug & 1)
+ printk(KERN_DEBUG "PPP: outbound frame not passed\n");
+ kfree_skb(skb);
+ return;
+ }
+ /* if this packet passes the active filter, record the time */
+ if (!(ppp->active_filter
+ && sk_run_filter(skb, ppp->active_filter,
+ ppp->active_len) == 0))
+ ppp->last_xmit = jiffies;
+ skb_pull(skb, 2);
+#else
+ /* for data packets, record the time */
+ ppp->last_xmit = jiffies;
+#endif /* CONFIG_PPP_FILTER */
+ }
+
+ ++ppp->stats.tx_packets;
+ ppp->stats.tx_bytes += skb->len - 2;
+
+ switch (proto) {
+ case PPP_IP:
+ if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
+ break;
+ /* try to do VJ TCP header compression */
+ new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
+ GFP_ATOMIC);
+ if (new_skb == 0) {
+ printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
+ goto drop;
+ }
+ skb_reserve(new_skb, ppp->dev->hard_header_len - 2);
+ cp = skb->data + 2;
+ len = slhc_compress(ppp->vj, cp, skb->len - 2,
+ new_skb->data + 2, &cp,
+ !(ppp->flags & SC_NO_TCP_CCID));
+ if (cp == skb->data + 2) {
+ /* didn't compress */
+ kfree_skb(new_skb);
+ } else {
+ if (cp[0] & SL_TYPE_COMPRESSED_TCP) {
+ proto = PPP_VJC_COMP;
+ cp[0] &= ~SL_TYPE_COMPRESSED_TCP;
+ } else {
+ proto = PPP_VJC_UNCOMP;
+ cp[0] = skb->data[2];
+ }
+ kfree_skb(skb);
+ skb = new_skb;
+ cp = skb_put(skb, len + 2);
+ cp[0] = 0;
+ cp[1] = proto;
+ }
+ break;
+
+ case PPP_CCP:
+ /* peek at outbound CCP frames */
+ ppp_ccp_peek(ppp, skb, 0);
+ break;
+ }
+
+ /* try to do packet compression */
+ if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
+ && proto != PPP_LCP && proto != PPP_CCP) {
+ new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len,
+ GFP_ATOMIC);
+ if (new_skb == 0) {
+ printk(KERN_ERR "PPP: no memory (comp pkt)\n");
+ goto drop;
+ }
+ if (ppp->dev->hard_header_len > PPP_HDRLEN)
+ skb_reserve(new_skb,
+ ppp->dev->hard_header_len - PPP_HDRLEN);
+
+ /* compressor still expects A/C bytes in hdr */
+ len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
+ new_skb->data, skb->len + 2,
+ ppp->dev->mtu + PPP_HDRLEN);
+ if (len > 0 && (ppp->flags & SC_CCP_UP)) {
+ kfree_skb(skb);
+ skb = new_skb;
+ skb_put(skb, len);
+ skb_pull(skb, 2); /* pull off A/C bytes */
+ } else {
+ /* didn't compress, or CCP not up yet */
+ kfree_skb(new_skb);
+ }
+ }
+
+ /*
+ * If we are waiting for traffic (demand dialling),
+ * queue it up for pppd to receive.
+ */
+ if (ppp->flags & SC_LOOP_TRAFFIC) {
+ if (ppp->file.rq.qlen > PPP_MAX_RQLEN)
+ goto drop;
+ skb_queue_tail(&ppp->file.rq, skb);
+ wake_up_interruptible(&ppp->file.rwait);
+ return;
+ }
+
+ ppp->xmit_pending = skb;
+ ppp_push(ppp);
+ return;
+
+ drop:
+ kfree_skb(skb);
+ ++ppp->stats.tx_errors;
+}
+
+/*
+ * Try to send the frame in xmit_pending.
+ * The caller should have the xmit path locked.
+ */
+static void
+ppp_push(struct ppp *ppp)
+{
+ struct list_head *list;
+ struct channel *pch;
+ struct sk_buff *skb = ppp->xmit_pending;
+
+ if (skb == 0)
+ return;
+
+ list = &ppp->channels;
+ if (list_empty(list)) {
+ /* nowhere to send the packet, just drop it */
+ ppp->xmit_pending = NULL;
+ kfree_skb(skb);
+ return;
+ }
+
+ if ((ppp->flags & SC_MULTILINK) == 0) {
+ /* not doing multilink: send it down the first channel */
+ list = list->next;
+ pch = list_entry(list, struct channel, clist);
+
+ spin_lock_bh(&pch->downl);
+ if (pch->chan) {
+ if (pch->chan->ops->start_xmit(pch->chan, skb))
+ ppp->xmit_pending = NULL;
+ } else {
+ /* channel got unregistered */
+ kfree_skb(skb);
+ ppp->xmit_pending = NULL;
+ }
+ spin_unlock_bh(&pch->downl);
+ return;
+ }
+
+#ifdef CONFIG_PPP_MULTILINK
+ /* Multilink: fragment the packet over as many links
+ as can take the packet at the moment. */
+ if (!ppp_mp_explode(ppp, skb))
+ return;
+#endif /* CONFIG_PPP_MULTILINK */
+
+ ppp->xmit_pending = NULL;
+ kfree_skb(skb);
+}
+
+#ifdef CONFIG_PPP_MULTILINK
+/*
+ * Divide a packet to be transmitted into fragments and
+ * send them out the individual links.
+ */
+static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
+{
+ int nch, len, fragsize;
+ int i, bits, hdrlen, mtu;
+ int flen, fnb;
+ unsigned char *p, *q;
+ struct list_head *list;
+ struct channel *pch;
+ struct sk_buff *frag;
+ struct ppp_channel *chan;
+
+ nch = 0;
+ hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
+ list = &ppp->channels;
+ while ((list = list->next) != &ppp->channels) {
+ pch = list_entry(list, struct channel, clist);
+ nch += pch->avail = (skb_queue_len(&pch->file.xq) == 0);
+ /*
+ * If a channel hasn't had a fragment yet, it has to get
+ * one before we send any fragments on later channels.
+ * If it can't take a fragment now, don't give any
+ * to subsequent channels.
+ */
+ if (!pch->had_frag && !pch->avail) {
+ while ((list = list->next) != &ppp->channels) {
+ pch = list_entry(list, struct channel, clist);
+ pch->avail = 0;
+ }
+ break;
+ }
+ }
+ if (nch == 0)
+ return 0; /* can't take now, leave it in xmit_pending */
+
+ /* Do protocol field compression (XXX this should be optional) */
+ p = skb->data;
+ len = skb->len;
+ if (*p == 0) {
+ ++p;
+ --len;
+ }
+
+ /* decide on fragment size */
+ fragsize = len;
+ if (nch > 1) {
+ int maxch = ROUNDUP(len, MIN_FRAG_SIZE);
+ if (nch > maxch)
+ nch = maxch;
+ fragsize = ROUNDUP(fragsize, nch);
+ }
+
+ /* skip to the channel after the one we last used
+ and start at that one */
+ for (i = 0; i < ppp->nxchan; ++i) {
+ list = list->next;
+ if (list == &ppp->channels) {
+ i = 0;
+ break;
+ }
+ }
+
+ /* create a fragment for each channel */
+ bits = B;
+ do {
+ list = list->next;
+ if (list == &ppp->channels) {
+ i = 0;
+ continue;
+ }
+ pch = list_entry(list, struct channel, clist);
+ ++i;
+ if (!pch->avail)
+ continue;
+
+ /* check the channel's mtu and whether it is still attached. */
+ spin_lock_bh(&pch->downl);
+ if (pch->chan == 0 || (mtu = pch->chan->mtu) < hdrlen) {
+ /* can't use this channel */
+ spin_unlock_bh(&pch->downl);
+ pch->avail = 0;
+ if (--nch == 0)
+ break;
+ continue;
+ }
+
+ /*
+ * We have to create multiple fragments for this channel
+ * if fragsize is greater than the channel's mtu.
+ */
+ if (fragsize > len)
+ fragsize = len;
+ for (flen = fragsize; flen > 0; flen -= fnb) {
+ fnb = flen;
+ if (fnb > mtu + 2 - hdrlen)
+ fnb = mtu + 2 - hdrlen;
+ if (fnb >= len)
+ bits |= E;
+ frag = alloc_skb(fnb + hdrlen, GFP_ATOMIC);
+ if (frag == 0)
+ goto noskb;
+ q = skb_put(frag, fnb + hdrlen);
+ /* make the MP header */
+ q[0] = PPP_MP >> 8;
+ q[1] = PPP_MP;
+ if (ppp->flags & SC_MP_XSHORTSEQ) {
+ q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
+ q[3] = ppp->nxseq;
+ } else {
+ q[2] = bits;
+ q[3] = ppp->nxseq >> 16;
+ q[4] = ppp->nxseq >> 8;
+ q[5] = ppp->nxseq;
+ }
+
+ /* copy the data in */
+ memcpy(q + hdrlen, p, fnb);
+
+ /* try to send it down the channel */
+ chan = pch->chan;
+ if (!chan->ops->start_xmit(chan, frag))
+ skb_queue_tail(&pch->file.xq, frag);
+ pch->had_frag = 1;
+ p += fnb;
+ len -= fnb;
+ ++ppp->nxseq;
+ bits = 0;
+ }
+ spin_unlock_bh(&pch->downl);
+ } while (len > 0);
+ ppp->nxchan = i;
+
+ return 1;
+
+ noskb:
+ spin_unlock_bh(&pch->downl);
+ if (ppp->debug & 1)
+ printk(KERN_ERR "PPP: no memory (fragment)\n");
+ ++ppp->stats.tx_errors;
+ ++ppp->nxseq;
+ return 1; /* abandon the frame */
+}
+#endif /* CONFIG_PPP_MULTILINK */
+
+/*
+ * Try to send data out on a channel.
+ */
+static void
+ppp_channel_push(struct channel *pch)
+{
+ struct sk_buff *skb;
+ struct ppp *ppp;
+
+ spin_lock_bh(&pch->downl);
+ if (pch->chan != 0) {
+ while (skb_queue_len(&pch->file.xq) > 0) {
+ skb = skb_dequeue(&pch->file.xq);
+ if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
+ /* put the packet back and try again later */
+ skb_queue_head(&pch->file.xq, skb);
+ break;
+ }
+ }
+ } else {
+ /* channel got deregistered */
+ skb_queue_purge(&pch->file.xq);
+ }
+ spin_unlock_bh(&pch->downl);
+ /* see if there is anything from the attached unit to be sent */
+ if (skb_queue_len(&pch->file.xq) == 0) {
+ read_lock_bh(&pch->upl);
+ ppp = pch->ppp;
+ if (ppp != 0)
+ ppp_xmit_process(ppp);
+ read_unlock_bh(&pch->upl);
+ }
+}
+
+/*
+ * Receive-side routines.
+ */
+
+/* misuse a few fields of the skb for MP reconstruction */
+#define sequence priority
+#define BEbits cb[0]
+
+static inline void
+ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
+{
+ ppp_recv_lock(ppp);
+ /* ppp->dev == 0 means interface is closing down */
+ if (ppp->dev != 0)
+ ppp_receive_frame(ppp, skb, pch);
+ else
+ kfree_skb(skb);
+ ppp_recv_unlock(ppp);
+}
+
+void
+ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
+{
+ struct channel *pch = chan->ppp;
+ int proto;
+
+ if (pch == 0 || skb->len == 0) {
+ kfree_skb(skb);
+ return;
+ }
+
+ proto = PPP_PROTO(skb);
+ read_lock_bh(&pch->upl);
+ if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
+ /* put it on the channel queue */
+ skb_queue_tail(&pch->file.rq, skb);
+ /* drop old frames if queue too long */
+ while (pch->file.rq.qlen > PPP_MAX_RQLEN
+ && (skb = skb_dequeue(&pch->file.rq)) != 0)
+ kfree_skb(skb);
+ wake_up_interruptible(&pch->file.rwait);
+ } else {
+ ppp_do_recv(pch->ppp, skb, pch);
+ }
+ read_unlock_bh(&pch->upl);
+}
+
+/* Put a 0-length skb in the receive queue as an error indication */
+void
+ppp_input_error(struct ppp_channel *chan, int code)
+{
+ struct channel *pch = chan->ppp;
+ struct sk_buff *skb;
+
+ if (pch == 0)
+ return;
+
+ read_lock_bh(&pch->upl);
+ if (pch->ppp != 0) {
+ skb = alloc_skb(0, GFP_ATOMIC);
+ if (skb != 0) {
+ skb->len = 0; /* probably unnecessary */
+ skb->cb[0] = code;
+ ppp_do_recv(pch->ppp, skb, pch);
+ }
+ }
+ read_unlock_bh(&pch->upl);
+}
+
+/*
+ * We come in here to process a received frame.
+ * The receive side of the ppp unit is locked.
+ */
+static void
+ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
+{
+ if (skb->len >= 2) {
+#ifdef CONFIG_PPP_MULTILINK
+ /* XXX do channel-level decompression here */
+ if (PPP_PROTO(skb) == PPP_MP)
+ ppp_receive_mp_frame(ppp, skb, pch);
+ else
+#endif /* CONFIG_PPP_MULTILINK */
+ ppp_receive_nonmp_frame(ppp, skb);
+ return;
+ }
+
+ if (skb->len > 0)
+ /* note: a 0-length skb is used as an error indication */
+ ++ppp->stats.rx_length_errors;
+
+ kfree_skb(skb);
+ ppp_receive_error(ppp);
+}
+
+static void
+ppp_receive_error(struct ppp *ppp)
+{
+ ++ppp->stats.rx_errors;
+ if (ppp->vj != 0)
+ slhc_toss(ppp->vj);
+}
+
+static void
+ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
+{
+ struct sk_buff *ns;
+ int proto, len, npi;
+
+ /*
+ * Decompress the frame, if compressed.
+ * Note that some decompressors need to see uncompressed frames
+ * that come in as well as compressed frames.
+ */
+ if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
+ && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
+ skb = ppp_decompress_frame(ppp, skb);
+
+ proto = PPP_PROTO(skb);
+ switch (proto) {
+ case PPP_VJC_COMP:
+ /* decompress VJ compressed packets */
+ if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
+ goto err;
+
+ if (skb_tailroom(skb) < 124) {
+ /* copy to a new sk_buff with more tailroom */
+ ns = dev_alloc_skb(skb->len + 128);
+ if (ns == 0) {
+ printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
+ goto err;
+ }
+ skb_reserve(ns, 2);
+ skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
+ kfree_skb(skb);
+ skb = ns;
+ }
+ else if (!pskb_may_pull(skb, skb->len))
+ goto err;
+
+ len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
+ if (len <= 0) {
+ printk(KERN_DEBUG "PPP: VJ decompression error\n");
+ goto err;
+ }
+ len += 2;
+ if (len > skb->len)
+ skb_put(skb, len - skb->len);
+ else if (len < skb->len)
+ skb_trim(skb, len);
+ proto = PPP_IP;
+ break;
+
+ case PPP_VJC_UNCOMP:
+ if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
+ goto err;
+
+ /* Until we fix the decompressor need to make sure
+ * data portion is linear.
+ */
+ if (!pskb_may_pull(skb, skb->len))
+ goto err;
+
+ if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
+ printk(KERN_ERR "PPP: VJ uncompressed error\n");
+ goto err;
+ }
+ proto = PPP_IP;
+ break;
+
+ case PPP_CCP:
+ ppp_ccp_peek(ppp, skb, 1);
+ break;
+ }
+
+ ++ppp->stats.rx_packets;
+ ppp->stats.rx_bytes += skb->len - 2;
+
+ npi = proto_to_npindex(proto);
+ if (npi < 0) {
+ /* control or unknown frame - pass it to pppd */
+ skb_queue_tail(&ppp->file.rq, skb);
+ /* limit queue length by dropping old frames */
+ while (ppp->file.rq.qlen > PPP_MAX_RQLEN
+ && (skb = skb_dequeue(&ppp->file.rq)) != 0)
+ kfree_skb(skb);
+ /* wake up any process polling or blocking on read */
+ wake_up_interruptible(&ppp->file.rwait);
+
+ } else {
+ /* network protocol frame - give it to the kernel */
+
+#ifdef CONFIG_PPP_FILTER
+ /* check if the packet passes the pass and active filters */
+ /* the filter instructions are constructed assuming
+ a four-byte PPP header on each packet */
+ *skb_push(skb, 2) = 0;
+ if (ppp->pass_filter
+ && sk_run_filter(skb, ppp->pass_filter,
+ ppp->pass_len) == 0) {
+ if (ppp->debug & 1)
+ printk(KERN_DEBUG "PPP: inbound frame not passed\n");
+ kfree_skb(skb);
+ return;
+ }
+ if (!(ppp->active_filter
+ && sk_run_filter(skb, ppp->active_filter,
+ ppp->active_len) == 0))
+ ppp->last_recv = jiffies;
+ skb_pull(skb, 2);
+#else
+ ppp->last_recv = jiffies;
+#endif /* CONFIG_PPP_FILTER */
+
+ if ((ppp->dev->flags & IFF_UP) == 0
+ || ppp->npmode[npi] != NPMODE_PASS) {
+ kfree_skb(skb);
+ } else {
+ skb_pull(skb, 2); /* chop off protocol */
+ skb->dev = ppp->dev;
+ skb->protocol = htons(npindex_to_ethertype[npi]);
+ skb->mac.raw = skb->data;
+ skb->input_dev = ppp->dev;
+ netif_rx(skb);
+ ppp->dev->last_rx = jiffies;
+ }
+ }
+ return;
+
+ err:
+ kfree_skb(skb);
+ ppp_receive_error(ppp);
+}
+
+static struct sk_buff *
+ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
+{
+ int proto = PPP_PROTO(skb);
+ struct sk_buff *ns;
+ int len;
+
+ /* Until we fix all the decompressor's need to make sure
+ * data portion is linear.
+ */
+ if (!pskb_may_pull(skb, skb->len))
+ goto err;
+
+ if (proto == PPP_COMP) {
+ ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
+ if (ns == 0) {
+ printk(KERN_ERR "ppp_decompress_frame: no memory\n");
+ goto err;
+ }
+ /* the decompressor still expects the A/C bytes in the hdr */
+ len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
+ skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
+ if (len < 0) {
+ /* Pass the compressed frame to pppd as an
+ error indication. */
+ if (len == DECOMP_FATALERROR)
+ ppp->rstate |= SC_DC_FERROR;
+ kfree_skb(ns);
+ goto err;
+ }
+
+ kfree_skb(skb);
+ skb = ns;
+ skb_put(skb, len);
+ skb_pull(skb, 2); /* pull off the A/C bytes */
+
+ } else {
+ /* Uncompressed frame - pass to decompressor so it
+ can update its dictionary if necessary. */
+ if (ppp->rcomp->incomp)
+ ppp->rcomp->incomp(ppp->rc_state, skb->data - 2,
+ skb->len + 2);
+ }
+
+ return skb;
+
+ err:
+ ppp->rstate |= SC_DC_ERROR;
+ ppp_receive_error(ppp);
+ return skb;
+}
+
+#ifdef CONFIG_PPP_MULTILINK
+/*
+ * Receive a multilink frame.
+ * We put it on the reconstruction queue and then pull off
+ * as many completed frames as we can.
+ */
+static void
+ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
+{
+ u32 mask, seq;
+ struct list_head *l;
+ int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
+
+ if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
+ goto err; /* no good, throw it away */
+
+ /* Decode sequence number and begin/end bits */
+ if (ppp->flags & SC_MP_SHORTSEQ) {
+ seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3];
+ mask = 0xfff;
+ } else {
+ seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
+ mask = 0xffffff;
+ }
+ skb->BEbits = skb->data[2];
+ skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
+
+ /*
+ * Do protocol ID decompression on the first fragment of each packet.
+ */
+ if ((skb->BEbits & B) && (skb->data[0] & 1))
+ *skb_push(skb, 1) = 0;
+
+ /*
+ * Expand sequence number to 32 bits, making it as close
+ * as possible to ppp->minseq.
+ */
+ seq |= ppp->minseq & ~mask;
+ if ((int)(ppp->minseq - seq) > (int)(mask >> 1))
+ seq += mask + 1;
+ else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
+ seq -= mask + 1; /* should never happen */
+ skb->sequence = seq;
+ pch->lastseq = seq;
+
+ /*
+ * If this packet comes before the next one we were expecting,
+ * drop it.
+ */
+ if (seq_before(seq, ppp->nextseq)) {
+ kfree_skb(skb);
+ ++ppp->stats.rx_dropped;
+ ppp_receive_error(ppp);
+ return;
+ }
+
+ /*
+ * Reevaluate minseq, the minimum over all channels of the
+ * last sequence number received on each channel. Because of
+ * the increasing sequence number rule, we know that any fragment
+ * before `minseq' which hasn't arrived is never going to arrive.
+ * The list of channels can't change because we have the receive
+ * side of the ppp unit locked.
+ */
+ for (l = ppp->channels.next; l != &ppp->channels; l = l->next) {
+ struct channel *ch = list_entry(l, struct channel, clist);
+ if (seq_before(ch->lastseq, seq))
+ seq = ch->lastseq;
+ }
+ if (seq_before(ppp->minseq, seq))
+ ppp->minseq = seq;
+
+ /* Put the fragment on the reconstruction queue */
+ ppp_mp_insert(ppp, skb);
+
+ /* If the queue is getting long, don't wait any longer for packets
+ before the start of the queue. */
+ if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN
+ && seq_before(ppp->minseq, ppp->mrq.next->sequence))
+ ppp->minseq = ppp->mrq.next->sequence;
+
+ /* Pull completed packets off the queue and receive them. */
+ while ((skb = ppp_mp_reconstruct(ppp)) != 0)
+ ppp_receive_nonmp_frame(ppp, skb);
+
+ return;
+
+ err:
+ kfree_skb(skb);
+ ppp_receive_error(ppp);
+}
+
+/*
+ * Insert a fragment on the MP reconstruction queue.
+ * The queue is ordered by increasing sequence number.
+ */
+static void
+ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
+{
+ struct sk_buff *p;
+ struct sk_buff_head *list = &ppp->mrq;
+ u32 seq = skb->sequence;
+
+ /* N.B. we don't need to lock the list lock because we have the
+ ppp unit receive-side lock. */
+ for (p = list->next; p != (struct sk_buff *)list; p = p->next)
+ if (seq_before(seq, p->sequence))
+ break;
+ __skb_insert(skb, p->prev, p, list);
+}
+
+/*
+ * Reconstruct a packet from the MP fragment queue.
+ * We go through increasing sequence numbers until we find a
+ * complete packet, or we get to the sequence number for a fragment
+ * which hasn't arrived but might still do so.
+ */
+struct sk_buff *
+ppp_mp_reconstruct(struct ppp *ppp)
+{
+ u32 seq = ppp->nextseq;
+ u32 minseq = ppp->minseq;
+ struct sk_buff_head *list = &ppp->mrq;
+ struct sk_buff *p, *next;
+ struct sk_buff *head, *tail;
+ struct sk_buff *skb = NULL;
+ int lost = 0, len = 0;
+
+ if (ppp->mrru == 0) /* do nothing until mrru is set */
+ return NULL;
+ head = list->next;
+ tail = NULL;
+ for (p = head; p != (struct sk_buff *) list; p = next) {
+ next = p->next;
+ if (seq_before(p->sequence, seq)) {
+ /* this can't happen, anyway ignore the skb */
+ printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
+ p->sequence, seq);
+ head = next;
+ continue;
+ }
+ if (p->sequence != seq) {
+ /* Fragment `seq' is missing. If it is after
+ minseq, it might arrive later, so stop here. */
+ if (seq_after(seq, minseq))
+ break;
+ /* Fragment `seq' is lost, keep going. */
+ lost = 1;
+ seq = seq_before(minseq, p->sequence)?
+ minseq + 1: p->sequence;
+ next = p;
+ continue;
+ }
+
+ /*
+ * At this point we know that all the fragments from
+ * ppp->nextseq to seq are either present or lost.
+ * Also, there are no complete packets in the queue
+ * that have no missing fragments and end before this
+ * fragment.
+ */
+
+ /* B bit set indicates this fragment starts a packet */
+ if (p->BEbits & B) {
+ head = p;
+ lost = 0;
+ len = 0;
+ }
+
+ len += p->len;
+
+ /* Got a complete packet yet? */
+ if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
+ if (len > ppp->mrru + 2) {
+ ++ppp->stats.rx_length_errors;
+ printk(KERN_DEBUG "PPP: reconstructed packet"
+ " is too long (%d)\n", len);
+ } else if (p == head) {
+ /* fragment is complete packet - reuse skb */
+ tail = p;
+ skb = skb_get(p);
+ break;
+ } else if ((skb = dev_alloc_skb(len)) == NULL) {
+ ++ppp->stats.rx_missed_errors;
+ printk(KERN_DEBUG "PPP: no memory for "
+ "reconstructed packet");
+ } else {
+ tail = p;
+ break;
+ }
+ ppp->nextseq = seq + 1;
+ }
+
+ /*
+ * If this is the ending fragment of a packet,
+ * and we haven't found a complete valid packet yet,
+ * we can discard up to and including this fragment.
+ */
+ if (p->BEbits & E)
+ head = next;
+
+ ++seq;
+ }
+
+ /* If we have a complete packet, copy it all into one skb. */
+ if (tail != NULL) {
+ /* If we have discarded any fragments,
+ signal a receive error. */
+ if (head->sequence != ppp->nextseq) {
+ if (ppp->debug & 1)
+ printk(KERN_DEBUG " missed pkts %u..%u\n",
+ ppp->nextseq, head->sequence-1);
+ ++ppp->stats.rx_dropped;
+ ppp_receive_error(ppp);
+ }
+
+ if (head != tail)
+ /* copy to a single skb */
+ for (p = head; p != tail->next; p = p->next)
+ skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
+ ppp->nextseq = tail->sequence + 1;
+ head = tail->next;
+ }
+
+ /* Discard all the skbuffs that we have copied the data out of
+ or that we can't use. */
+ while ((p = list->next) != head) {
+ __skb_unlink(p, list);
+ kfree_skb(p);
+ }
+
+ return skb;
+}
+#endif /* CONFIG_PPP_MULTILINK */
+
+/*
+ * Channel interface.
+ */
+
+/*
+ * Create a new, unattached ppp channel.
+ */
+int
+ppp_register_channel(struct ppp_channel *chan)
+{
+ struct channel *pch;
+
+ pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
+ if (pch == 0)
+ return -ENOMEM;
+ memset(pch, 0, sizeof(struct channel));
+ pch->ppp = NULL;
+ pch->chan = chan;
+ chan->ppp = pch;
+ init_ppp_file(&pch->file, CHANNEL);
+ pch->file.hdrlen = chan->hdrlen;
+#ifdef CONFIG_PPP_MULTILINK
+ pch->lastseq = -1;
+#endif /* CONFIG_PPP_MULTILINK */
+ init_rwsem(&pch->chan_sem);
+ spin_lock_init(&pch->downl);
+ rwlock_init(&pch->upl);
+ spin_lock_bh(&all_channels_lock);
+ pch->file.index = ++last_channel_index;
+ list_add(&pch->list, &new_channels);
+ atomic_inc(&channel_count);
+ spin_unlock_bh(&all_channels_lock);
+ return 0;
+}
+
+/*
+ * Return the index of a channel.
+ */
+int ppp_channel_index(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+
+ if (pch != 0)
+ return pch->file.index;
+ return -1;
+}
+
+/*
+ * Return the PPP unit number to which a channel is connected.
+ */
+int ppp_unit_number(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+ int unit = -1;
+
+ if (pch != 0) {
+ read_lock_bh(&pch->upl);
+ if (pch->ppp != 0)
+ unit = pch->ppp->file.index;
+ read_unlock_bh(&pch->upl);
+ }
+ return unit;
+}
+
+/*
+ * Disconnect a channel from the generic layer.
+ * This must be called in process context.
+ */
+void
+ppp_unregister_channel(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+
+ if (pch == 0)
+ return; /* should never happen */
+ chan->ppp = NULL;
+
+ /*
+ * This ensures that we have returned from any calls into the
+ * the channel's start_xmit or ioctl routine before we proceed.
+ */
+ down_write(&pch->chan_sem);
+ spin_lock_bh(&pch->downl);
+ pch->chan = NULL;
+ spin_unlock_bh(&pch->downl);
+ up_write(&pch->chan_sem);
+ ppp_disconnect_channel(pch);
+ spin_lock_bh(&all_channels_lock);
+ list_del(&pch->list);
+ spin_unlock_bh(&all_channels_lock);
+ pch->file.dead = 1;
+ wake_up_interruptible(&pch->file.rwait);
+ if (atomic_dec_and_test(&pch->file.refcnt))
+ ppp_destroy_channel(pch);
+}
+
+/*
+ * Callback from a channel when it can accept more to transmit.
+ * This should be called at BH/softirq level, not interrupt level.
+ */
+void
+ppp_output_wakeup(struct ppp_channel *chan)
+{
+ struct channel *pch = chan->ppp;
+
+ if (pch == 0)
+ return;
+ ppp_channel_push(pch);
+}
+
+/*
+ * Compression control.
+ */
+
+/* Process the PPPIOCSCOMPRESS ioctl. */
+static int
+ppp_set_compress(struct ppp *ppp, unsigned long arg)
+{
+ int err;
+ struct compressor *cp, *ocomp;
+ struct ppp_option_data data;
+ void *state, *ostate;
+ unsigned char ccp_option[CCP_MAX_OPTION_LENGTH];
+
+ err = -EFAULT;
+ if (copy_from_user(&data, (void __user *) arg, sizeof(data))
+ || (data.length <= CCP_MAX_OPTION_LENGTH
+ && copy_from_user(ccp_option, (void __user *) data.ptr, data.length)))
+ goto out;
+ err = -EINVAL;
+ if (data.length > CCP_MAX_OPTION_LENGTH
+ || ccp_option[1] < 2 || ccp_option[1] > data.length)
+ goto out;
+
+ cp = find_compressor(ccp_option[0]);
+#ifdef CONFIG_KMOD
+ if (cp == 0) {
+ request_module("ppp-compress-%d", ccp_option[0]);
+ cp = find_compressor(ccp_option[0]);
+ }
+#endif /* CONFIG_KMOD */
+ if (cp == 0)
+ goto out;
+
+ err = -ENOBUFS;
+ if (data.transmit) {
+ state = cp->comp_alloc(ccp_option, data.length);
+ if (state != 0) {
+ ppp_xmit_lock(ppp);
+ ppp->xstate &= ~SC_COMP_RUN;
+ ocomp = ppp->xcomp;
+ ostate = ppp->xc_state;
+ ppp->xcomp = cp;
+ ppp->xc_state = state;
+ ppp_xmit_unlock(ppp);
+ if (ostate != 0) {
+ ocomp->comp_free(ostate);
+ module_put(ocomp->owner);
+ }
+ err = 0;
+ } else
+ module_put(cp->owner);
+
+ } else {
+ state = cp->decomp_alloc(ccp_option, data.length);
+ if (state != 0) {
+ ppp_recv_lock(ppp);
+ ppp->rstate &= ~SC_DECOMP_RUN;
+ ocomp = ppp->rcomp;
+ ostate = ppp->rc_state;
+ ppp->rcomp = cp;
+ ppp->rc_state = state;
+ ppp_recv_unlock(ppp);
+ if (ostate != 0) {
+ ocomp->decomp_free(ostate);
+ module_put(ocomp->owner);
+ }
+ err = 0;
+ } else
+ module_put(cp->owner);
+ }
+
+ out:
+ return err;
+}
+
+/*
+ * Look at a CCP packet and update our state accordingly.
+ * We assume the caller has the xmit or recv path locked.
+ */
+static void
+ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
+{
+ unsigned char *dp;
+ int len;
+
+ if (!pskb_may_pull(skb, CCP_HDRLEN + 2))
+ return; /* no header */
+ dp = skb->data + 2;
+
+ switch (CCP_CODE(dp)) {
+ case CCP_CONFREQ:
+
+ /* A ConfReq starts negotiation of compression
+ * in one direction of transmission,
+ * and hence brings it down...but which way?
+ *
+ * Remember:
+ * A ConfReq indicates what the sender would like to receive
+ */
+ if(inbound)
+ /* He is proposing what I should send */
+ ppp->xstate &= ~SC_COMP_RUN;
+ else
+ /* I am proposing to what he should send */
+ ppp->rstate &= ~SC_DECOMP_RUN;
+
+ break;
+
+ case CCP_TERMREQ:
+ case CCP_TERMACK:
+ /*
+ * CCP is going down, both directions of transmission
+ */
+ ppp->rstate &= ~SC_DECOMP_RUN;
+ ppp->xstate &= ~SC_COMP_RUN;
+ break;
+
+ case CCP_CONFACK:
+ if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN)
+ break;
+ len = CCP_LENGTH(dp);
+ if (!pskb_may_pull(skb, len + 2))
+ return; /* too short */
+ dp += CCP_HDRLEN;
+ len -= CCP_HDRLEN;
+ if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp))
+ break;
+ if (inbound) {
+ /* we will start receiving compressed packets */
+ if (ppp->rc_state == 0)
+ break;
+ if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
+ ppp->file.index, 0, ppp->mru, ppp->debug)) {
+ ppp->rstate |= SC_DECOMP_RUN;
+ ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR);
+ }
+ } else {
+ /* we will soon start sending compressed packets */
+ if (ppp->xc_state == 0)
+ break;
+ if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
+ ppp->file.index, 0, ppp->debug))
+ ppp->xstate |= SC_COMP_RUN;
+ }
+ break;
+
+ case CCP_RESETACK:
+ /* reset the [de]compressor */
+ if ((ppp->flags & SC_CCP_UP) == 0)
+ break;
+ if (inbound) {
+ if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) {
+ ppp->rcomp->decomp_reset(ppp->rc_state);
+ ppp->rstate &= ~SC_DC_ERROR;
+ }
+ } else {
+ if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN))
+ ppp->xcomp->comp_reset(ppp->xc_state);
+ }
+ break;
+ }
+}
+
+/* Free up compression resources. */
+static void
+ppp_ccp_closed(struct ppp *ppp)
+{
+ void *xstate, *rstate;
+ struct compressor *xcomp, *rcomp;
+
+ ppp_lock(ppp);
+ ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP);
+ ppp->xstate = 0;
+ xcomp = ppp->xcomp;
+ xstate = ppp->xc_state;
+ ppp->xc_state = NULL;
+ ppp->rstate = 0;
+ rcomp = ppp->rcomp;
+ rstate = ppp->rc_state;
+ ppp->rc_state = NULL;
+ ppp_unlock(ppp);
+
+ if (xstate) {
+ xcomp->comp_free(xstate);
+ module_put(xcomp->owner);
+ }
+ if (rstate) {
+ rcomp->decomp_free(rstate);
+ module_put(rcomp->owner);
+ }
+}
+
+/* List of compressors. */
+static LIST_HEAD(compressor_list);
+static DEFINE_SPINLOCK(compressor_list_lock);
+
+struct compressor_entry {
+ struct list_head list;
+ struct compressor *comp;
+};
+
+static struct compressor_entry *
+find_comp_entry(int proto)
+{
+ struct compressor_entry *ce;
+ struct list_head *list = &compressor_list;
+
+ while ((list = list->next) != &compressor_list) {
+ ce = list_entry(list, struct compressor_entry, list);
+ if (ce->comp->compress_proto == proto)
+ return ce;
+ }
+ return NULL;
+}
+
+/* Register a compressor */
+int
+ppp_register_compressor(struct compressor *cp)
+{
+ struct compressor_entry *ce;
+ int ret;
+ spin_lock(&compressor_list_lock);
+ ret = -EEXIST;
+ if (find_comp_entry(cp->compress_proto) != 0)
+ goto out;
+ ret = -ENOMEM;
+ ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
+ if (ce == 0)
+ goto out;
+ ret = 0;
+ ce->comp = cp;
+ list_add(&ce->list, &compressor_list);
+ out:
+ spin_unlock(&compressor_list_lock);
+ return ret;
+}
+
+/* Unregister a compressor */
+void
+ppp_unregister_compressor(struct compressor *cp)
+{
+ struct compressor_entry *ce;
+
+ spin_lock(&compressor_list_lock);
+ ce = find_comp_entry(cp->compress_proto);
+ if (ce != 0 && ce->comp == cp) {
+ list_del(&ce->list);
+ kfree(ce);
+ }
+ spin_unlock(&compressor_list_lock);
+}
+
+/* Find a compressor. */
+static struct compressor *
+find_compressor(int type)
+{
+ struct compressor_entry *ce;
+ struct compressor *cp = NULL;
+
+ spin_lock(&compressor_list_lock);
+ ce = find_comp_entry(type);
+ if (ce != 0) {
+ cp = ce->comp;
+ if (!try_module_get(cp->owner))
+ cp = NULL;
+ }
+ spin_unlock(&compressor_list_lock);
+ return cp;
+}
+
+/*
+ * Miscelleneous stuff.
+ */
+
+static void
+ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
+{
+ struct slcompress *vj = ppp->vj;
+
+ memset(st, 0, sizeof(*st));
+ st->p.ppp_ipackets = ppp->stats.rx_packets;
+ st->p.ppp_ierrors = ppp->stats.rx_errors;
+ st->p.ppp_ibytes = ppp->stats.rx_bytes;
+ st->p.ppp_opackets = ppp->stats.tx_packets;
+ st->p.ppp_oerrors = ppp->stats.tx_errors;
+ st->p.ppp_obytes = ppp->stats.tx_bytes;
+ if (vj == 0)
+ return;
+ st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
+ st->vj.vjs_compressed = vj->sls_o_compressed;
+ st->vj.vjs_searches = vj->sls_o_searches;
+ st->vj.vjs_misses = vj->sls_o_misses;
+ st->vj.vjs_errorin = vj->sls_i_error;
+ st->vj.vjs_tossed = vj->sls_i_tossed;
+ st->vj.vjs_uncompressedin = vj->sls_i_uncompressed;
+ st->vj.vjs_compressedin = vj->sls_i_compressed;
+}
+
+/*
+ * Stuff for handling the lists of ppp units and channels
+ * and for initialization.
+ */
+
+/*
+ * Create a new ppp interface unit. Fails if it can't allocate memory
+ * or if there is already a unit with the requested number.
+ * unit == -1 means allocate a new number.
+ */
+static struct ppp *
+ppp_create_interface(int unit, int *retp)
+{
+ struct ppp *ppp;
+ struct net_device *dev = NULL;
+ int ret = -ENOMEM;
+ int i;
+
+ ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
+ if (!ppp)
+ goto out;
+ dev = alloc_netdev(0, "", ppp_setup);
+ if (!dev)
+ goto out1;
+ memset(ppp, 0, sizeof(struct ppp));
+
+ ppp->mru = PPP_MRU;
+ init_ppp_file(&ppp->file, INTERFACE);
+ ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */
+ for (i = 0; i < NUM_NP; ++i)
+ ppp->npmode[i] = NPMODE_PASS;
+ INIT_LIST_HEAD(&ppp->channels);
+ spin_lock_init(&ppp->rlock);
+ spin_lock_init(&ppp->wlock);
+#ifdef CONFIG_PPP_MULTILINK
+ ppp->minseq = -1;
+ skb_queue_head_init(&ppp->mrq);
+#endif /* CONFIG_PPP_MULTILINK */
+ ppp->dev = dev;
+ dev->priv = ppp;
+
+ dev->hard_start_xmit = ppp_start_xmit;
+ dev->get_stats = ppp_net_stats;
+ dev->do_ioctl = ppp_net_ioctl;
+
+ ret = -EEXIST;
+ down(&all_ppp_sem);
+ if (unit < 0)
+ unit = cardmap_find_first_free(all_ppp_units);
+ else if (cardmap_get(all_ppp_units, unit) != NULL)
+ goto out2; /* unit already exists */
+
+ /* Initialize the new ppp unit */
+ ppp->file.index = unit;
+ sprintf(dev->name, "ppp%d", unit);
+
+ ret = register_netdev(dev);
+ if (ret != 0) {
+ printk(KERN_ERR "PPP: couldn't register device %s (%d)\n",
+ dev->name, ret);
+ goto out2;
+ }
+
+ atomic_inc(&ppp_unit_count);
+ cardmap_set(&all_ppp_units, unit, ppp);
+ up(&all_ppp_sem);
+ *retp = 0;
+ return ppp;
+
+out2:
+ up(&all_ppp_sem);
+ free_netdev(dev);
+out1:
+ kfree(ppp);
+out:
+ *retp = ret;
+ return NULL;
+}
+
+/*
+ * Initialize a ppp_file structure.
+ */
+static void
+init_ppp_file(struct ppp_file *pf, int kind)
+{
+ pf->kind = kind;
+ skb_queue_head_init(&pf->xq);
+ skb_queue_head_init(&pf->rq);
+ atomic_set(&pf->refcnt, 1);
+ init_waitqueue_head(&pf->rwait);
+}
+
+/*
+ * Take down a ppp interface unit - called when the owning file
+ * (the one that created the unit) is closed or detached.
+ */
+static void ppp_shutdown_interface(struct ppp *ppp)
+{
+ struct net_device *dev;
+
+ down(&all_ppp_sem);
+ ppp_lock(ppp);
+ dev = ppp->dev;
+ ppp->dev = NULL;
+ ppp_unlock(ppp);
+ /* This will call dev_close() for us. */
+ if (dev) {
+ unregister_netdev(dev);
+ free_netdev(dev);
+ }
+ cardmap_set(&all_ppp_units, ppp->file.index, NULL);
+ ppp->file.dead = 1;
+ ppp->owner = NULL;
+ wake_up_interruptible(&ppp->file.rwait);
+ up(&all_ppp_sem);
+}
+
+/*
+ * Free the memory used by a ppp unit. This is only called once
+ * there are no channels connected to the unit and no file structs
+ * that reference the unit.
+ */
+static void ppp_destroy_interface(struct ppp *ppp)
+{
+ atomic_dec(&ppp_unit_count);
+
+ if (!ppp->file.dead || ppp->n_channels) {
+ /* "can't happen" */
+ printk(KERN_ERR "ppp: destroying ppp struct %p but dead=%d "
+ "n_channels=%d !\n", ppp, ppp->file.dead,
+ ppp->n_channels);
+ return;
+ }
+
+ ppp_ccp_closed(ppp);
+ if (ppp->vj) {
+ slhc_free(ppp->vj);
+ ppp->vj = NULL;
+ }
+ skb_queue_purge(&ppp->file.xq);
+ skb_queue_purge(&ppp->file.rq);
+#ifdef CONFIG_PPP_MULTILINK
+ skb_queue_purge(&ppp->mrq);
+#endif /* CONFIG_PPP_MULTILINK */
+#ifdef CONFIG_PPP_FILTER
+ if (ppp->pass_filter) {
+ kfree(ppp->pass_filter);
+ ppp->pass_filter = NULL;
+ }
+ if (ppp->active_filter) {
+ kfree(ppp->active_filter);
+ ppp->active_filter = NULL;
+ }
+#endif /* CONFIG_PPP_FILTER */
+
+ kfree(ppp);
+}
+
+/*
+ * Locate an existing ppp unit.
+ * The caller should have locked the all_ppp_sem.
+ */
+static struct ppp *
+ppp_find_unit(int unit)
+{
+ return cardmap_get(all_ppp_units, unit);
+}
+
+/*
+ * Locate an existing ppp channel.
+ * The caller should have locked the all_channels_lock.
+ * First we look in the new_channels list, then in the
+ * all_channels list. If found in the new_channels list,
+ * we move it to the all_channels list. This is for speed
+ * when we have a lot of channels in use.
+ */
+static struct channel *
+ppp_find_channel(int unit)
+{
+ struct channel *pch;
+ struct list_head *list;
+
+ list = &new_channels;
+ while ((list = list->next) != &new_channels) {
+ pch = list_entry(list, struct channel, list);
+ if (pch->file.index == unit) {
+ list_del(&pch->list);
+ list_add(&pch->list, &all_channels);
+ return pch;
+ }
+ }
+ list = &all_channels;
+ while ((list = list->next) != &all_channels) {
+ pch = list_entry(list, struct channel, list);
+ if (pch->file.index == unit)
+ return pch;
+ }
+ return NULL;
+}
+
+/*
+ * Connect a PPP channel to a PPP interface unit.
+ */
+static int
+ppp_connect_channel(struct channel *pch, int unit)
+{
+ struct ppp *ppp;
+ int ret = -ENXIO;
+ int hdrlen;
+
+ down(&all_ppp_sem);
+ ppp = ppp_find_unit(unit);
+ if (ppp == 0)
+ goto out;
+ write_lock_bh(&pch->upl);
+ ret = -EINVAL;
+ if (pch->ppp != 0)
+ goto outl;
+
+ ppp_lock(ppp);
+ if (pch->file.hdrlen > ppp->file.hdrlen)
+ ppp->file.hdrlen = pch->file.hdrlen;
+ hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
+ if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
+ ppp->dev->hard_header_len = hdrlen;
+ list_add_tail(&pch->clist, &ppp->channels);
+ ++ppp->n_channels;
+ pch->ppp = ppp;
+ atomic_inc(&ppp->file.refcnt);
+ ppp_unlock(ppp);
+ ret = 0;
+
+ outl:
+ write_unlock_bh(&pch->upl);
+ out:
+ up(&all_ppp_sem);
+ return ret;
+}
+
+/*
+ * Disconnect a channel from its ppp unit.
+ */
+static int
+ppp_disconnect_channel(struct channel *pch)
+{
+ struct ppp *ppp;
+ int err = -EINVAL;
+
+ write_lock_bh(&pch->upl);
+ ppp = pch->ppp;
+ pch->ppp = NULL;
+ write_unlock_bh(&pch->upl);
+ if (ppp != 0) {
+ /* remove it from the ppp unit's list */
+ ppp_lock(ppp);
+ list_del(&pch->clist);
+ if (--ppp->n_channels == 0)
+ wake_up_interruptible(&ppp->file.rwait);
+ ppp_unlock(ppp);
+ if (atomic_dec_and_test(&ppp->file.refcnt))
+ ppp_destroy_interface(ppp);
+ err = 0;
+ }
+ return err;
+}
+
+/*
+ * Free up the resources used by a ppp channel.
+ */
+static void ppp_destroy_channel(struct channel *pch)
+{
+ atomic_dec(&channel_count);
+
+ if (!pch->file.dead) {
+ /* "can't happen" */
+ printk(KERN_ERR "ppp: destroying undead channel %p !\n",
+ pch);
+ return;
+ }
+ skb_queue_purge(&pch->file.xq);
+ skb_queue_purge(&pch->file.rq);
+ kfree(pch);
+}
+
+static void __exit ppp_cleanup(void)
+{
+ /* should never happen */
+ if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
+ printk(KERN_ERR "PPP: removing module but units remain!\n");
+ cardmap_destroy(&all_ppp_units);
+ if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
+ printk(KERN_ERR "PPP: failed to unregister PPP device\n");
+ devfs_remove("ppp");
+ class_simple_device_remove(MKDEV(PPP_MAJOR, 0));
+ class_simple_destroy(ppp_class);
+}
+
+/*
+ * Cardmap implementation.
+ */
+static void *cardmap_get(struct cardmap *map, unsigned int nr)
+{
+ struct cardmap *p;
+ int i;
+
+ for (p = map; p != NULL; ) {
+ if ((i = nr >> p->shift) >= CARDMAP_WIDTH)
+ return NULL;
+ if (p->shift == 0)
+ return p->ptr[i];
+ nr &= ~(CARDMAP_MASK << p->shift);
+ p = p->ptr[i];
+ }
+ return NULL;
+}
+
+static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
+{
+ struct cardmap *p;
+ int i;
+
+ p = *pmap;
+ if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
+ do {
+ /* need a new top level */
+ struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
+ memset(np, 0, sizeof(*np));
+ np->ptr[0] = p;
+ if (p != NULL) {
+ np->shift = p->shift + CARDMAP_ORDER;
+ p->parent = np;
+ } else
+ np->shift = 0;
+ p = np;
+ } while ((nr >> p->shift) >= CARDMAP_WIDTH);
+ *pmap = p;
+ }
+ while (p->shift > 0) {
+ i = (nr >> p->shift) & CARDMAP_MASK;
+ if (p->ptr[i] == NULL) {
+ struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
+ memset(np, 0, sizeof(*np));
+ np->shift = p->shift - CARDMAP_ORDER;
+ np->parent = p;
+ p->ptr[i] = np;
+ }
+ if (ptr == NULL)
+ clear_bit(i, &p->inuse);
+ p = p->ptr[i];
+ }
+ i = nr & CARDMAP_MASK;
+ p->ptr[i] = ptr;
+ if (ptr != NULL)
+ set_bit(i, &p->inuse);
+ else
+ clear_bit(i, &p->inuse);
+}
+
+static unsigned int cardmap_find_first_free(struct cardmap *map)
+{
+ struct cardmap *p;
+ unsigned int nr = 0;
+ int i;
+
+ if ((p = map) == NULL)
+ return 0;
+ for (;;) {
+ i = find_first_zero_bit(&p->inuse, CARDMAP_WIDTH);
+ if (i >= CARDMAP_WIDTH) {
+ if (p->parent == NULL)
+ return CARDMAP_WIDTH << p->shift;
+ p = p->parent;
+ i = (nr >> p->shift) & CARDMAP_MASK;
+ set_bit(i, &p->inuse);
+ continue;
+ }
+ nr = (nr & (~CARDMAP_MASK << p->shift)) | (i << p->shift);
+ if (p->shift == 0 || p->ptr[i] == NULL)
+ return nr;
+ p = p->ptr[i];
+ }
+}
+
+static void cardmap_destroy(struct cardmap **pmap)
+{
+ struct cardmap *p, *np;
+ int i;
+
+ for (p = *pmap; p != NULL; p = np) {
+ if (p->shift != 0) {
+ for (i = 0; i < CARDMAP_WIDTH; ++i)
+ if (p->ptr[i] != NULL)
+ break;
+ if (i < CARDMAP_WIDTH) {
+ np = p->ptr[i];
+ p->ptr[i] = NULL;
+ continue;
+ }
+ }
+ np = p->parent;
+ kfree(p);
+ }
+ *pmap = NULL;
+}
+
+/* Module/initialization stuff */
+
+module_init(ppp_init);
+module_exit(ppp_cleanup);
+
+EXPORT_SYMBOL(ppp_register_channel);
+EXPORT_SYMBOL(ppp_unregister_channel);
+EXPORT_SYMBOL(ppp_channel_index);
+EXPORT_SYMBOL(ppp_unit_number);
+EXPORT_SYMBOL(ppp_input);
+EXPORT_SYMBOL(ppp_input_error);
+EXPORT_SYMBOL(ppp_output_wakeup);
+EXPORT_SYMBOL(ppp_register_compressor);
+EXPORT_SYMBOL(ppp_unregister_compressor);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(PPP_MAJOR);
+MODULE_ALIAS("/dev/ppp");
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.