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linux/net/irda/irnet/irnet_ppp.c

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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 "irnet_ppp.h" /* Private header */
/* Please put other headers in irnet.h - Thanks */
/* Generic PPP callbacks (to call us) */
static 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 */
while(isspace(*start))
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--;
/* 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 */
while(isspace(*begp))
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");
lock_kernel();
/* 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);
unlock_kernel();
return err;
}
/* For the control channel */
ap->event_index = irnet_events.index; /* Cancel all past events */
/* Put our stuff where we will be able to find it later */
file->private_data = ap;
DEXIT(FS_TRACE, " - ap=0x%p\n", ap);
unlock_kernel();
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 = (struct irnet_socket *) 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 = (struct irnet_socket *) 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 = (struct irnet_socket *) 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 = (struct irnet_socket *) 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 = (struct irnet_socket *) 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 configued in dev_irnet_open())*/
lock_kernel();
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");
unlock_kernel();
}
else
{
/* In theory, should be N_TTY */
DEBUG(FS_INFO, "Exiting PPP discipline.\n");
/* Disconnect from the generic PPP layer */
lock_kernel();
if(ap->ppp_open)
{
ap->ppp_open = 0;
ppp_unregister_channel(&ap->chan);
}
else
DERROR(FS_ERROR, "Channel not registered !\n");
err = 0;
unlock_kernel();
}
break;
/* Query PPP channel and unit number */
case PPPIOCGCHAN:
if(ap->ppp_open && !put_user(ppp_channel_index(&ap->chan),
(int __user *)argp))
err = 0;
break;
case PPPIOCGUNIT:
lock_kernel();
if(ap->ppp_open && !put_user(ppp_unit_number(&ap->chan),
(int __user *)argp))
err = 0;
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 {
lock_kernel();
err = ppp_irnet_ioctl(&ap->chan, cmd, arg);
unlock_kernel();
}
break;
/* TTY IOCTLs : Pretend that we are a tty, to keep pppd happy */
/* Get termios */
case TCGETS:
DEBUG(FS_INFO, "Get termios.\n");
lock_kernel();
#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
unlock_kernel();
break;
/* Set termios */
case TCSETSF:
DEBUG(FS_INFO, "Set termios.\n");
lock_kernel();
#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
unlock_kernel();
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
lock_kernel();
ppp_output_wakeup(&ap->chan);
unlock_kernel();
#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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