af_rose.c

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/*
 *	ROSE release 003
 *
 *	This code REQUIRES 2.1.15 or higher/ NET3.038
 *
 *	This module:
 *		This module 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.
 *
 *	History
 *	ROSE 001	Jonathan(G4KLX)	Cloned from af_netrom.c.
 *			Alan(GW4PTS)	Hacked up for newer API stuff
 *			Terry (VK2KTJ)	Added support for variable length
 * 					address masks.
 *	ROSE 002	Jonathan(G4KLX)	Changed hdrincl to qbitincl.
 *					Added random number facilities entry.
 *					Variable number of ROSE devices.
 *	ROSE 003	Jonathan(G4KLX)	New timer architecture.
 *					Implemented idle timer.
 *					Added use count to neighbour.
 *                      Tomi(OH2BNS)    Fixed rose_getname().
 *                      Arnaldo C. Melo s/suser/capable/ + micro cleanups
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/stat.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/termios.h>	/* For TIOCINQ/OUTQ */
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <net/rose.h>
#include <linux/proc_fs.h>
#include <net/ip.h>
#include <net/arp.h>

int rose_ndevs = 10;

int sysctl_rose_restart_request_timeout = ROSE_DEFAULT_T0;
int sysctl_rose_call_request_timeout    = ROSE_DEFAULT_T1;
int sysctl_rose_reset_request_timeout   = ROSE_DEFAULT_T2;
int sysctl_rose_clear_request_timeout   = ROSE_DEFAULT_T3;
int sysctl_rose_no_activity_timeout     = ROSE_DEFAULT_IDLE;
int sysctl_rose_ack_hold_back_timeout   = ROSE_DEFAULT_HB;
int sysctl_rose_routing_control         = ROSE_DEFAULT_ROUTING;
int sysctl_rose_link_fail_timeout       = ROSE_DEFAULT_FAIL_TIMEOUT;
int sysctl_rose_maximum_vcs             = ROSE_DEFAULT_MAXVC;
int sysctl_rose_window_size             = ROSE_DEFAULT_WINDOW_SIZE;

static struct sock *volatile rose_list = NULL;

static struct proto_ops rose_proto_ops;

ax25_address rose_callsign;

/*
 *	Convert a ROSE address into text.
 */
char *rose2asc(rose_address *addr)
{
	static char buffer[11];

	if (addr->rose_addr[0] == 0x00 && addr->rose_addr[1] == 0x00 &&
	    addr->rose_addr[2] == 0x00 && addr->rose_addr[3] == 0x00 &&
	    addr->rose_addr[4] == 0x00) {
		strcpy(buffer, "*");
	} else {
		sprintf(buffer, "%02X%02X%02X%02X%02X", addr->rose_addr[0] & 0xFF,
						addr->rose_addr[1] & 0xFF,
						addr->rose_addr[2] & 0xFF,
						addr->rose_addr[3] & 0xFF,
						addr->rose_addr[4] & 0xFF);
	}

	return buffer;
}

/*
 *	Compare two ROSE addresses, 0 == equal.
 */
int rosecmp(rose_address *addr1, rose_address *addr2)
{
	int i;

	for (i = 0; i < 5; i++)
		if (addr1->rose_addr[i] != addr2->rose_addr[i])
			return 1;

	return 0;
}

/*
 *	Compare two ROSE addresses for only mask digits, 0 == equal.
 */
int rosecmpm(rose_address *addr1, rose_address *addr2, unsigned short mask)
{
	int i, j;

	if (mask > 10)
		return 1;

	for (i = 0; i < mask; i++) {
		j = i / 2;

		if ((i % 2) != 0) {
			if ((addr1->rose_addr[j] & 0x0F) != (addr2->rose_addr[j] & 0x0F))
				return 1;
		} else {
			if ((addr1->rose_addr[j] & 0xF0) != (addr2->rose_addr[j] & 0xF0))
				return 1;
		}
	}

	return 0;
}

static void rose_free_sock(struct sock *sk)
{
	sk_free(sk);

	MOD_DEC_USE_COUNT;
}

static struct sock *rose_alloc_sock(void)
{
	struct sock *sk;
	rose_cb *rose;

	if ((sk = sk_alloc(PF_ROSE, GFP_ATOMIC, 1)) == NULL)
		return NULL;

	if ((rose = kmalloc(sizeof(*rose), GFP_ATOMIC)) == NULL) {
		sk_free(sk);
		return NULL;
	}

	MOD_INC_USE_COUNT;

	memset(rose, 0x00, sizeof(*rose));

	sk->protinfo.rose = rose;
	rose->sk          = sk;

	return sk;
}

/*
 *	Socket removal during an interrupt is now safe.
 */
static void rose_remove_socket(struct sock *sk)
{
	struct sock *s;
	unsigned long flags;

	save_flags(flags); cli();

	if ((s = rose_list) == sk) {
		rose_list = s->next;
		restore_flags(flags);
		return;
	}

	while (s != NULL && s->next != NULL) {
		if (s->next == sk) {
			s->next = sk->next;
			restore_flags(flags);
			return;
		}

		s = s->next;
	}

	restore_flags(flags);
}

/*
 *	Kill all bound sockets on a broken link layer connection to a
 *	particular neighbour.
 */
void rose_kill_by_neigh(struct rose_neigh *neigh)
{
	struct sock *s;

	for (s = rose_list; s != NULL; s = s->next) {
		if (s->protinfo.rose->neighbour == neigh) {
			rose_disconnect(s, ENETUNREACH, ROSE_OUT_OF_ORDER, 0);
			s->protinfo.rose->neighbour->use--;
			s->protinfo.rose->neighbour = NULL;
		}
	}
}

/*
 *	Kill all bound sockets on a dropped device.
 */
static void rose_kill_by_device(struct net_device *dev)
{
	struct sock *s;
	
	for (s = rose_list; s != NULL; s = s->next) {
		if (s->protinfo.rose->device == dev) {
			rose_disconnect(s, ENETUNREACH, ROSE_OUT_OF_ORDER, 0);
			s->protinfo.rose->neighbour->use--;
			s->protinfo.rose->device = NULL;
		}
	}
}

/*
 *	Handle device status changes.
 */
static int rose_device_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct net_device *dev = (struct net_device *)ptr;

	if (event != NETDEV_DOWN)
		return NOTIFY_DONE;

	switch (dev->type) {
		case ARPHRD_ROSE:
			rose_kill_by_device(dev);
			break;
		case ARPHRD_AX25:
			rose_link_device_down(dev);
			rose_rt_device_down(dev);
			break;
	}

	return NOTIFY_DONE;
}

/*
 *	Add a socket to the bound sockets list.
 */
static void rose_insert_socket(struct sock *sk)
{
	unsigned long flags;

	save_flags(flags); cli();

	sk->next  = rose_list;
	rose_list = sk;

	restore_flags(flags);
}

/*
 *	Find a socket that wants to accept the Call Request we just
 *	received.
 */
static struct sock *rose_find_listener(rose_address *addr, ax25_address *call)
{
	unsigned long flags;
	struct sock *s;

	save_flags(flags); cli();

	for (s = rose_list; s != NULL; s = s->next) {
		if (rosecmp(&s->protinfo.rose->source_addr, addr) == 0 && ax25cmp(&s->protinfo.rose->source_call, call) == 0 && s->protinfo.rose->source_ndigis == 0 && s->state == TCP_LISTEN) {
			restore_flags(flags);
			return s;
		}
	}

	for (s = rose_list; s != NULL; s = s->next) {
		if (rosecmp(&s->protinfo.rose->source_addr, addr) == 0 && ax25cmp(&s->protinfo.rose->source_call, &null_ax25_address) == 0 && s->state == TCP_LISTEN) {
			restore_flags(flags);
			return s;
		}
	}

	restore_flags(flags);
	return NULL;
}

/*
 *	Find a connected ROSE socket given my LCI and device.
 */
struct sock *rose_find_socket(unsigned int lci, struct rose_neigh *neigh)
{
	struct sock *s;
	unsigned long flags;

	save_flags(flags); cli();

	for (s = rose_list; s != NULL; s = s->next) {
		if (s->protinfo.rose->lci == lci && s->protinfo.rose->neighbour == neigh) {
			restore_flags(flags);
			return s;
		}
	}

	restore_flags(flags);

	return NULL;
}

/*
 *	Find a unique LCI for a given device.
 */
unsigned int rose_new_lci(struct rose_neigh *neigh)
{
	int lci;

	if (neigh->dce_mode) {
		for (lci = 1; lci <= sysctl_rose_maximum_vcs; lci++)
			if (rose_find_socket(lci, neigh) == NULL && rose_route_free_lci(lci, neigh) == NULL)
				return lci;
	} else {
		for (lci = sysctl_rose_maximum_vcs; lci > 0; lci--)
			if (rose_find_socket(lci, neigh) == NULL && rose_route_free_lci(lci, neigh) == NULL)
				return lci;
	}

	return 0;
}

/*
 *	Deferred destroy.
 */
void rose_destroy_socket(struct sock *);

/*
 *	Handler for deferred kills.
 */
static void rose_destroy_timer(unsigned long data)
{
	rose_destroy_socket((struct sock *)data);
}

/*
 *	This is called from user mode and the timers. Thus it protects itself against
 *	interrupt users but doesn't worry about being called during work.
 *	Once it is removed from the queue no interrupt or bottom half will
 *	touch it and we are (fairly 8-) ) safe.
 */
void rose_destroy_socket(struct sock *sk)	/* Not static as it's used by the timer */
{
	struct sk_buff *skb;
	unsigned long flags;

	save_flags(flags); cli();

	rose_stop_heartbeat(sk);
	rose_stop_idletimer(sk);
	rose_stop_timer(sk);

	rose_remove_socket(sk);
	rose_clear_queues(sk);		/* Flush the queues */

	while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) {
		if (skb->sk != sk) {			/* A pending connection */
			skb->sk->dead = 1;	/* Queue the unaccepted socket for death */
			rose_start_heartbeat(skb->sk);
			skb->sk->protinfo.rose->state = ROSE_STATE_0;
		}

		kfree_skb(skb);
	}

	if (atomic_read(&sk->wmem_alloc) != 0 || atomic_read(&sk->rmem_alloc) != 0) {
		/* Defer: outstanding buffers */
		init_timer(&sk->timer);
		sk->timer.expires  = jiffies + 10 * HZ;
		sk->timer.function = rose_destroy_timer;
		sk->timer.data     = (unsigned long)sk;
		add_timer(&sk->timer);
	} else {
		rose_free_sock(sk);
	}

	restore_flags(flags);
}

/*
 *	Handling for system calls applied via the various interfaces to a
 *	ROSE socket object.
 */

static int rose_setsockopt(struct socket *sock, int level, int optname,
	char *optval, int optlen)
{
	struct sock *sk = sock->sk;
	int opt;

	if (level != SOL_ROSE)
		return -ENOPROTOOPT;

	if (optlen < sizeof(int))
		return -EINVAL;

	if (get_user(opt, (int *)optval))
		return -EFAULT;

	switch (optname) {
		case ROSE_DEFER:
			sk->protinfo.rose->defer = opt ? 1 : 0;
			return 0;

		case ROSE_T1:
			if (opt < 1)
				return -EINVAL;
			sk->protinfo.rose->t1 = opt * HZ;
			return 0;

		case ROSE_T2:
			if (opt < 1)
				return -EINVAL;
			sk->protinfo.rose->t2 = opt * HZ;
			return 0;

		case ROSE_T3:
			if (opt < 1)
				return -EINVAL;
			sk->protinfo.rose->t3 = opt * HZ;
			return 0;

		case ROSE_HOLDBACK:
			if (opt < 1)
				return -EINVAL;
			sk->protinfo.rose->hb = opt * HZ;
			return 0;

		case ROSE_IDLE:
			if (opt < 0)
				return -EINVAL;
			sk->protinfo.rose->idle = opt * 60 * HZ;
			return 0;

		case ROSE_QBITINCL:
			sk->protinfo.rose->qbitincl = opt ? 1 : 0;
			return 0;

		default:
			return -ENOPROTOOPT;
	}
}

static int rose_getsockopt(struct socket *sock, int level, int optname,
	char *optval, int *optlen)
{
	struct sock *sk = sock->sk;
	int val = 0;
	int len;

	if (level != SOL_ROSE)
		return -ENOPROTOOPT;
		
	if (get_user(len, optlen))
		return -EFAULT;
	
	switch (optname) {
		case ROSE_DEFER:
			val = sk->protinfo.rose->defer;
			break;

		case ROSE_T1:
			val = sk->protinfo.rose->t1 / HZ;
			break;

		case ROSE_T2:
			val = sk->protinfo.rose->t2 / HZ;
			break;

		case ROSE_T3:
			val = sk->protinfo.rose->t3 / HZ;
			break;

		case ROSE_HOLDBACK:
			val = sk->protinfo.rose->hb / HZ;
			break;

		case ROSE_IDLE:
			val = sk->protinfo.rose->idle / (60 * HZ);
			break;

		case ROSE_QBITINCL:
			val = sk->protinfo.rose->qbitincl;
			break;

		default:
			return -ENOPROTOOPT;
	}