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linux/net/irda/irnet/irnet_ppp.c
Dan Rosenberg d50e7e3604 irda: prevent heap corruption on invalid nickname 
Invalid nicknames containing only spaces will result in an underflow in
a memcpy size calculation, subsequently destroying the heap and
panicking.

v2 also catches the case where the provided nickname is longer than the
buffer size, which can result in controllable heap corruption.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-27 17:59:02 -07:00

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/*
* IrNET protocol module : Synchronous PPP over an IrDA socket.
*
* Jean II - HPL `00 - <jt@hpl.hp.com>
*
* This file implement the PPP interface and /dev/irnet character device.
* The PPP interface hook to the ppp_generic module, handle all our
* relationship to the PPP code in the kernel (and by extension to pppd),
* and exchange PPP frames with this module (send/receive).
* The /dev/irnet device is used primarily for 2 functions :
* 1) as a stub for pppd (the ppp daemon), so that we can appropriately
* generate PPP sessions (we pretend we are a tty).
* 2) as a control channel (write commands, read events)
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include "irnet_ppp.h" /* Private header */
/* Please put other headers in irnet.h - Thanks */
/* Generic PPP callbacks (to call us) */
static const struct ppp_channel_ops irnet_ppp_ops = {
.start_xmit = ppp_irnet_send,
.ioctl = ppp_irnet_ioctl
};
/************************* CONTROL CHANNEL *************************/
/*
* When a pppd instance is not active on /dev/irnet, it acts as a control
* channel.
* Writing allow to set up the IrDA destination of the IrNET channel,
* and any application may be read events happening in IrNET...
*/
/*------------------------------------------------------------------*/
/*
* Write is used to send a command to configure a IrNET channel
* before it is open by pppd. The syntax is : "command argument"
* Currently there is only two defined commands :
* o name : set the requested IrDA nickname of the IrNET peer.
* o addr : set the requested IrDA address of the IrNET peer.
* Note : the code is crude, but effective...
*/
static inline ssize_t
irnet_ctrl_write(irnet_socket * ap,
const char __user *buf,
size_t count)
{
char command[IRNET_MAX_COMMAND];
char * start; /* Current command being processed */
char * next; /* Next command to process */
int length; /* Length of current command */
DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
/* Check for overflow... */
DABORT(count >= IRNET_MAX_COMMAND, -ENOMEM,
CTRL_ERROR, "Too much data !!!\n");
/* Get the data in the driver */
if(copy_from_user(command, buf, count))
{
DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
return -EFAULT;
}
/* Safe terminate the string */
command[count] = '\0';
DEBUG(CTRL_INFO, "Command line received is ``%s'' (%Zd).\n",
command, count);
/* Check every commands in the command line */
next = command;
while(next != NULL)
{
/* Look at the next command */
start = next;
/* Scrap whitespaces before the command */
start = skip_spaces(start);
/* ',' is our command separator */
next = strchr(start, ',');
if(next)
{
*next = '\0'; /* Terminate command */
length = next - start; /* Length */
next++; /* Skip the '\0' */
}
else
length = strlen(start);
DEBUG(CTRL_INFO, "Found command ``%s'' (%d).\n", start, length);
/* Check if we recognised one of the known command
* We can't use "switch" with strings, so hack with "continue" */
/* First command : name -> Requested IrDA nickname */
if(!strncmp(start, "name", 4))
{
/* Copy the name only if is included and not "any" */
if((length > 5) && (strcmp(start + 5, "any")))
{
/* Strip out trailing whitespaces */
while(isspace(start[length - 1]))
length--;
DABORT(length < 5 || length > NICKNAME_MAX_LEN + 5,
-EINVAL, CTRL_ERROR, "Invalid nickname.\n");
/* Copy the name for later reuse */
memcpy(ap->rname, start + 5, length - 5);
ap->rname[length - 5] = '\0';
}
else
ap->rname[0] = '\0';
DEBUG(CTRL_INFO, "Got rname = ``%s''\n", ap->rname);
/* Restart the loop */
continue;
}
/* Second command : addr, daddr -> Requested IrDA destination address
* Also process : saddr -> Requested IrDA source address */
if((!strncmp(start, "addr", 4)) ||
(!strncmp(start, "daddr", 5)) ||
(!strncmp(start, "saddr", 5)))
{
__u32 addr = DEV_ADDR_ANY;
/* Copy the address only if is included and not "any" */
if((length > 5) && (strcmp(start + 5, "any")))
{
char * begp = start + 5;
char * endp;
/* Scrap whitespaces before the command */
begp = skip_spaces(begp);
/* Convert argument to a number (last arg is the base) */
addr = simple_strtoul(begp, &endp, 16);
/* Has it worked ? (endp should be start + length) */
DABORT(endp <= (start + 5), -EINVAL,
CTRL_ERROR, "Invalid address.\n");
}
/* Which type of address ? */
if(start[0] == 's')
{
/* Save it */
ap->rsaddr = addr;
DEBUG(CTRL_INFO, "Got rsaddr = %08x\n", ap->rsaddr);
}
else
{
/* Save it */
ap->rdaddr = addr;
DEBUG(CTRL_INFO, "Got rdaddr = %08x\n", ap->rdaddr);
}
/* Restart the loop */
continue;
}
/* Other possible command : connect N (number of retries) */
/* No command matched -> Failed... */
DABORT(1, -EINVAL, CTRL_ERROR, "Not a recognised IrNET command.\n");
}
/* Success : we have parsed all commands successfully */
return count;
}
#ifdef INITIAL_DISCOVERY
/*------------------------------------------------------------------*/
/*
* Function irnet_get_discovery_log (self)
*
* Query the content on the discovery log if not done
*
* This function query the current content of the discovery log
* at the startup of the event channel and save it in the internal struct.
*/
static void
irnet_get_discovery_log(irnet_socket * ap)
{
__u16 mask = irlmp_service_to_hint(S_LAN);
/* Ask IrLMP for the current discovery log */
ap->discoveries = irlmp_get_discoveries(&ap->disco_number, mask,
DISCOVERY_DEFAULT_SLOTS);
/* Check if the we got some results */
if(ap->discoveries == NULL)
ap->disco_number = -1;
DEBUG(CTRL_INFO, "Got the log (0x%p), size is %d\n",
ap->discoveries, ap->disco_number);
}
/*------------------------------------------------------------------*/
/*
* Function irnet_read_discovery_log (self, event)
*
* Read the content on the discovery log
*
* This function dump the current content of the discovery log
* at the startup of the event channel.
* Return 1 if wrote an event on the control channel...
*
* State of the ap->disco_XXX variables :
* Socket creation : discoveries = NULL ; disco_index = 0 ; disco_number = 0
* While reading : discoveries = ptr ; disco_index = X ; disco_number = Y
* After reading : discoveries = NULL ; disco_index = Y ; disco_number = -1
*/
static inline int
irnet_read_discovery_log(irnet_socket * ap,
char * event)
{
int done_event = 0;
DENTER(CTRL_TRACE, "(ap=0x%p, event=0x%p)\n",
ap, event);
/* Test if we have some work to do or we have already finished */
if(ap->disco_number == -1)
{
DEBUG(CTRL_INFO, "Already done\n");
return 0;
}
/* Test if it's the first time and therefore we need to get the log */
if(ap->discoveries == NULL)
irnet_get_discovery_log(ap);
/* Check if we have more item to dump */
if(ap->disco_index < ap->disco_number)
{
/* Write an event */
sprintf(event, "Found %08x (%s) behind %08x {hints %02X-%02X}\n",
ap->discoveries[ap->disco_index].daddr,
ap->discoveries[ap->disco_index].info,
ap->discoveries[ap->disco_index].saddr,
ap->discoveries[ap->disco_index].hints[0],
ap->discoveries[ap->disco_index].hints[1]);
DEBUG(CTRL_INFO, "Writing discovery %d : %s\n",
ap->disco_index, ap->discoveries[ap->disco_index].info);
/* We have an event */
done_event = 1;
/* Next discovery */
ap->disco_index++;
}
/* Check if we have done the last item */
if(ap->disco_index >= ap->disco_number)
{
/* No more items : remove the log and signal termination */
DEBUG(CTRL_INFO, "Cleaning up log (0x%p)\n",
ap->discoveries);
if(ap->discoveries != NULL)
{
/* Cleanup our copy of the discovery log */
kfree(ap->discoveries);
ap->discoveries = NULL;
}
ap->disco_number = -1;
}
return done_event;
}
#endif /* INITIAL_DISCOVERY */
/*------------------------------------------------------------------*/
/*
* Read is used to get IrNET events
*/
static inline ssize_t
irnet_ctrl_read(irnet_socket * ap,
struct file * file,
char __user * buf,
size_t count)
{
DECLARE_WAITQUEUE(wait, current);
char event[64]; /* Max event is 61 char */
ssize_t ret = 0;
DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
/* Check if we can write an event out in one go */
DABORT(count < sizeof(event), -EOVERFLOW, CTRL_ERROR, "Buffer to small.\n");
#ifdef INITIAL_DISCOVERY
/* Check if we have read the log */
if(irnet_read_discovery_log(ap, event))
{
/* We have an event !!! Copy it to the user */
if(copy_to_user(buf, event, strlen(event)))
{
DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
return -EFAULT;
}
DEXIT(CTRL_TRACE, "\n");
return strlen(event);
}
#endif /* INITIAL_DISCOVERY */
/* Put ourselves on the wait queue to be woken up */
add_wait_queue(&irnet_events.rwait, &wait);
current->state = TASK_INTERRUPTIBLE;
for(;;)
{
/* If there is unread events */
ret = 0;
if(ap->event_index != irnet_events.index)
break;
ret = -EAGAIN;
if(file->f_flags & O_NONBLOCK)
break;
ret = -ERESTARTSYS;
if(signal_pending(current))
break;
/* Yield and wait to be woken up */
schedule();
}
current->state = TASK_RUNNING;
remove_wait_queue(&irnet_events.rwait, &wait);
/* Did we got it ? */
if(ret != 0)
{
/* No, return the error code */
DEXIT(CTRL_TRACE, " - ret %Zd\n", ret);
return ret;
}
/* Which event is it ? */
switch(irnet_events.log[ap->event_index].event)
{
case IRNET_DISCOVER:
sprintf(event, "Discovered %08x (%s) behind %08x {hints %02X-%02X}\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].saddr,
irnet_events.log[ap->event_index].hints.byte[0],
irnet_events.log[ap->event_index].hints.byte[1]);
break;
case IRNET_EXPIRE:
sprintf(event, "Expired %08x (%s) behind %08x {hints %02X-%02X}\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].saddr,
irnet_events.log[ap->event_index].hints.byte[0],
irnet_events.log[ap->event_index].hints.byte[1]);
break;
case IRNET_CONNECT_TO:
sprintf(event, "Connected to %08x (%s) on ppp%d\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].unit);
break;
case IRNET_CONNECT_FROM:
sprintf(event, "Connection from %08x (%s) on ppp%d\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].unit);
break;
case IRNET_REQUEST_FROM:
sprintf(event, "Request from %08x (%s) behind %08x\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].saddr);
break;
case IRNET_NOANSWER_FROM:
sprintf(event, "No-answer from %08x (%s) on ppp%d\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].unit);
break;
case IRNET_BLOCKED_LINK:
sprintf(event, "Blocked link with %08x (%s) on ppp%d\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].unit);
break;
case IRNET_DISCONNECT_FROM:
sprintf(event, "Disconnection from %08x (%s) on ppp%d\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name,
irnet_events.log[ap->event_index].unit);
break;
case IRNET_DISCONNECT_TO:
sprintf(event, "Disconnected to %08x (%s)\n",
irnet_events.log[ap->event_index].daddr,
irnet_events.log[ap->event_index].name);
break;
default:
sprintf(event, "Bug\n");
}
/* Increment our event index */
ap->event_index = (ap->event_index + 1) % IRNET_MAX_EVENTS;
DEBUG(CTRL_INFO, "Event is :%s", event);
/* Copy it to the user */
if(copy_to_user(buf, event, strlen(event)))
{
DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
return -EFAULT;
}
DEXIT(CTRL_TRACE, "\n");
return strlen(event);
}
/*------------------------------------------------------------------*/
/*
* Poll : called when someone do a select on /dev/irnet.
* Just check if there are new events...
*/
static inline unsigned int
irnet_ctrl_poll(irnet_socket * ap,
struct file * file,
poll_table * wait)
{
unsigned int mask;
DENTER(CTRL_TRACE, "(ap=0x%p)\n", ap);
poll_wait(file, &irnet_events.rwait, wait);
mask = POLLOUT | POLLWRNORM;
/* If there is unread events */
if(ap->event_index != irnet_events.index)
mask |= POLLIN | POLLRDNORM;
#ifdef INITIAL_DISCOVERY
if(ap->disco_number != -1)
{
/* Test if it's the first time and therefore we need to get the log */
if(ap->discoveries == NULL)
irnet_get_discovery_log(ap);
/* Recheck */
if(ap->disco_number != -1)
mask |= POLLIN | POLLRDNORM;
}
#endif /* INITIAL_DISCOVERY */
DEXIT(CTRL_TRACE, " - mask=0x%X\n", mask);
return mask;
}
/*********************** FILESYSTEM CALLBACKS ***********************/
/*
* Implement the usual open, read, write functions that will be called
* by the file system when some action is performed on /dev/irnet.
* Most of those actions will in fact be performed by "pppd" or
* the control channel, we just act as a redirector...
*/
/*------------------------------------------------------------------*/
/*
* Open : when somebody open /dev/irnet
* We basically create a new instance of irnet and initialise it.
*/
static int
dev_irnet_open(struct inode * inode,
struct file * file)
{
struct irnet_socket * ap;
int err;
DENTER(FS_TRACE, "(file=0x%p)\n", file);
#ifdef SECURE_DEVIRNET
/* This could (should?) be enforced by the permissions on /dev/irnet. */
if(!capable(CAP_NET_ADMIN))
return -EPERM;
#endif /* SECURE_DEVIRNET */
/* Allocate a private structure for this IrNET instance */
ap = kzalloc(sizeof(*ap), GFP_KERNEL);
DABORT(ap == NULL, -ENOMEM, FS_ERROR, "Can't allocate struct irnet...\n");
/* initialize the irnet structure */
ap->file = file;
/* PPP channel setup */
ap->ppp_open = 0;
ap->chan.private = ap;
ap->chan.ops = &irnet_ppp_ops;
ap->chan.mtu = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
ap->chan.hdrlen = 2 + TTP_MAX_HEADER; /* for A/C + Max IrDA hdr */
/* PPP parameters */
ap->mru = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
ap->xaccm[0] = ~0U;
ap->xaccm[3] = 0x60000000U;
ap->raccm = ~0U;
/* Setup the IrDA part... */
err = irda_irnet_create(ap);
if(err)
{
DERROR(FS_ERROR, "Can't setup IrDA link...\n");
kfree(ap);
return err;
}
/* For the control channel */
ap->event_index = irnet_events.index; /* Cancel all past events */
mutex_init(&ap->lock);
/* Put our stuff where we will be able to find it later */
file->private_data = ap;
DEXIT(FS_TRACE, " - ap=0x%p\n", ap);
return 0;
}
/*------------------------------------------------------------------*/
/*
* Close : when somebody close /dev/irnet
* Destroy the instance of /dev/irnet
*/
static int
dev_irnet_close(struct inode * inode,
struct file * file)
{
irnet_socket * ap = file->private_data;
DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
file, ap);
DABORT(ap == NULL, 0, FS_ERROR, "ap is NULL !!!\n");
/* Detach ourselves */
file->private_data = NULL;
/* Close IrDA stuff */
irda_irnet_destroy(ap);
/* Disconnect from the generic PPP layer if not already done */
if(ap->ppp_open)
{
DERROR(FS_ERROR, "Channel still registered - deregistering !\n");
ap->ppp_open = 0;
ppp_unregister_channel(&ap->chan);
}
kfree(ap);
DEXIT(FS_TRACE, "\n");
return 0;
}
/*------------------------------------------------------------------*/
/*
* Write does nothing.
* (we receive packet from ppp_generic through ppp_irnet_send())
*/
static ssize_t
dev_irnet_write(struct file * file,
const char __user *buf,
size_t count,
loff_t * ppos)
{
irnet_socket * ap = file->private_data;
DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
file, ap, count);
DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
/* If we are connected to ppp_generic, let it handle the job */
if(ap->ppp_open)
return -EAGAIN;
else
return irnet_ctrl_write(ap, buf, count);
}
/*------------------------------------------------------------------*/
/*
* Read doesn't do much either.
* (pppd poll us, but ultimately reads through /dev/ppp)
*/
static ssize_t
dev_irnet_read(struct file * file,
char __user * buf,
size_t count,
loff_t * ppos)
{
irnet_socket * ap = file->private_data;
DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
file, ap, count);
DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
/* If we are connected to ppp_generic, let it handle the job */
if(ap->ppp_open)
return -EAGAIN;
else
return irnet_ctrl_read(ap, file, buf, count);
}
/*------------------------------------------------------------------*/
/*
* Poll : called when someone do a select on /dev/irnet
*/
static unsigned int
dev_irnet_poll(struct file * file,
poll_table * wait)
{
irnet_socket * ap = file->private_data;
unsigned int mask;
DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
file, ap);
mask = POLLOUT | POLLWRNORM;
DABORT(ap == NULL, mask, FS_ERROR, "ap is NULL !!!\n");
/* If we are connected to ppp_generic, let it handle the job */
if(!ap->ppp_open)
mask |= irnet_ctrl_poll(ap, file, wait);
DEXIT(FS_TRACE, " - mask=0x%X\n", mask);
return mask;
}
/*------------------------------------------------------------------*/
/*
* IOCtl : Called when someone does some ioctls on /dev/irnet
* This is the way pppd configure us and control us while the PPP
* instance is active.
*/
static long
dev_irnet_ioctl(
struct file * file,
unsigned int cmd,
unsigned long arg)
{
irnet_socket * ap = file->private_data;
int err;
int val;
void __user *argp = (void __user *)arg;
DENTER(FS_TRACE, "(file=0x%p, ap=0x%p, cmd=0x%X)\n",
file, ap, cmd);
/* Basic checks... */
DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
#ifdef SECURE_DEVIRNET
if(!capable(CAP_NET_ADMIN))
return -EPERM;
#endif /* SECURE_DEVIRNET */
err = -EFAULT;
switch(cmd)
{
/* Set discipline (should be N_SYNC_PPP or N_TTY) */
case TIOCSETD:
if(get_user(val, (int __user *)argp))
break;
if((val == N_SYNC_PPP) || (val == N_PPP))
{
DEBUG(FS_INFO, "Entering PPP discipline.\n");
/* PPP channel setup (ap->chan in configured in dev_irnet_open())*/
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
err = ppp_register_channel(&ap->chan);
if(err == 0)
{
/* Our ppp side is active */
ap->ppp_open = 1;
DEBUG(FS_INFO, "Trying to establish a connection.\n");
/* Setup the IrDA link now - may fail... */
irda_irnet_connect(ap);
}
else
DERROR(FS_ERROR, "Can't setup PPP channel...\n");
mutex_unlock(&ap->lock);
}
else
{
/* In theory, should be N_TTY */
DEBUG(FS_INFO, "Exiting PPP discipline.\n");
/* Disconnect from the generic PPP layer */
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
if(ap->ppp_open)
{
ap->ppp_open = 0;
ppp_unregister_channel(&ap->chan);
}
else
DERROR(FS_ERROR, "Channel not registered !\n");
err = 0;
mutex_unlock(&ap->lock);
}
break;
/* Query PPP channel and unit number */
case PPPIOCGCHAN:
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
if(ap->ppp_open && !put_user(ppp_channel_index(&ap->chan),
(int __user *)argp))
err = 0;
mutex_unlock(&ap->lock);
break;
case PPPIOCGUNIT:
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
if(ap->ppp_open && !put_user(ppp_unit_number(&ap->chan),
(int __user *)argp))
err = 0;
mutex_unlock(&ap->lock);
break;
/* All these ioctls can be passed both directly and from ppp_generic,
* so we just deal with them in one place...
*/
case PPPIOCGFLAGS:
case PPPIOCSFLAGS:
case PPPIOCGASYNCMAP:
case PPPIOCSASYNCMAP:
case PPPIOCGRASYNCMAP:
case PPPIOCSRASYNCMAP:
case PPPIOCGXASYNCMAP:
case PPPIOCSXASYNCMAP:
case PPPIOCGMRU:
case PPPIOCSMRU:
DEBUG(FS_INFO, "Standard PPP ioctl.\n");
if(!capable(CAP_NET_ADMIN))
err = -EPERM;
else {
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
err = ppp_irnet_ioctl(&ap->chan, cmd, arg);
mutex_unlock(&ap->lock);
}
break;
/* TTY IOCTLs : Pretend that we are a tty, to keep pppd happy */
/* Get termios */
case TCGETS:
DEBUG(FS_INFO, "Get termios.\n");
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
#ifndef TCGETS2
if(!kernel_termios_to_user_termios((struct termios __user *)argp, &ap->termios))
err = 0;
#else
if(kernel_termios_to_user_termios_1((struct termios __user *)argp, &ap->termios))
err = 0;
#endif
mutex_unlock(&ap->lock);
break;
/* Set termios */
case TCSETSF:
DEBUG(FS_INFO, "Set termios.\n");
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
#ifndef TCGETS2
if(!user_termios_to_kernel_termios(&ap->termios, (struct termios __user *)argp))
err = 0;
#else
if(!user_termios_to_kernel_termios_1(&ap->termios, (struct termios __user *)argp))
err = 0;
#endif
mutex_unlock(&ap->lock);
break;
/* Set DTR/RTS */
case TIOCMBIS:
case TIOCMBIC:
/* Set exclusive/non-exclusive mode */
case TIOCEXCL:
case TIOCNXCL:
DEBUG(FS_INFO, "TTY compatibility.\n");
err = 0;
break;
case TCGETA:
DEBUG(FS_INFO, "TCGETA\n");
break;
case TCFLSH:
DEBUG(FS_INFO, "TCFLSH\n");
/* Note : this will flush buffers in PPP, so it *must* be done
* We should also worry that we don't accept junk here and that
* we get rid of our own buffers */
#ifdef FLUSH_TO_PPP
if (mutex_lock_interruptible(&ap->lock))
return -EINTR;
ppp_output_wakeup(&ap->chan);
mutex_unlock(&ap->lock);
#endif /* FLUSH_TO_PPP */
err = 0;
break;
case FIONREAD:
DEBUG(FS_INFO, "FIONREAD\n");
val = 0;
if(put_user(val, (int __user *)argp))
break;
err = 0;
break;
default:
DERROR(FS_ERROR, "Unsupported ioctl (0x%X)\n", cmd);
err = -ENOTTY;
}
DEXIT(FS_TRACE, " - err = 0x%X\n", err);
return err;
}
/************************** PPP CALLBACKS **************************/
/*
* This are the functions that the generic PPP driver in the kernel
* will call to communicate to us.
*/
/*------------------------------------------------------------------*/
/*
* Prepare the ppp frame for transmission over the IrDA socket.
* We make sure that the header space is enough, and we change ppp header
* according to flags passed by pppd.
* This is not a callback, but just a helper function used in ppp_irnet_send()
*/
static inline struct sk_buff *
irnet_prepare_skb(irnet_socket * ap,
struct sk_buff * skb)
{
unsigned char * data;
int proto; /* PPP protocol */
int islcp; /* Protocol == LCP */
int needaddr; /* Need PPP address */
DENTER(PPP_TRACE, "(ap=0x%p, skb=0x%p)\n",
ap, skb);
/* Extract PPP protocol from the frame */
data = skb->data;
proto = (data[0] << 8) + data[1];
/* LCP packets with codes between 1 (configure-request)
* and 7 (code-reject) must be sent as though no options
* have been negotiated. */
islcp = (proto == PPP_LCP) && (1 <= data[2]) && (data[2] <= 7);
/* compress protocol field if option enabled */
if((data[0] == 0) && (ap->flags & SC_COMP_PROT) && (!islcp))
skb_pull(skb,1);
/* Check if we need address/control fields */
needaddr = 2*((ap->flags & SC_COMP_AC) == 0 || islcp);
/* Is the skb headroom large enough to contain all IrDA-headers? */
if((skb_headroom(skb) < (ap->max_header_size + needaddr)) ||
(skb_shared(skb)))
{
struct sk_buff * new_skb;
DEBUG(PPP_INFO, "Reallocating skb\n");
/* Create a new skb */
new_skb = skb_realloc_headroom(skb, ap->max_header_size + needaddr);
/* We have to free the original skb anyway */
dev_kfree_skb(skb);
/* Did the realloc succeed ? */
DABORT(new_skb == NULL, NULL, PPP_ERROR, "Could not realloc skb\n");
/* Use the new skb instead */
skb = new_skb;
}
/* prepend address/control fields if necessary */
if(needaddr)
{
skb_push(skb, 2);
skb->data[0] = PPP_ALLSTATIONS;
skb->data[1] = PPP_UI;
}
DEXIT(PPP_TRACE, "\n");
return skb;
}
/*------------------------------------------------------------------*/
/*
* Send a packet to the peer over the IrTTP connection.
* Returns 1 iff the packet was accepted.
* Returns 0 iff packet was not consumed.
* If the packet was not accepted, we will call ppp_output_wakeup
* at some later time to reactivate flow control in ppp_generic.
*/
static int
ppp_irnet_send(struct ppp_channel * chan,
struct sk_buff * skb)
{
irnet_socket * self = (struct irnet_socket *) chan->private;
int ret;
DENTER(PPP_TRACE, "(channel=0x%p, ap/self=0x%p)\n",
chan, self);
/* Check if things are somewhat valid... */
DASSERT(self != NULL, 0, PPP_ERROR, "Self is NULL !!!\n");
/* Check if we are connected */
if(!(test_bit(0, &self->ttp_open)))
{
#ifdef CONNECT_IN_SEND
/* Let's try to connect one more time... */
/* Note : we won't be connected after this call, but we should be
* ready for next packet... */
/* If we are already connecting, this will fail */
irda_irnet_connect(self);
#endif /* CONNECT_IN_SEND */
DEBUG(PPP_INFO, "IrTTP not ready ! (%ld-%ld)\n",
self->ttp_open, self->ttp_connect);
/* Note : we can either drop the packet or block the packet.
*
* Blocking the packet allow us a better connection time,
* because by calling ppp_output_wakeup() we can have
* ppp_generic resending the LCP request immediately to us,
* rather than waiting for one of pppd periodic transmission of
* LCP request.
*
* On the other hand, if we block all packet, all those periodic
* transmissions of pppd accumulate in ppp_generic, creating a
* backlog of LCP request. When we eventually connect later on,
* we have to transmit all this backlog before we can connect
* proper (if we don't timeout before).
*
* The current strategy is as follow :
* While we are attempting to connect, we block packets to get
* a better connection time.
* If we fail to connect, we drain the queue and start dropping packets
*/
#ifdef BLOCK_WHEN_CONNECT
/* If we are attempting to connect */
if(test_bit(0, &self->ttp_connect))
{
/* Blocking packet, ppp_generic will retry later */
return 0;
}
#endif /* BLOCK_WHEN_CONNECT */
/* Dropping packet, pppd will retry later */
dev_kfree_skb(skb);
return 1;
}
/* Check if the queue can accept any packet, otherwise block */
if(self->tx_flow != FLOW_START)
DRETURN(0, PPP_INFO, "IrTTP queue full (%d skbs)...\n",
skb_queue_len(&self->tsap->tx_queue));
/* Prepare ppp frame for transmission */
skb = irnet_prepare_skb(self, skb);
DABORT(skb == NULL, 1, PPP_ERROR, "Prepare skb for Tx failed.\n");
/* Send the packet to IrTTP */
ret = irttp_data_request(self->tsap, skb);
if(ret < 0)
{
/*
* > IrTTPs tx queue is full, so we just have to
* > drop the frame! You might think that we should
* > just return -1 and don't deallocate the frame,
* > but that is dangerous since it's possible that
* > we have replaced the original skb with a new
* > one with larger headroom, and that would really
* > confuse do_dev_queue_xmit() in dev.c! I have
* > tried :-) DB
* Correction : we verify the flow control above (self->tx_flow),
* so we come here only if IrTTP doesn't like the packet (empty,
* too large, IrTTP not connected). In those rare cases, it's ok
* to drop it, we don't want to see it here again...
* Jean II
*/
DERROR(PPP_ERROR, "IrTTP doesn't like this packet !!! (0x%X)\n", ret);
/* irttp_data_request already free the packet */
}
DEXIT(PPP_TRACE, "\n");
return 1; /* Packet has been consumed */
}
/*------------------------------------------------------------------*/
/*
* Take care of the ioctls that ppp_generic doesn't want to deal with...
* Note : we are also called from dev_irnet_ioctl().
*/
static int
ppp_irnet_ioctl(struct ppp_channel * chan,
unsigned int cmd,
unsigned long arg)
{
irnet_socket * ap = (struct irnet_socket *) chan->private;
int err;
int val;
u32 accm[8];
void __user *argp = (void __user *)arg;
DENTER(PPP_TRACE, "(channel=0x%p, ap=0x%p, cmd=0x%X)\n",
chan, ap, cmd);
/* Basic checks... */
DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
err = -EFAULT;
switch(cmd)
{
/* PPP flags */
case PPPIOCGFLAGS:
val = ap->flags | ap->rbits;
if(put_user(val, (int __user *) argp))
break;
err = 0;
break;
case PPPIOCSFLAGS:
if(get_user(val, (int __user *) argp))
break;
ap->flags = val & ~SC_RCV_BITS;
ap->rbits = val & SC_RCV_BITS;
err = 0;
break;
/* Async map stuff - all dummy to please pppd */
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;
/* Max PPP frame size */
case PPPIOCGMRU:
if(put_user(ap->mru, (int __user *) argp))
break;
err = 0;
break;
case PPPIOCSMRU:
if(get_user(val, (int __user *) argp))
break;
if(val < PPP_MRU)
val = PPP_MRU;
ap->mru = val;
err = 0;
break;
default:
DEBUG(PPP_INFO, "Unsupported ioctl (0x%X)\n", cmd);
err = -ENOIOCTLCMD;
}
DEXIT(PPP_TRACE, " - err = 0x%X\n", err);
return err;
}
/************************** INITIALISATION **************************/
/*
* Module initialisation and all that jazz...
*/
/*------------------------------------------------------------------*/
/*
* Hook our device callbacks in the filesystem, to connect our code
* to /dev/irnet
*/
static inline int __init
ppp_irnet_init(void)
{
int err = 0;
DENTER(MODULE_TRACE, "()\n");
/* Allocate ourselves as a minor in the misc range */
err = misc_register(&irnet_misc_device);
DEXIT(MODULE_TRACE, "\n");
return err;
}
/*------------------------------------------------------------------*/
/*
* Cleanup at exit...
*/
static inline void __exit
ppp_irnet_cleanup(void)
{
DENTER(MODULE_TRACE, "()\n");
/* De-allocate /dev/irnet minor in misc range */
misc_deregister(&irnet_misc_device);
DEXIT(MODULE_TRACE, "\n");
}
/*------------------------------------------------------------------*/
/*
* Module main entry point
*/
static int __init
irnet_init(void)
{
int err;
/* Initialise both parts... */
err = irda_irnet_init();
if(!err)
err = ppp_irnet_init();
return err;
}
/*------------------------------------------------------------------*/
/*
* Module exit
*/
static void __exit
irnet_cleanup(void)
{
irda_irnet_cleanup();
ppp_irnet_cleanup();
}
/*------------------------------------------------------------------*/
/*
* Module magic
*/
module_init(irnet_init);
module_exit(irnet_cleanup);
MODULE_AUTHOR("Jean Tourrilhes <jt@hpl.hp.com>");
MODULE_DESCRIPTION("IrNET : Synchronous PPP over IrDA");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV(10, 187);
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