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Commit 43cbb0e0 authored by Ralf Bächle's avatar Ralf Bächle
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[PATCH] Another big 6pack patch 

Below another 6pack patch which I've got sitting in my repository for a
while already.  The patch does:

 o Update my callsign
 o Cleanup the internal for synchronization with a 6pack TNC a little bit
   so it won't result in heaps and piles of messages in syslogs as it used
   to do.
 o Does paranoia checks for the maximum allowable packet size on transmit.
   There was a slight chance this might have resulted in a crash in just
   the right configuration.
 o Verifies the address family for the SIOCSIFHWADDR network interface
   ioctl.
 o Tries to do proper locking so nothing will access dev->dev_addr in
   midflight while changing the layer 2 address.
 o Uses an intermediate buffer for the SIOCSIFHWADDR ioctl so an error in
   copy_from_user can't result in a half-modified MAC address.
 o Swaps the arguments of decode_prio_command, decode_std_command and
   decode_data such that for consistency the struct sixpack pointer will be
   the first argument like everywhere else.
Signed-off-by: default avatarJeff Garzik <jgarzik@pobox.com>
parent 1b6aa634
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Showing with 179 additions and 191 deletions
drivers/net/hamradio/6pack.c
View file @ 43cbb0e0
......@@ -4,7 +4,7 @@
* kernel's AX.25 protocol layers.
*
* Authors: Andreas Knsgen <ajk@iehk.rwth-aachen.de>
* Ralf Baechle DO1GRB <ralf@linux-mips.org>
* Ralf Baechle DL5RB <ralf@linux-mips.org>
*
* Quite a lot of stuff "stolen" by Joerg Reuter from slip.c, written by
*
......@@ -119,11 +119,10 @@ struct sixpack {
unsigned char status1;
unsigned char status2;
unsigned char tx_enable;
unsigned char tnc_ok;
unsigned char tnc_state;
struct timer_list tx_t;
struct timer_list resync_t;
atomic_t refcnt;
struct semaphore dead_sem;
spinlock_t lock;
......@@ -134,7 +133,6 @@ struct sixpack {
static void sp_start_tx_timer(struct sixpack *);
static void sixpack_decode(struct sixpack *, unsigned char[], int);
static int encode_sixpack(unsigned char *, unsigned char *, int, unsigned char);
static int sixpack_init(struct net_device *dev);
/*
* perform the persistence/slottime algorithm for CSMA access. If the
......@@ -187,6 +185,11 @@ static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len)
goto out_drop;
}
if (len > sp->mtu) { /* sp->mtu = AX25_MTU = max. PACLEN = 256 */
msg = "oversized transmit packet!";
goto out_drop;
}
if (p[0] > 5) {
msg = "invalid KISS command";
goto out_drop;
......@@ -249,8 +252,8 @@ static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len)
out_drop:
sp->stats.tx_dropped++;
netif_start_queue(sp->dev);
printk(KERN_DEBUG "%s: %s - dropped.\n", sp->dev->name, msg);
return;
if (net_ratelimit())
printk(KERN_DEBUG "%s: %s - dropped.\n", sp->dev->name, msg);
}
/* Encapsulate an IP datagram and kick it into a TTY queue. */
......@@ -313,10 +316,20 @@ static struct net_device_stats *sp_get_stats(struct net_device *dev)
return &sp->stats;
}
static int sp_set_dev_mac_address(struct net_device *dev, void *addr)
static int sp_set_mac_address(struct net_device *dev, void *addr)
{
struct sockaddr *sa = addr;
memcpy(dev->dev_addr, sa->sa_data, AX25_ADDR_LEN);
struct sockaddr_ax25 *sa = addr;
if (sa->sax25_family != AF_AX25)
return -EINVAL;
if (!sa->sax25_ndigis)
return -EINVAL;
spin_lock_irq(&dev->xmit_lock);
memcpy(dev->dev_addr, &sa->sax25_call, AX25_ADDR_LEN);
spin_unlock_irq(&dev->xmit_lock);
return 0;
}
......@@ -337,7 +350,6 @@ static void sp_setup(struct net_device *dev)
{'L'<<1,'I'<<1,'N'<<1,'U'<<1,'X'<<1,' '<<1,'1'<<1};
/* Finish setting up the DEVICE info. */
dev->init = sixpack_init;
dev->mtu = SIXP_MTU;
dev->hard_start_xmit = sp_xmit;
dev->open = sp_open_dev;
......@@ -345,7 +357,7 @@ static void sp_setup(struct net_device *dev)
dev->stop = sp_close;
dev->hard_header = sp_header;
dev->get_stats = sp_get_stats;
dev->set_mac_address = sp_set_dev_mac_address;
dev->set_mac_address = sp_set_mac_address;
dev->hard_header_len = AX25_MAX_HEADER_LEN;
dev->addr_len = AX25_ADDR_LEN;
dev->type = ARPHRD_AX25;
......@@ -359,51 +371,9 @@ static void sp_setup(struct net_device *dev)
SET_MODULE_OWNER(dev);
/* New-style flags. */
dev->flags = 0;
}
/* Find a free 6pack channel, and link in this `tty' line. */
static inline struct sixpack *sp_alloc(void)
{
struct sixpack *sp = NULL;
struct net_device *dev = NULL;
dev = alloc_netdev(sizeof(struct sixpack), "sp%d", sp_setup);
if (!dev)
return NULL;
sp = netdev_priv(dev);
sp->dev = dev;
spin_lock_init(&sp->lock);
if (register_netdev(dev))
goto out_free;
return sp;
out_free:
printk(KERN_WARNING "sp_alloc() - register_netdev() failure.\n");
free_netdev(dev);
return NULL;
}
/* Free a 6pack channel. */
static inline void sp_free(struct sixpack *sp)
{
void * tmp;
/* Free all 6pack frame buffers. */
if ((tmp = xchg(&sp->rbuff, NULL)) != NULL)
kfree(tmp);
if ((tmp = xchg(&sp->xbuff, NULL)) != NULL)
kfree(tmp);
}
/* Send one completely decapsulated IP datagram to the IP layer. */
/*
......@@ -482,6 +452,8 @@ static void sixpack_write_wakeup(struct tty_struct *tty)
struct sixpack *sp = sp_get(tty);
int actual;
if (!sp)
return;
if (sp->xleft <= 0) {
/* Now serial buffer is almost free & we can start
* transmission of another packet */
......@@ -492,7 +464,7 @@ static void sixpack_write_wakeup(struct tty_struct *tty)
goto out;
}
if (sp->tx_enable == 1) {
if (sp->tx_enable) {
actual = tty->driver->write(tty, sp->xhead, sp->xleft);
sp->xleft -= actual;
sp->xhead += actual;
......@@ -504,80 +476,6 @@ static void sixpack_write_wakeup(struct tty_struct *tty)
/* ----------------------------------------------------------------------- */
/* Open the low-level part of the 6pack channel. */
static int sp_open(struct net_device *dev)
{
struct sixpack *sp = netdev_priv(dev);
char *rbuff, *xbuff = NULL;
int err = -ENOBUFS;
unsigned long len;
/* !!! length of the buffers. MTU is IP MTU, not PACLEN! */
len = dev->mtu * 2;
rbuff = kmalloc(len + 4, GFP_KERNEL);
if (rbuff == NULL)
goto err_exit;
xbuff = kmalloc(len + 4, GFP_KERNEL);
if (xbuff == NULL)
goto err_exit;
spin_lock_bh(&sp->lock);
if (sp->tty == NULL)
return -ENODEV;
/*
* Allocate the 6pack frame buffers:
*
* rbuff Receive buffer.
* xbuff Transmit buffer.
*/
rbuff = xchg(&sp->rbuff, rbuff);
xbuff = xchg(&sp->xbuff, xbuff);
sp->mtu = AX25_MTU + 73;
sp->buffsize = len;
sp->rcount = 0;
sp->rx_count = 0;
sp->rx_count_cooked = 0;
sp->xleft = 0;
sp->flags = 0; /* Clear ESCAPE & ERROR flags */
sp->duplex = 0;
sp->tx_delay = SIXP_TXDELAY;
sp->persistence = SIXP_PERSIST;
sp->slottime = SIXP_SLOTTIME;
sp->led_state = 0x60;
sp->status = 1;
sp->status1 = 1;
sp->status2 = 0;
sp->tnc_ok = 0;
sp->tx_enable = 0;
netif_start_queue(dev);
init_timer(&sp->tx_t);
init_timer(&sp->resync_t);
spin_unlock_bh(&sp->lock);
err = 0;
err_exit:
if (xbuff)
kfree(xbuff);
if (rbuff)
kfree(rbuff);
return err;
}
static int sixpack_receive_room(struct tty_struct *tty)
{
return 65536; /* We can handle an infinite amount of data. :-) */
......@@ -629,14 +527,45 @@ static void sixpack_receive_buf(struct tty_struct *tty,
* decode_prio_command
*/
#define TNC_UNINITIALIZED 0
#define TNC_UNSYNC_STARTUP 1
#define TNC_UNSYNCED 2
#define TNC_IN_SYNC 3
static void __tnc_set_sync_state(struct sixpack *sp, int new_tnc_state)
{
char *msg;
switch (new_tnc_state) {
default: /* gcc oh piece-o-crap ... */
case TNC_UNSYNC_STARTUP:
msg = "Synchronizing with TNC";
break;
case TNC_UNSYNCED:
msg = "Lost synchronization with TNC\n";
break;
case TNC_IN_SYNC:
msg = "Found TNC";
break;
}
sp->tnc_state = new_tnc_state;
printk(KERN_INFO "%s: %s\n", sp->dev->name, msg);
}
static inline void tnc_set_sync_state(struct sixpack *sp, int new_tnc_state)
{
int old_tnc_state = sp->tnc_state;
if (old_tnc_state != new_tnc_state)
__tnc_set_sync_state(sp, new_tnc_state);
}
static void resync_tnc(unsigned long channel)
{
struct sixpack *sp = (struct sixpack *) channel;
struct net_device *dev = sp->dev;
static char resync_cmd = 0xe8;
printk(KERN_INFO "%s: resyncing TNC\n", dev->name);
/* clear any data that might have been received */
sp->rx_count = 0;
......@@ -647,7 +576,6 @@ static void resync_tnc(unsigned long channel)
sp->status = 1;
sp->status1 = 1;
sp->status2 = 0;
sp->tnc_ok = 0;
/* resync the TNC */
......@@ -659,9 +587,9 @@ static void resync_tnc(unsigned long channel)
/* Start resync timer again -- the TNC might be still absent */
del_timer(&sp->resync_t);
sp->resync_t.data = (unsigned long) sp;
sp->resync_t.function = resync_tnc;
sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT;
sp->resync_t.data = (unsigned long) sp;
sp->resync_t.function = resync_tnc;
sp->resync_t.expires = jiffies + SIXP_RESYNC_TIMEOUT;
add_timer(&sp->resync_t);
}
......@@ -669,6 +597,8 @@ static inline int tnc_init(struct sixpack *sp)
{
unsigned char inbyte = 0xe8;
tnc_set_sync_state(sp, TNC_UNSYNC_STARTUP);
sp->tty->driver->write(sp->tty, &inbyte, 1);
del_timer(&sp->resync_t);
......@@ -689,31 +619,91 @@ static inline int tnc_init(struct sixpack *sp)
*/
static int sixpack_open(struct tty_struct *tty)
{
char *rbuff = NULL, *xbuff = NULL;
struct net_device *dev;
struct sixpack *sp;
unsigned long len;
int err = 0;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
sp = sp_alloc();
if (!sp) {
dev = alloc_netdev(sizeof(struct sixpack), "sp%d", sp_setup);
if (!dev) {
err = -ENOMEM;
goto out;
}
sp->tty = tty;
sp = netdev_priv(dev);
sp->dev = dev;
spin_lock_init(&sp->lock);
atomic_set(&sp->refcnt, 1);
init_MUTEX_LOCKED(&sp->dead_sem);
/* Perform the low-level 6pack initialization. */
if ((err = sp_open(sp->dev)))
goto out;
/* !!! length of the buffers. MTU is IP MTU, not PACLEN! */
len = dev->mtu * 2;
rbuff = kmalloc(len + 4, GFP_KERNEL);
xbuff = kmalloc(len + 4, GFP_KERNEL);
if (rbuff == NULL || xbuff == NULL) {
err = -ENOBUFS;
goto out_free;
}
spin_lock_bh(&sp->lock);
sp->tty = tty;
sp->rbuff = rbuff;
sp->xbuff = xbuff;
sp->mtu = AX25_MTU + 73;
sp->buffsize = len;
sp->rcount = 0;
sp->rx_count = 0;
sp->rx_count_cooked = 0;
sp->xleft = 0;
sp->flags = 0; /* Clear ESCAPE & ERROR flags */
sp->duplex = 0;
sp->tx_delay = SIXP_TXDELAY;
sp->persistence = SIXP_PERSIST;
sp->slottime = SIXP_SLOTTIME;
sp->led_state = 0x60;
sp->status = 1;
sp->status1 = 1;
sp->status2 = 0;
sp->tx_enable = 0;
netif_start_queue(dev);
init_timer(&sp->tx_t);
init_timer(&sp->resync_t);
spin_unlock_bh(&sp->lock);
/* Done. We have linked the TTY line to a channel. */
tty->disc_data = sp;
/* Now we're ready to register. */
if (register_netdev(dev))
goto out_free;
tnc_init(sp);
return 0;
out_free:
kfree(xbuff);
kfree(rbuff);
if (dev)
free_netdev(dev);
out:
return err;
}
......@@ -727,7 +717,7 @@ static int sixpack_open(struct tty_struct *tty)
*/
static void sixpack_close(struct tty_struct *tty)
{
struct sixpack *sp = (struct sixpack *) tty->disc_data;
struct sixpack *sp;
write_lock(&disc_data_lock);
sp = tty->disc_data;
......@@ -743,16 +733,14 @@ static void sixpack_close(struct tty_struct *tty)
if (!atomic_dec_and_test(&sp->refcnt))
down(&sp->dead_sem);
unregister_netdev(sp->dev);
del_timer(&sp->tx_t);
del_timer(&sp->resync_t);
sp_free(sp);
unregister_netdev(sp->dev);
}
static int sp_set_mac_address(struct net_device *dev, void __user *addr)
{
return copy_from_user(dev->dev_addr, addr, AX25_ADDR_LEN) ? -EFAULT : 0;
/* Free all 6pack frame buffers. */
kfree(sp->rbuff);
kfree(sp->xbuff);
}
/* Perform I/O control on an active 6pack channel. */
......@@ -760,6 +748,7 @@ static int sixpack_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct sixpack *sp = sp_get(tty);
struct net_device *dev = sp->dev;
unsigned int tmp, err;
if (!sp)
......@@ -767,8 +756,8 @@ static int sixpack_ioctl(struct tty_struct *tty, struct file *file,
switch(cmd) {
case SIOCGIFNAME:
err = copy_to_user((void __user *) arg, sp->dev->name,
strlen(sp->dev->name) + 1) ? -EFAULT : 0;
err = copy_to_user((void *) arg, dev->name,
strlen(dev->name) + 1) ? -EFAULT : 0;
break;
case SIOCGIFENCAP:
......@@ -782,16 +771,30 @@ static int sixpack_ioctl(struct tty_struct *tty, struct file *file,
}
sp->mode = tmp;
sp->dev->addr_len = AX25_ADDR_LEN; /* sizeof an AX.25 addr */
sp->dev->hard_header_len = AX25_KISS_HEADER_LEN + AX25_MAX_HEADER_LEN + 3;
sp->dev->type = ARPHRD_AX25;
dev->addr_len = AX25_ADDR_LEN;
dev->hard_header_len = AX25_KISS_HEADER_LEN +
AX25_MAX_HEADER_LEN + 3;
dev->type = ARPHRD_AX25;
err = 0;
break;
case SIOCSIFHWADDR:
err = sp_set_mac_address(sp->dev, (void __user *) arg);
case SIOCSIFHWADDR: {
char addr[AX25_ADDR_LEN];
if (copy_from_user(&addr,
(void __user *) arg, AX25_ADDR_LEN)) {
err = -EFAULT;
break;
}
spin_lock_irq(&dev->xmit_lock);
memcpy(dev->dev_addr, &addr, AX25_ADDR_LEN);
spin_unlock_irq(&dev->xmit_lock);
err = 0;
break;
}
/* Allow stty to read, but not set, the serial port */
case TCGETS:
......@@ -800,7 +803,7 @@ static int sixpack_ioctl(struct tty_struct *tty, struct file *file,
break;
default:
return -ENOIOCTLCMD;
err = -ENOIOCTLCMD;
}
sp_put(sp);
......@@ -808,7 +811,6 @@ static int sixpack_ioctl(struct tty_struct *tty, struct file *file,
return err;
}
/* Fill in our line protocol discipline */
static struct tty_ldisc sp_ldisc = {
.owner = THIS_MODULE,
.magic = TTY_LDISC_MAGIC,
......@@ -823,8 +825,10 @@ static struct tty_ldisc sp_ldisc = {
/* Initialize 6pack control device -- register 6pack line discipline */
static char msg_banner[] __initdata = KERN_INFO "AX.25: 6pack driver, " SIXPACK_VERSION "\n";
static char msg_regfail[] __initdata = KERN_ERR "6pack: can't register line discipline (err = %d)\n";
static char msg_banner[] __initdata = KERN_INFO \
"AX.25: 6pack driver, " SIXPACK_VERSION "\n";
static char msg_regfail[] __initdata = KERN_ERR \
"6pack: can't register line discipline (err = %d)\n";
static int __init sixpack_init_driver(void)
{
......@@ -839,7 +843,8 @@ static int __init sixpack_init_driver(void)
return status;
}
static const char msg_unregfail[] __exitdata = KERN_ERR "6pack: can't unregister line discipline (err = %d)\n";
static const char msg_unregfail[] __exitdata = KERN_ERR \
"6pack: can't unregister line discipline (err = %d)\n";
static void __exit sixpack_exit_driver(void)
{
......@@ -849,22 +854,6 @@ static void __exit sixpack_exit_driver(void)
printk(msg_unregfail, ret);
}
/* Initialize the 6pack driver. Called by DDI. */
static int sixpack_init(struct net_device *dev)
{
struct sixpack *sp = netdev_priv(dev);
if (sp == NULL) /* Allocation failed ?? */
return -ENODEV;
/* Set up the "6pack Control Block". (And clear statistics) */
memset(sp, 0, sizeof (struct sixpack));
sp->dev = dev;
return 0;
}
/* encode an AX.25 packet into 6pack */
static int encode_sixpack(unsigned char *tx_buf, unsigned char *tx_buf_raw,
......@@ -905,7 +894,7 @@ static int encode_sixpack(unsigned char *tx_buf, unsigned char *tx_buf_raw,
/* decode 4 sixpack-encoded bytes into 3 data bytes */
static void decode_data(unsigned char inbyte, struct sixpack *sp)
static void decode_data(struct sixpack *sp, unsigned char inbyte)
{
unsigned char *buf;
......@@ -927,7 +916,7 @@ static void decode_data(unsigned char inbyte, struct sixpack *sp)
/* identify and execute a 6pack priority command byte */
static void decode_prio_command(unsigned char cmd, struct sixpack *sp)
static void decode_prio_command(struct sixpack *sp, unsigned char cmd)
{
unsigned char channel;
int actual;
......@@ -971,11 +960,11 @@ static void decode_prio_command(unsigned char cmd, struct sixpack *sp)
/* if the state byte has been received, the TNC is present,
so the resync timer can be reset. */
if (sp->tnc_ok == 1) {
if (sp->tnc_state == TNC_IN_SYNC) {
del_timer(&sp->resync_t);
sp->resync_t.data = (unsigned long) sp;
sp->resync_t.function = resync_tnc;
sp->resync_t.expires = jiffies + SIXP_INIT_RESYNC_TIMEOUT;
sp->resync_t.data = (unsigned long) sp;
sp->resync_t.function = resync_tnc;
sp->resync_t.expires = jiffies + SIXP_INIT_RESYNC_TIMEOUT;
add_timer(&sp->resync_t);
}
......@@ -984,7 +973,7 @@ static void decode_prio_command(unsigned char cmd, struct sixpack *sp)
/* identify and execute a standard 6pack command byte */
static void decode_std_command(unsigned char cmd, struct sixpack *sp)
static void decode_std_command(struct sixpack *sp, unsigned char cmd)
{
unsigned char checksum = 0, rest = 0, channel;
short i;
......@@ -1005,7 +994,7 @@ static void decode_std_command(unsigned char cmd, struct sixpack *sp)
rest = sp->rx_count;
if (rest != 0)
for (i = rest; i <= 3; i++)
decode_data(0, sp);
decode_data(sp, 0);
if (rest == 2)
sp->rx_count_cooked -= 2;
else if (rest == 3)
......@@ -1033,7 +1022,7 @@ static void decode_std_command(unsigned char cmd, struct sixpack *sp)
/* decode a 6pack packet */
static void
sixpack_decode(struct sixpack *sp, unsigned char pre_rbuff[], int count)
sixpack_decode(struct sixpack *sp, unsigned char *pre_rbuff, int count)
{
unsigned char inbyte;
int count1;
......@@ -1041,16 +1030,15 @@ sixpack_decode(struct sixpack *sp, unsigned char pre_rbuff[], int count)
for (count1 = 0; count1 < count; count1++) {
inbyte = pre_rbuff[count1];
if (inbyte == SIXP_FOUND_TNC) {
printk(KERN_INFO "6pack: TNC found.\n");
sp->tnc_ok = 1;
tnc_set_sync_state(sp, TNC_IN_SYNC);
del_timer(&sp->resync_t);
}
if ((inbyte & SIXP_PRIO_CMD_MASK) != 0)
decode_prio_command(inbyte, sp);
decode_prio_command(sp, inbyte);
else if ((inbyte & SIXP_STD_CMD_MASK) != 0)
decode_std_command(inbyte, sp);
decode_std_command(sp, inbyte);
else if ((sp->status & SIXP_RX_DCD_MASK) == SIXP_RX_DCD_MASK)
decode_data(inbyte, sp);
decode_data(sp, inbyte);
}
}
......
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