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authorJeff Kirsher <jeffrey.t.kirsher@intel.com>2011-07-31 13:38:19 +0400
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2011-08-27 11:58:26 +0400
commit224cf5ad14c038b13c119dff29422f178a306f54 (patch)
tree89bf411ea743e9d7bbd3c609eeb7220270a97fc5 /drivers/net/ppp_async.c
parentaab3ac26108642eaa06efa4697dab595c7de2bbd (diff)
downloadlinux-224cf5ad14c038b13c119dff29422f178a306f54.tar.xz
ppp: Move the PPP drivers
Move the PPP drivers into drivers/net/ppp/ and make the necessary Kconfig and Makefile changes. CC: Paul Mackerras <paulus@samba.org> CC: Frank Cusack <fcusack@fcusack.com> CC: Michal Ostrowski <mostrows@speakeasy.net> CC: Michal Ostrowski <mostrows@earthlink.net> CC: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ppp_async.c')
-rw-r--r--drivers/net/ppp_async.c1028
1 files changed, 0 insertions, 1028 deletions
diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c
deleted file mode 100644
index c6ba64380829..000000000000
--- a/drivers/net/ppp_async.c
+++ /dev/null
@@ -1,1028 +0,0 @@
-/*
- * PPP async serial channel driver for Linux.
- *
- * Copyright 1999 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.
- *
- * This driver provides the encapsulation and framing for sending
- * and receiving PPP frames over async serial lines. It relies on
- * the generic PPP layer to give it frames to send and to process
- * received frames. It implements the PPP line discipline.
- *
- * 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.
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/skbuff.h>
-#include <linux/tty.h>
-#include <linux/netdevice.h>
-#include <linux/poll.h>
-#include <linux/crc-ccitt.h>
-#include <linux/ppp_defs.h>
-#include <linux/if_ppp.h>
-#include <linux/ppp_channel.h>
-#include <linux/spinlock.h>
-#include <linux/init.h>
-#include <linux/interrupt.h>
-#include <linux/jiffies.h>
-#include <linux/slab.h>
-#include <asm/unaligned.h>
-#include <asm/uaccess.h>
-#include <asm/string.h>
-
-#define PPP_VERSION "2.4.2"
-
-#define OBUFSIZE 4096
-
-/* Structure for storing local state. */
-struct asyncppp {
- struct tty_struct *tty;
- unsigned int flags;
- unsigned int state;
- unsigned int rbits;
- int mru;
- spinlock_t xmit_lock;
- spinlock_t recv_lock;
- unsigned long xmit_flags;
- u32 xaccm[8];
- u32 raccm;
- unsigned int bytes_sent;
- unsigned int bytes_rcvd;
-
- struct sk_buff *tpkt;
- int tpkt_pos;
- u16 tfcs;
- unsigned char *optr;
- unsigned char *olim;
- unsigned long last_xmit;
-
- struct sk_buff *rpkt;
- int lcp_fcs;
- struct sk_buff_head rqueue;
-
- struct tasklet_struct tsk;
-
- atomic_t refcnt;
- struct semaphore dead_sem;
- struct ppp_channel chan; /* interface to generic ppp layer */
- unsigned char obuf[OBUFSIZE];
-};
-
-/* Bit numbers in xmit_flags */
-#define XMIT_WAKEUP 0
-#define XMIT_FULL 1
-#define XMIT_BUSY 2
-
-/* State bits */
-#define SC_TOSS 1
-#define SC_ESCAPE 2
-#define SC_PREV_ERROR 4
-
-/* Bits in rbits */
-#define SC_RCV_BITS (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
-
-static int flag_time = HZ;
-module_param(flag_time, int, 0);
-MODULE_PARM_DESC(flag_time, "ppp_async: interval between flagged packets (in clock ticks)");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_LDISC(N_PPP);
-
-/*
- * Prototypes.
- */
-static int ppp_async_encode(struct asyncppp *ap);
-static int ppp_async_send(struct ppp_channel *chan, struct sk_buff *skb);
-static int ppp_async_push(struct asyncppp *ap);
-static void ppp_async_flush_output(struct asyncppp *ap);
-static void ppp_async_input(struct asyncppp *ap, const unsigned char *buf,
- char *flags, int count);
-static int ppp_async_ioctl(struct ppp_channel *chan, unsigned int cmd,
- unsigned long arg);
-static void ppp_async_process(unsigned long arg);
-
-static void async_lcp_peek(struct asyncppp *ap, unsigned char *data,
- int len, int inbound);
-
-static const struct ppp_channel_ops async_ops = {
- .start_xmit = ppp_async_send,
- .ioctl = ppp_async_ioctl,
-};
-
-/*
- * Routines implementing the PPP line discipline.
- */
-
-/*
- * We have a potential race on dereferencing tty->disc_data,
- * because the tty layer provides no locking at all - thus one
- * cpu could be running ppp_asynctty_receive while another
- * calls ppp_asynctty_close, which zeroes tty->disc_data and
- * frees the memory that ppp_asynctty_receive is using. The best
- * way to fix this is to use a rwlock in the tty struct, but for now
- * we use a single global rwlock for all ttys in ppp line discipline.
- *
- * FIXME: this is no longer true. The _close path for the ldisc is
- * now guaranteed to be sane.
- */
-static DEFINE_RWLOCK(disc_data_lock);
-
-static struct asyncppp *ap_get(struct tty_struct *tty)
-{
- struct asyncppp *ap;
-
- read_lock(&disc_data_lock);
- ap = tty->disc_data;
- if (ap != NULL)
- atomic_inc(&ap->refcnt);
- read_unlock(&disc_data_lock);
- return ap;
-}
-
-static void ap_put(struct asyncppp *ap)
-{
- if (atomic_dec_and_test(&ap->refcnt))
- up(&ap->dead_sem);
-}
-
-/*
- * Called when a tty is put into PPP line discipline. Called in process
- * context.
- */
-static int
-ppp_asynctty_open(struct tty_struct *tty)
-{
- struct asyncppp *ap;
- int err;
- int speed;
-
- if (tty->ops->write == NULL)
- return -EOPNOTSUPP;
-
- err = -ENOMEM;
- ap = kzalloc(sizeof(*ap), GFP_KERNEL);
- if (!ap)
- goto out;
-
- /* initialize the asyncppp structure */
- ap->tty = tty;
- ap->mru = PPP_MRU;
- spin_lock_init(&ap->xmit_lock);
- spin_lock_init(&ap->recv_lock);
- ap->xaccm[0] = ~0U;
- ap->xaccm[3] = 0x60000000U;
- ap->raccm = ~0U;
- ap->optr = ap->obuf;
- ap->olim = ap->obuf;
- ap->lcp_fcs = -1;
-
- skb_queue_head_init(&ap->rqueue);
- tasklet_init(&ap->tsk, ppp_async_process, (unsigned long) ap);
-
- atomic_set(&ap->refcnt, 1);
- sema_init(&ap->dead_sem, 0);
-
- ap->chan.private = ap;
- ap->chan.ops = &async_ops;
- ap->chan.mtu = PPP_MRU;
- speed = tty_get_baud_rate(tty);
- ap->chan.speed = speed;
- err = ppp_register_channel(&ap->chan);
- if (err)
- goto out_free;
-
- tty->disc_data = ap;
- tty->receive_room = 65536;
- return 0;
-
- out_free:
- kfree(ap);
- out:
- return err;
-}
-
-/*
- * Called when the tty is put into another line discipline
- * or it hangs up. We have to wait for any cpu currently
- * executing in any of the other ppp_asynctty_* routines to
- * finish before we can call ppp_unregister_channel and free
- * the asyncppp struct. This routine must be called from
- * process context, not interrupt or softirq context.
- */
-static void
-ppp_asynctty_close(struct tty_struct *tty)
-{
- struct asyncppp *ap;
-
- write_lock_irq(&disc_data_lock);
- ap = tty->disc_data;
- tty->disc_data = NULL;
- write_unlock_irq(&disc_data_lock);
- if (!ap)
- return;
-
- /*
- * We have now ensured that nobody can start using ap from now
- * on, but we have to wait for all existing users to finish.
- * Note that ppp_unregister_channel ensures that no calls to
- * our channel ops (i.e. ppp_async_send/ioctl) are in progress
- * by the time it returns.
- */
- if (!atomic_dec_and_test(&ap->refcnt))
- down(&ap->dead_sem);
- tasklet_kill(&ap->tsk);
-
- ppp_unregister_channel(&ap->chan);
- kfree_skb(ap->rpkt);
- skb_queue_purge(&ap->rqueue);
- kfree_skb(ap->tpkt);
- kfree(ap);
-}
-
-/*
- * Called on tty hangup in process context.
- *
- * Wait for I/O to driver to complete and unregister PPP channel.
- * This is already done by the close routine, so just call that.
- */
-static int ppp_asynctty_hangup(struct tty_struct *tty)
-{
- ppp_asynctty_close(tty);
- return 0;
-}
-
-/*
- * Read does nothing - no data is ever available this way.
- * Pppd reads and writes packets via /dev/ppp instead.
- */
-static ssize_t
-ppp_asynctty_read(struct tty_struct *tty, struct file *file,
- unsigned char __user *buf, size_t count)
-{
- return -EAGAIN;
-}
-
-/*
- * Write on the tty does nothing, the packets all come in
- * from the ppp generic stuff.
- */
-static ssize_t
-ppp_asynctty_write(struct tty_struct *tty, struct file *file,
- const unsigned char *buf, size_t count)
-{
- return -EAGAIN;
-}
-
-/*
- * Called in process context only. May be re-entered by multiple
- * ioctl calling threads.
- */
-
-static int
-ppp_asynctty_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- struct asyncppp *ap = ap_get(tty);
- int err, val;
- int __user *p = (int __user *)arg;
-
- if (!ap)
- return -ENXIO;
- err = -EFAULT;
- switch (cmd) {
- case PPPIOCGCHAN:
- err = -EFAULT;
- if (put_user(ppp_channel_index(&ap->chan), p))
- break;
- err = 0;
- break;
-
- case PPPIOCGUNIT:
- err = -EFAULT;
- if (put_user(ppp_unit_number(&ap->chan), p))
- break;
- err = 0;
- break;
-
- case TCFLSH:
- /* flush our buffers and the serial port's buffer */
- if (arg == TCIOFLUSH || arg == TCOFLUSH)
- ppp_async_flush_output(ap);
- err = tty_perform_flush(tty, arg);
- break;
-
- case FIONREAD:
- val = 0;
- if (put_user(val, p))
- break;
- err = 0;
- break;
-
- default:
- /* Try the various mode ioctls */
- err = tty_mode_ioctl(tty, file, cmd, arg);
- }
-
- ap_put(ap);
- return err;
-}
-
-/* No kernel lock - fine */
-static unsigned int
-ppp_asynctty_poll(struct tty_struct *tty, struct file *file, poll_table *wait)
-{
- return 0;
-}
-
-/* May sleep, don't call from interrupt level or with interrupts disabled */
-static void
-ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf,
- char *cflags, int count)
-{
- struct asyncppp *ap = ap_get(tty);
- unsigned long flags;
-
- if (!ap)
- return;
- spin_lock_irqsave(&ap->recv_lock, flags);
- ppp_async_input(ap, buf, cflags, count);
- spin_unlock_irqrestore(&ap->recv_lock, flags);
- if (!skb_queue_empty(&ap->rqueue))
- tasklet_schedule(&ap->tsk);
- ap_put(ap);
- tty_unthrottle(tty);
-}
-
-static void
-ppp_asynctty_wakeup(struct tty_struct *tty)
-{
- struct asyncppp *ap = ap_get(tty);
-
- clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- if (!ap)
- return;
- set_bit(XMIT_WAKEUP, &ap->xmit_flags);
- tasklet_schedule(&ap->tsk);
- ap_put(ap);
-}
-
-
-static struct tty_ldisc_ops ppp_ldisc = {
- .owner = THIS_MODULE,
- .magic = TTY_LDISC_MAGIC,
- .name = "ppp",
- .open = ppp_asynctty_open,
- .close = ppp_asynctty_close,
- .hangup = ppp_asynctty_hangup,
- .read = ppp_asynctty_read,
- .write = ppp_asynctty_write,
- .ioctl = ppp_asynctty_ioctl,
- .poll = ppp_asynctty_poll,
- .receive_buf = ppp_asynctty_receive,
- .write_wakeup = ppp_asynctty_wakeup,
-};
-
-static int __init
-ppp_async_init(void)
-{
- int err;
-
- err = tty_register_ldisc(N_PPP, &ppp_ldisc);
- if (err != 0)
- printk(KERN_ERR "PPP_async: error %d registering line disc.\n",
- err);
- return err;
-}
-
-/*
- * The following routines provide the PPP channel interface.
- */
-static int
-ppp_async_ioctl(struct ppp_channel *chan, unsigned int cmd, unsigned long arg)
-{
- struct asyncppp *ap = chan->private;
- void __user *argp = (void __user *)arg;
- int __user *p = argp;
- int err, val;
- u32 accm[8];
-
- err = -EFAULT;
- switch (cmd) {
- case PPPIOCGFLAGS:
- val = ap->flags | ap->rbits;
- if (put_user(val, p))
- break;
- err = 0;
- break;
- case PPPIOCSFLAGS:
- if (get_user(val, p))
- break;
- ap->flags = val & ~SC_RCV_BITS;
- spin_lock_irq(&ap->recv_lock);
- ap->rbits = val & SC_RCV_BITS;
- spin_unlock_irq(&ap->recv_lock);
- err = 0;
- break;
-
- case PPPIOCGASYNCMAP:
- if (put_user(ap->xaccm[0], (u32 __user *)argp))
- break;
- err = 0;
- break;
- case PPPIOCSASYNCMAP:
- if (get_user(ap->xaccm[0], (u32 __user *)argp))
- break;
- err = 0;
- break;
-
- case PPPIOCGRASYNCMAP:
- if (put_user(ap->raccm, (u32 __user *)argp))
- break;
- err = 0;
- break;
- case PPPIOCSRASYNCMAP:
- if (get_user(ap->raccm, (u32 __user *)argp))
- break;
- err = 0;
- break;
-
- case PPPIOCGXASYNCMAP:
- if (copy_to_user(argp, ap->xaccm, sizeof(ap->xaccm)))
- break;
- err = 0;
- break;
- case PPPIOCSXASYNCMAP:
- if (copy_from_user(accm, argp, sizeof(accm)))
- break;
- accm[2] &= ~0x40000000U; /* can't escape 0x5e */
- accm[3] |= 0x60000000U; /* must escape 0x7d, 0x7e */
- memcpy(ap->xaccm, accm, sizeof(ap->xaccm));
- err = 0;
- break;
-
- case PPPIOCGMRU:
- if (put_user(ap->mru, p))
- break;
- err = 0;
- break;
- case PPPIOCSMRU:
- if (get_user(val, p))
- break;
- if (val < PPP_MRU)
- val = PPP_MRU;
- ap->mru = val;
- err = 0;
- break;
-
- default:
- err = -ENOTTY;
- }
-
- return err;
-}
-
-/*
- * This is called at softirq level to deliver received packets
- * to the ppp_generic code, and to tell the ppp_generic code
- * if we can accept more output now.
- */
-static void ppp_async_process(unsigned long arg)
-{
- struct asyncppp *ap = (struct asyncppp *) arg;
- struct sk_buff *skb;
-
- /* process received packets */
- while ((skb = skb_dequeue(&ap->rqueue)) != NULL) {
- if (skb->cb[0])
- ppp_input_error(&ap->chan, 0);
- ppp_input(&ap->chan, skb);
- }
-
- /* try to push more stuff out */
- if (test_bit(XMIT_WAKEUP, &ap->xmit_flags) && ppp_async_push(ap))
- ppp_output_wakeup(&ap->chan);
-}
-
-/*
- * Procedures for encapsulation and framing.
- */
-
-/*
- * Procedure to encode the data for async serial transmission.
- * Does octet stuffing (escaping), puts the address/control bytes
- * on if A/C compression is disabled, and does protocol compression.
- * Assumes ap->tpkt != 0 on entry.
- * Returns 1 if we finished the current frame, 0 otherwise.
- */
-
-#define PUT_BYTE(ap, buf, c, islcp) do { \
- if ((islcp && c < 0x20) || (ap->xaccm[c >> 5] & (1 << (c & 0x1f)))) {\
- *buf++ = PPP_ESCAPE; \
- *buf++ = c ^ PPP_TRANS; \
- } else \
- *buf++ = c; \
-} while (0)
-
-static int
-ppp_async_encode(struct asyncppp *ap)
-{
- int fcs, i, count, c, proto;
- unsigned char *buf, *buflim;
- unsigned char *data;
- int islcp;
-
- buf = ap->obuf;
- ap->olim = buf;
- ap->optr = buf;
- i = ap->tpkt_pos;
- data = ap->tpkt->data;
- count = ap->tpkt->len;
- fcs = ap->tfcs;
- proto = get_unaligned_be16(data);
-
- /*
- * LCP packets with code values between 1 (configure-reqest)
- * and 7 (code-reject) must be sent as though no options
- * had been negotiated.
- */
- islcp = proto == PPP_LCP && 1 <= data[2] && data[2] <= 7;
-
- if (i == 0) {
- if (islcp)
- async_lcp_peek(ap, data, count, 0);
-
- /*
- * Start of a new packet - insert the leading FLAG
- * character if necessary.
- */
- if (islcp || flag_time == 0 ||
- time_after_eq(jiffies, ap->last_xmit + flag_time))
- *buf++ = PPP_FLAG;
- ap->last_xmit = jiffies;
- fcs = PPP_INITFCS;
-
- /*
- * Put in the address/control bytes if necessary
- */
- if ((ap->flags & SC_COMP_AC) == 0 || islcp) {
- PUT_BYTE(ap, buf, 0xff, islcp);
- fcs = PPP_FCS(fcs, 0xff);
- PUT_BYTE(ap, buf, 0x03, islcp);
- fcs = PPP_FCS(fcs, 0x03);
- }
- }
-
- /*
- * Once we put in the last byte, we need to put in the FCS
- * and closing flag, so make sure there is at least 7 bytes
- * of free space in the output buffer.
- */
- buflim = ap->obuf + OBUFSIZE - 6;
- while (i < count && buf < buflim) {
- c = data[i++];
- if (i == 1 && c == 0 && (ap->flags & SC_COMP_PROT))
- continue; /* compress protocol field */
- fcs = PPP_FCS(fcs, c);
- PUT_BYTE(ap, buf, c, islcp);
- }
-
- if (i < count) {
- /*
- * Remember where we are up to in this packet.
- */
- ap->olim = buf;
- ap->tpkt_pos = i;
- ap->tfcs = fcs;
- return 0;
- }
-
- /*
- * We have finished the packet. Add the FCS and flag.
- */
- fcs = ~fcs;
- c = fcs & 0xff;
- PUT_BYTE(ap, buf, c, islcp);
- c = (fcs >> 8) & 0xff;
- PUT_BYTE(ap, buf, c, islcp);
- *buf++ = PPP_FLAG;
- ap->olim = buf;
-
- kfree_skb(ap->tpkt);
- ap->tpkt = NULL;
- return 1;
-}
-
-/*
- * Transmit-side routines.
- */
-
-/*
- * Send a packet to the peer over an async tty line.
- * Returns 1 iff the packet was accepted.
- * If the packet was not accepted, we will call ppp_output_wakeup
- * at some later time.
- */
-static int
-ppp_async_send(struct ppp_channel *chan, struct sk_buff *skb)
-{
- struct asyncppp *ap = chan->private;
-
- ppp_async_push(ap);
-
- if (test_and_set_bit(XMIT_FULL, &ap->xmit_flags))
- return 0; /* already full */
- ap->tpkt = skb;
- ap->tpkt_pos = 0;
-
- ppp_async_push(ap);
- return 1;
-}
-
-/*
- * Push as much data as possible out to the tty.
- */
-static int
-ppp_async_push(struct asyncppp *ap)
-{
- int avail, sent, done = 0;
- struct tty_struct *tty = ap->tty;
- int tty_stuffed = 0;
-
- /*
- * We can get called recursively here if the tty write
- * function calls our wakeup function. This can happen
- * for example on a pty with both the master and slave
- * set to PPP line discipline.
- * We use the XMIT_BUSY bit to detect this and get out,
- * leaving the XMIT_WAKEUP bit set to tell the other
- * instance that it may now be able to write more now.
- */
- if (test_and_set_bit(XMIT_BUSY, &ap->xmit_flags))
- return 0;
- spin_lock_bh(&ap->xmit_lock);
- for (;;) {
- if (test_and_clear_bit(XMIT_WAKEUP, &ap->xmit_flags))
- tty_stuffed = 0;
- if (!tty_stuffed && ap->optr < ap->olim) {
- avail = ap->olim - ap->optr;
- set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- sent = tty->ops->write(tty, ap->optr, avail);
- if (sent < 0)
- goto flush; /* error, e.g. loss of CD */
- ap->optr += sent;
- if (sent < avail)
- tty_stuffed = 1;
- continue;
- }
- if (ap->optr >= ap->olim && ap->tpkt) {
- if (ppp_async_encode(ap)) {
- /* finished processing ap->tpkt */
- clear_bit(XMIT_FULL, &ap->xmit_flags);
- done = 1;
- }
- continue;
- }
- /*
- * We haven't made any progress this time around.
- * Clear XMIT_BUSY to let other callers in, but
- * after doing so we have to check if anyone set
- * XMIT_WAKEUP since we last checked it. If they
- * did, we should try again to set XMIT_BUSY and go
- * around again in case XMIT_BUSY was still set when
- * the other caller tried.
- */
- clear_bit(XMIT_BUSY, &ap->xmit_flags);
- /* any more work to do? if not, exit the loop */
- if (!(test_bit(XMIT_WAKEUP, &ap->xmit_flags) ||
- (!tty_stuffed && ap->tpkt)))
- break;
- /* more work to do, see if we can do it now */
- if (test_and_set_bit(XMIT_BUSY, &ap->xmit_flags))
- break;
- }
- spin_unlock_bh(&ap->xmit_lock);
- return done;
-
-flush:
- clear_bit(XMIT_BUSY, &ap->xmit_flags);
- if (ap->tpkt) {
- kfree_skb(ap->tpkt);
- ap->tpkt = NULL;
- clear_bit(XMIT_FULL, &ap->xmit_flags);
- done = 1;
- }
- ap->optr = ap->olim;
- spin_unlock_bh(&ap->xmit_lock);
- return done;
-}
-
-/*
- * Flush output from our internal buffers.
- * Called for the TCFLSH ioctl. Can be entered in parallel
- * but this is covered by the xmit_lock.
- */
-static void
-ppp_async_flush_output(struct asyncppp *ap)
-{
- int done = 0;
-
- spin_lock_bh(&ap->xmit_lock);
- ap->optr = ap->olim;
- if (ap->tpkt != NULL) {
- kfree_skb(ap->tpkt);
- ap->tpkt = NULL;
- clear_bit(XMIT_FULL, &ap->xmit_flags);
- done = 1;
- }
- spin_unlock_bh(&ap->xmit_lock);
- if (done)
- ppp_output_wakeup(&ap->chan);
-}
-
-/*
- * Receive-side routines.
- */
-
-/* see how many ordinary chars there are at the start of buf */
-static inline int
-scan_ordinary(struct asyncppp *ap, const unsigned char *buf, int count)
-{
- int i, c;
-
- for (i = 0; i < count; ++i) {
- c = buf[i];
- if (c == PPP_ESCAPE || c == PPP_FLAG ||
- (c < 0x20 && (ap->raccm & (1 << c)) != 0))
- break;
- }
- return i;
-}
-
-/* called when a flag is seen - do end-of-packet processing */
-static void
-process_input_packet(struct asyncppp *ap)
-{
- struct sk_buff *skb;
- unsigned char *p;
- unsigned int len, fcs, proto;
-
- skb = ap->rpkt;
- if (ap->state & (SC_TOSS | SC_ESCAPE))
- goto err;
-
- if (skb == NULL)
- return; /* 0-length packet */
-
- /* check the FCS */
- p = skb->data;
- len = skb->len;
- if (len < 3)
- goto err; /* too short */
- fcs = PPP_INITFCS;
- for (; len > 0; --len)
- fcs = PPP_FCS(fcs, *p++);
- if (fcs != PPP_GOODFCS)
- goto err; /* bad FCS */
- skb_trim(skb, skb->len - 2);
-
- /* check for address/control and protocol compression */
- p = skb->data;
- if (p[0] == PPP_ALLSTATIONS) {
- /* chop off address/control */
- if (p[1] != PPP_UI || skb->len < 3)
- goto err;
- p = skb_pull(skb, 2);
- }
- proto = p[0];
- if (proto & 1) {
- /* protocol is compressed */
- skb_push(skb, 1)[0] = 0;
- } else {
- if (skb->len < 2)
- goto err;
- proto = (proto << 8) + p[1];
- if (proto == PPP_LCP)
- async_lcp_peek(ap, p, skb->len, 1);
- }
-
- /* queue the frame to be processed */
- skb->cb[0] = ap->state;
- skb_queue_tail(&ap->rqueue, skb);
- ap->rpkt = NULL;
- ap->state = 0;
- return;
-
- err:
- /* frame had an error, remember that, reset SC_TOSS & SC_ESCAPE */
- ap->state = SC_PREV_ERROR;
- if (skb) {
- /* make skb appear as freshly allocated */
- skb_trim(skb, 0);
- skb_reserve(skb, - skb_headroom(skb));
- }
-}
-
-/* Called when the tty driver has data for us. Runs parallel with the
- other ldisc functions but will not be re-entered */
-
-static void
-ppp_async_input(struct asyncppp *ap, const unsigned char *buf,
- char *flags, int count)
-{
- struct sk_buff *skb;
- int c, i, j, n, s, f;
- unsigned char *sp;
-
- /* update bits used for 8-bit cleanness detection */
- if (~ap->rbits & SC_RCV_BITS) {
- s = 0;
- for (i = 0; i < count; ++i) {
- c = buf[i];
- if (flags && flags[i] != 0)
- continue;
- s |= (c & 0x80)? SC_RCV_B7_1: SC_RCV_B7_0;
- c = ((c >> 4) ^ c) & 0xf;
- s |= (0x6996 & (1 << c))? SC_RCV_ODDP: SC_RCV_EVNP;
- }
- ap->rbits |= s;
- }
-
- while (count > 0) {
- /* scan through and see how many chars we can do in bulk */
- if ((ap->state & SC_ESCAPE) && buf[0] == PPP_ESCAPE)
- n = 1;
- else
- n = scan_ordinary(ap, buf, count);
-
- f = 0;
- if (flags && (ap->state & SC_TOSS) == 0) {
- /* check the flags to see if any char had an error */
- for (j = 0; j < n; ++j)
- if ((f = flags[j]) != 0)
- break;
- }
- if (f != 0) {
- /* start tossing */
- ap->state |= SC_TOSS;
-
- } else if (n > 0 && (ap->state & SC_TOSS) == 0) {
- /* stuff the chars in the skb */
- skb = ap->rpkt;
- if (!skb) {
- skb = dev_alloc_skb(ap->mru + PPP_HDRLEN + 2);
- if (!skb)
- goto nomem;
- ap->rpkt = skb;
- }
- if (skb->len == 0) {
- /* Try to get the payload 4-byte aligned.
- * This should match the
- * PPP_ALLSTATIONS/PPP_UI/compressed tests in
- * process_input_packet, but we do not have
- * enough chars here to test buf[1] and buf[2].
- */
- if (buf[0] != PPP_ALLSTATIONS)
- skb_reserve(skb, 2 + (buf[0] & 1));
- }
- if (n > skb_tailroom(skb)) {
- /* packet overflowed MRU */
- ap->state |= SC_TOSS;
- } else {
- sp = skb_put(skb, n);
- memcpy(sp, buf, n);
- if (ap->state & SC_ESCAPE) {
- sp[0] ^= PPP_TRANS;
- ap->state &= ~SC_ESCAPE;
- }
- }
- }
-
- if (n >= count)
- break;
-
- c = buf[n];
- if (flags != NULL && flags[n] != 0) {
- ap->state |= SC_TOSS;
- } else if (c == PPP_FLAG) {
- process_input_packet(ap);
- } else if (c == PPP_ESCAPE) {
- ap->state |= SC_ESCAPE;
- } else if (I_IXON(ap->tty)) {
- if (c == START_CHAR(ap->tty))
- start_tty(ap->tty);
- else if (c == STOP_CHAR(ap->tty))
- stop_tty(ap->tty);
- }
- /* otherwise it's a char in the recv ACCM */
- ++n;
-
- buf += n;
- if (flags)
- flags += n;
- count -= n;
- }
- return;
-
- nomem:
- printk(KERN_ERR "PPPasync: no memory (input pkt)\n");
- ap->state |= SC_TOSS;
-}
-
-/*
- * We look at LCP frames going past so that we can notice
- * and react to the LCP configure-ack from the peer.
- * In the situation where the peer has been sent a configure-ack
- * already, LCP is up once it has sent its configure-ack
- * so the immediately following packet can be sent with the
- * configured LCP options. This allows us to process the following
- * packet correctly without pppd needing to respond quickly.
- *
- * We only respond to the received configure-ack if we have just
- * sent a configure-request, and the configure-ack contains the
- * same data (this is checked using a 16-bit crc of the data).
- */
-#define CONFREQ 1 /* LCP code field values */
-#define CONFACK 2
-#define LCP_MRU 1 /* LCP option numbers */
-#define LCP_ASYNCMAP 2
-
-static void async_lcp_peek(struct asyncppp *ap, unsigned char *data,
- int len, int inbound)
-{
- int dlen, fcs, i, code;
- u32 val;
-
- data += 2; /* skip protocol bytes */
- len -= 2;
- if (len < 4) /* 4 = code, ID, length */
- return;
- code = data[0];
- if (code != CONFACK && code != CONFREQ)
- return;
- dlen = get_unaligned_be16(data + 2);
- if (len < dlen)
- return; /* packet got truncated or length is bogus */
-
- if (code == (inbound? CONFACK: CONFREQ)) {
- /*
- * sent confreq or received confack:
- * calculate the crc of the data from the ID field on.
- */
- fcs = PPP_INITFCS;
- for (i = 1; i < dlen; ++i)
- fcs = PPP_FCS(fcs, data[i]);
-
- if (!inbound) {
- /* outbound confreq - remember the crc for later */
- ap->lcp_fcs = fcs;
- return;
- }
-
- /* received confack, check the crc */
- fcs ^= ap->lcp_fcs;
- ap->lcp_fcs = -1;
- if (fcs != 0)
- return;
- } else if (inbound)
- return; /* not interested in received confreq */
-
- /* process the options in the confack */
- data += 4;
- dlen -= 4;
- /* data[0] is code, data[1] is length */
- while (dlen >= 2 && dlen >= data[1] && data[1] >= 2) {
- switch (data[0]) {
- case LCP_MRU:
- val = get_unaligned_be16(data + 2);
- if (inbound)
- ap->mru = val;
- else
- ap->chan.mtu = val;
- break;
- case LCP_ASYNCMAP:
- val = get_unaligned_be32(data + 2);
- if (inbound)
- ap->raccm = val;
- else
- ap->xaccm[0] = val;
- break;
- }
- dlen -= data[1];
- data += data[1];
- }
-}
-
-static void __exit ppp_async_cleanup(void)
-{
- if (tty_unregister_ldisc(N_PPP) != 0)
- printk(KERN_ERR "failed to unregister PPP line discipline\n");
-}
-
-module_init(ppp_async_init);
-module_exit(ppp_async_cleanup);