linux/drivers/tty/ipwireless/network.c
Alan Cox d1519e23c2 ipwireless: don't oops if we run out of space
Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=49851

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 16:53:15 -08:00

517 lines
13 KiB
C

/*
* IPWireless 3G PCMCIA Network Driver
*
* Original code
* by Stephen Blackheath <stephen@blacksapphire.com>,
* Ben Martel <benm@symmetric.co.nz>
*
* Copyrighted as follows:
* Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
*
* Various driver changes and rewrites, port to new kernels
* Copyright (C) 2006-2007 Jiri Kosina
*
* Misc code cleanups and updates
* Copyright (C) 2007 David Sterba
*/
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/ppp_channel.h>
#include <linux/ppp_defs.h>
#include <linux/slab.h>
#include <linux/ppp-ioctl.h>
#include <linux/skbuff.h>
#include "network.h"
#include "hardware.h"
#include "main.h"
#include "tty.h"
#define MAX_ASSOCIATED_TTYS 2
#define SC_RCV_BITS (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
struct ipw_network {
/* Hardware context, used for calls to hardware layer. */
struct ipw_hardware *hardware;
/* Context for kernel 'generic_ppp' functionality */
struct ppp_channel *ppp_channel;
/* tty context connected with IPW console */
struct ipw_tty *associated_ttys[NO_OF_IPW_CHANNELS][MAX_ASSOCIATED_TTYS];
/* True if ppp needs waking up once we're ready to xmit */
int ppp_blocked;
/* Number of packets queued up in hardware module. */
int outgoing_packets_queued;
/* Spinlock to avoid interrupts during shutdown */
spinlock_t lock;
struct mutex close_lock;
/* PPP ioctl data, not actually used anywere */
unsigned int flags;
unsigned int rbits;
u32 xaccm[8];
u32 raccm;
int mru;
int shutting_down;
unsigned int ras_control_lines;
struct work_struct work_go_online;
struct work_struct work_go_offline;
};
static void notify_packet_sent(void *callback_data, unsigned int packet_length)
{
struct ipw_network *network = callback_data;
unsigned long flags;
spin_lock_irqsave(&network->lock, flags);
network->outgoing_packets_queued--;
if (network->ppp_channel != NULL) {
if (network->ppp_blocked) {
network->ppp_blocked = 0;
spin_unlock_irqrestore(&network->lock, flags);
ppp_output_wakeup(network->ppp_channel);
if (ipwireless_debug)
printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
": ppp unblocked\n");
} else
spin_unlock_irqrestore(&network->lock, flags);
} else
spin_unlock_irqrestore(&network->lock, flags);
}
/*
* Called by the ppp system when it has a packet to send to the hardware.
*/
static int ipwireless_ppp_start_xmit(struct ppp_channel *ppp_channel,
struct sk_buff *skb)
{
struct ipw_network *network = ppp_channel->private;
unsigned long flags;
spin_lock_irqsave(&network->lock, flags);
if (network->outgoing_packets_queued < ipwireless_out_queue) {
unsigned char *buf;
static unsigned char header[] = {
PPP_ALLSTATIONS, /* 0xff */
PPP_UI, /* 0x03 */
};
int ret;
network->outgoing_packets_queued++;
spin_unlock_irqrestore(&network->lock, flags);
/*
* If we have the requested amount of headroom in the skb we
* were handed, then we can add the header efficiently.
*/
if (skb_headroom(skb) >= 2) {
memcpy(skb_push(skb, 2), header, 2);
ret = ipwireless_send_packet(network->hardware,
IPW_CHANNEL_RAS, skb->data,
skb->len,
notify_packet_sent,
network);
if (ret == -1) {
skb_pull(skb, 2);
return 0;
}
} else {
/* Otherwise (rarely) we do it inefficiently. */
buf = kmalloc(skb->len + 2, GFP_ATOMIC);
if (!buf)
return 0;
memcpy(buf + 2, skb->data, skb->len);
memcpy(buf, header, 2);
ret = ipwireless_send_packet(network->hardware,
IPW_CHANNEL_RAS, buf,
skb->len + 2,
notify_packet_sent,
network);
kfree(buf);
if (ret == -1)
return 0;
}
kfree_skb(skb);
return 1;
} else {
/*
* Otherwise reject the packet, and flag that the ppp system
* needs to be unblocked once we are ready to send.
*/
network->ppp_blocked = 1;
spin_unlock_irqrestore(&network->lock, flags);
if (ipwireless_debug)
printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": ppp blocked\n");
return 0;
}
}
/* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
unsigned int cmd, unsigned long arg)
{
struct ipw_network *network = ppp_channel->private;
int err, val;
u32 accm[8];
int __user *user_arg = (int __user *) arg;
err = -EFAULT;
switch (cmd) {
case PPPIOCGFLAGS:
val = network->flags | network->rbits;
if (put_user(val, user_arg))
break;
err = 0;
break;
case PPPIOCSFLAGS:
if (get_user(val, user_arg))
break;
network->flags = val & ~SC_RCV_BITS;
network->rbits = val & SC_RCV_BITS;
err = 0;
break;
case PPPIOCGASYNCMAP:
if (put_user(network->xaccm[0], user_arg))
break;
err = 0;
break;
case PPPIOCSASYNCMAP:
if (get_user(network->xaccm[0], user_arg))
break;
err = 0;
break;
case PPPIOCGRASYNCMAP:
if (put_user(network->raccm, user_arg))
break;
err = 0;
break;
case PPPIOCSRASYNCMAP:
if (get_user(network->raccm, user_arg))
break;
err = 0;
break;
case PPPIOCGXASYNCMAP:
if (copy_to_user((void __user *) arg, network->xaccm,
sizeof(network->xaccm)))
break;
err = 0;
break;
case PPPIOCSXASYNCMAP:
if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
break;
accm[2] &= ~0x40000000U; /* can't escape 0x5e */
accm[3] |= 0x60000000U; /* must escape 0x7d, 0x7e */
memcpy(network->xaccm, accm, sizeof(network->xaccm));
err = 0;
break;
case PPPIOCGMRU:
if (put_user(network->mru, user_arg))
break;
err = 0;
break;
case PPPIOCSMRU:
if (get_user(val, user_arg))
break;
if (val < PPP_MRU)
val = PPP_MRU;
network->mru = val;
err = 0;
break;
default:
err = -ENOTTY;
}
return err;
}
static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
.start_xmit = ipwireless_ppp_start_xmit,
.ioctl = ipwireless_ppp_ioctl
};
static void do_go_online(struct work_struct *work_go_online)
{
struct ipw_network *network =
container_of(work_go_online, struct ipw_network,
work_go_online);
unsigned long flags;
spin_lock_irqsave(&network->lock, flags);
if (!network->ppp_channel) {
struct ppp_channel *channel;
spin_unlock_irqrestore(&network->lock, flags);
channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
if (!channel) {
printk(KERN_ERR IPWIRELESS_PCCARD_NAME
": unable to allocate PPP channel\n");
return;
}
channel->private = network;
channel->mtu = 16384; /* Wild guess */
channel->hdrlen = 2;
channel->ops = &ipwireless_ppp_channel_ops;
network->flags = 0;
network->rbits = 0;
network->mru = PPP_MRU;
memset(network->xaccm, 0, sizeof(network->xaccm));
network->xaccm[0] = ~0U;
network->xaccm[3] = 0x60000000U;
network->raccm = ~0U;
if (ppp_register_channel(channel) < 0) {
printk(KERN_ERR IPWIRELESS_PCCARD_NAME
": unable to register PPP channel\n");
kfree(channel);
return;
}
spin_lock_irqsave(&network->lock, flags);
network->ppp_channel = channel;
}
spin_unlock_irqrestore(&network->lock, flags);
}
static void do_go_offline(struct work_struct *work_go_offline)
{
struct ipw_network *network =
container_of(work_go_offline, struct ipw_network,
work_go_offline);
unsigned long flags;
mutex_lock(&network->close_lock);
spin_lock_irqsave(&network->lock, flags);
if (network->ppp_channel != NULL) {
struct ppp_channel *channel = network->ppp_channel;
network->ppp_channel = NULL;
spin_unlock_irqrestore(&network->lock, flags);
mutex_unlock(&network->close_lock);
ppp_unregister_channel(channel);
} else {
spin_unlock_irqrestore(&network->lock, flags);
mutex_unlock(&network->close_lock);
}
}
void ipwireless_network_notify_control_line_change(struct ipw_network *network,
unsigned int channel_idx,
unsigned int control_lines,
unsigned int changed_mask)
{
int i;
if (channel_idx == IPW_CHANNEL_RAS)
network->ras_control_lines = control_lines;
for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
struct ipw_tty *tty =
network->associated_ttys[channel_idx][i];
/*
* If it's associated with a tty (other than the RAS channel
* when we're online), then send the data to that tty. The RAS
* channel's data is handled above - it always goes through
* ppp_generic.
*/
if (tty)
ipwireless_tty_notify_control_line_change(tty,
channel_idx,
control_lines,
changed_mask);
}
}
/*
* Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
* bytes, which are required on sent packet, but not always present on received
* packets
*/
static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
unsigned int length)
{
struct sk_buff *skb;
if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
length -= 2;
data += 2;
}
skb = dev_alloc_skb(length + 4);
if (skb == NULL)
return NULL;
skb_reserve(skb, 2);
memcpy(skb_put(skb, length), data, length);
return skb;
}
void ipwireless_network_packet_received(struct ipw_network *network,
unsigned int channel_idx,
unsigned char *data,
unsigned int length)
{
int i;
unsigned long flags;
for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
if (!tty)
continue;
/*
* If it's associated with a tty (other than the RAS channel
* when we're online), then send the data to that tty. The RAS
* channel's data is handled above - it always goes through
* ppp_generic.
*/
if (channel_idx == IPW_CHANNEL_RAS
&& (network->ras_control_lines &
IPW_CONTROL_LINE_DCD) != 0
&& ipwireless_tty_is_modem(tty)) {
/*
* If data came in on the RAS channel and this tty is
* the modem tty, and we are online, then we send it to
* the PPP layer.
*/
mutex_lock(&network->close_lock);
spin_lock_irqsave(&network->lock, flags);
if (network->ppp_channel != NULL) {
struct sk_buff *skb;
spin_unlock_irqrestore(&network->lock,
flags);
/* Send the data to the ppp_generic module. */
skb = ipw_packet_received_skb(data, length);
if (skb)
ppp_input(network->ppp_channel, skb);
} else
spin_unlock_irqrestore(&network->lock,
flags);
mutex_unlock(&network->close_lock);
}
/* Otherwise we send it out the tty. */
else
ipwireless_tty_received(tty, data, length);
}
}
struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
{
struct ipw_network *network =
kzalloc(sizeof(struct ipw_network), GFP_ATOMIC);
if (!network)
return NULL;
spin_lock_init(&network->lock);
mutex_init(&network->close_lock);
network->hardware = hw;
INIT_WORK(&network->work_go_online, do_go_online);
INIT_WORK(&network->work_go_offline, do_go_offline);
ipwireless_associate_network(hw, network);
return network;
}
void ipwireless_network_free(struct ipw_network *network)
{
network->shutting_down = 1;
ipwireless_ppp_close(network);
flush_work(&network->work_go_online);
flush_work(&network->work_go_offline);
ipwireless_stop_interrupts(network->hardware);
ipwireless_associate_network(network->hardware, NULL);
kfree(network);
}
void ipwireless_associate_network_tty(struct ipw_network *network,
unsigned int channel_idx,
struct ipw_tty *tty)
{
int i;
for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
if (network->associated_ttys[channel_idx][i] == NULL) {
network->associated_ttys[channel_idx][i] = tty;
break;
}
}
void ipwireless_disassociate_network_ttys(struct ipw_network *network,
unsigned int channel_idx)
{
int i;
for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
network->associated_ttys[channel_idx][i] = NULL;
}
void ipwireless_ppp_open(struct ipw_network *network)
{
if (ipwireless_debug)
printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
schedule_work(&network->work_go_online);
}
void ipwireless_ppp_close(struct ipw_network *network)
{
/* Disconnect from the wireless network. */
if (ipwireless_debug)
printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
schedule_work(&network->work_go_offline);
}
int ipwireless_ppp_channel_index(struct ipw_network *network)
{
int ret = -1;
unsigned long flags;
spin_lock_irqsave(&network->lock, flags);
if (network->ppp_channel != NULL)
ret = ppp_channel_index(network->ppp_channel);
spin_unlock_irqrestore(&network->lock, flags);
return ret;
}
int ipwireless_ppp_unit_number(struct ipw_network *network)
{
int ret = -1;
unsigned long flags;
spin_lock_irqsave(&network->lock, flags);
if (network->ppp_channel != NULL)
ret = ppp_unit_number(network->ppp_channel);
spin_unlock_irqrestore(&network->lock, flags);
return ret;
}
int ipwireless_ppp_mru(const struct ipw_network *network)
{
return network->mru;
}