Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 2611 insertions, 0 deletions

diff --git a/net/wanrouter/af_wanpipe.c b/net/wanrouter/af_wanpipe.c
new file mode 100644
index 00000000000..d93b19faaab
--- /dev/null
+++ b/net/wanrouter/af_wanpipe.c
@@ -0,0 +1,2611 @@
+/*****************************************************************************
+* af_wanpipe.c	WANPIPE(tm) Secure Socket Layer.
+*
+* Author:	Nenad Corbic	<ncorbic@sangoma.com>
+*
+* Copyright:	(c) 2000 Sangoma Technologies Inc.
+*
+*		This program 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.
+* ============================================================================
+* Due Credit:
+*               Wanpipe socket layer is based on Packet and 
+*               the X25 socket layers. The above sockets were 
+*               used for the specific use of Sangoma Technoloiges 
+*               API programs. 
+*               Packet socket Authors: Ross Biro, Fred N. van Kempen and 
+*                                      Alan Cox.
+*               X25 socket Author: Jonathan Naylor.
+* ============================================================================
+* Mar 15, 2002  Arnaldo C. Melo  o Use wp_sk()->num, as it isnt anymore in sock
+* Apr 25, 2000  Nenad Corbic     o Added the ability to send zero length packets.
+* Mar 13, 2000  Nenad Corbic	 o Added a tx buffer check via ioctl call.
+* Mar 06, 2000  Nenad Corbic     o Fixed the corrupt sock lcn problem.
+*                                  Server and client applicaton can run
+*                                  simultaneously without conflicts.
+* Feb 29, 2000  Nenad Corbic     o Added support for PVC protocols, such as
+*                                  CHDLC, Frame Relay and HDLC API.
+* Jan 17, 2000 	Nenad Corbic	 o Initial version, based on AF_PACKET socket.
+*			           X25API support only. 
+*
+******************************************************************************/
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/fcntl.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/poll.h>
+#include <linux/wireless.h>
+#include <linux/kmod.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/wanpipe.h>
+#include <linux/if_wanpipe.h>
+#include <linux/pkt_sched.h>
+#include <linux/tcp.h>
+#include <linux/if_wanpipe_common.h>
+#include <linux/sdla_x25.h>
+
+#ifdef CONFIG_INET
+#include <net/inet_common.h>
+#endif
+
+#define SLOW_BACKOFF 0.1*HZ
+#define FAST_BACKOFF 0.01*HZ
+
+//#define PRINT_DEBUG
+#ifdef PRINT_DEBUG
+	#define DBG_PRINTK(format, a...) printk(format, ## a)
+#else
+	#define DBG_PRINTK(format, a...)
+#endif      
+
+
+/* SECURE SOCKET IMPLEMENTATION 
+ * 
+ *   TRANSMIT:
+ *
+ *      When the user sends a packet via send() system call
+ *      the wanpipe_sendmsg() function is executed.  
+ *      
+ *      Each packet is enqueud into sk->sk_write_queue transmit
+ *      queue. When the packet is enqueued, a delayed transmit
+ *      timer is triggerd which acts as a Bottom Half hander. 
+ *
+ *      wanpipe_delay_transmit() function (BH), dequeues packets
+ *      from the sk->sk_write_queue transmit queue and sends it 
+ *      to the deriver via dev->hard_start_xmit(skb, dev) function.  
+ *      Note, this function is actual a function pointer of if_send()
+ *      routine in the wanpipe driver.
+ *
+ *      X25API GUARANTEED DELIVERY:
+ *
+ *         In order to provide 100% guaranteed packet delivery, 
+ *         an atomic 'packet_sent' counter is implemented.  Counter 
+ *         is incremented for each packet enqueued 
+ *         into sk->sk_write_queue.  Counter is decremented each
+ *         time wanpipe_delayed_transmit() function successfuly 
+ *         passes the packet to the driver. Before each send(), a poll
+ *         routine checks the sock resources The maximum value of
+ *         packet sent counter is 1, thus if one packet is queued, the
+ *         application will block until that packet is passed to the
+ *         driver.
+ *
+ *   RECEIVE:
+ *
+ *      Wanpipe device drivers call the socket bottom half
+ *      function, wanpipe_rcv() to queue the incoming packets
+ *      into an AF_WANPIPE socket queue.  Based on wanpipe_rcv()
+ *      return code, the driver knows whether the packet was
+ *      successfully queued.  If the socket queue is full, 
+ *      protocol flow control is used by the driver, if any, 
+ *      to slow down the traffic until the sock queue is free.
+ *
+ *      Every time a packet arrives into a socket queue the 
+ *      socket wakes up processes which are waiting to receive
+ *      data.
+ *
+ *      If the socket queue is full, the driver sets a block
+ *      bit which signals the socket to kick the wanpipe driver
+ *      bottom half hander when the socket queue is partialy
+ *      empty. wanpipe_recvmsg() function performs this action.
+ * 
+ *      In case of x25api, packets will never be dropped, since
+ *      flow control is available. 
+ *      
+ *      In case of streaming protocols like CHDLC, packets will 
+ *      be dropped but the statistics will be generated. 
+ */
+
+
+/* The code below is used to test memory leaks. It prints out
+ * a message every time kmalloc and kfree system calls get executed.
+ * If the calls match there is no leak :)
+ */
+
+/***********FOR DEBUGGING PURPOSES*********************************************
+#define KMEM_SAFETYZONE 8
+
+static void * dbg_kmalloc(unsigned int size, int prio, int line) {
+	void * v = kmalloc(size,prio);
+	printk(KERN_INFO "line %d  kmalloc(%d,%d) = %p\n",line,size,prio,v);
+	return v;
+}
+static void dbg_kfree(void * v, int line) {
+	printk(KERN_INFO "line %d  kfree(%p)\n",line,v);
+	kfree(v);
+}
+
+#define kmalloc(x,y) dbg_kmalloc(x,y,__LINE__)
+#define kfree(x) dbg_kfree(x,__LINE__)
+******************************************************************************/
+
+
+/* List of all wanpipe sockets. */
+HLIST_HEAD(wanpipe_sklist);
+static DEFINE_RWLOCK(wanpipe_sklist_lock);
+
+atomic_t wanpipe_socks_nr;
+static unsigned long wanpipe_tx_critical;
+
+#if 0
+/* Private wanpipe socket structures. */
+struct wanpipe_opt
+{
+	void   *mbox;		/* Mail box  */
+	void   *card; 		/* Card bouded to */
+	struct net_device *dev;	/* Bounded device */
+	unsigned short lcn;	/* Binded LCN */
+	unsigned char  svc;	/* 0=pvc, 1=svc */
+	unsigned char  timer;   /* flag for delayed transmit*/	
+	struct timer_list tx_timer;
+	unsigned poll_cnt;
+	unsigned char force;	/* Used to force sock release */
+	atomic_t packet_sent;   
+};
+#endif
+
+static int sk_count;
+extern struct proto_ops wanpipe_ops;
+static unsigned long find_free_critical;
+
+static void wanpipe_unlink_driver(struct sock *sk);
+static void wanpipe_link_driver(struct net_device *dev, struct sock *sk);
+static void wanpipe_wakeup_driver(struct sock *sk);
+static int execute_command(struct sock *, unsigned char, unsigned int);
+static int check_dev(struct net_device *dev, sdla_t *card);
+struct net_device *wanpipe_find_free_dev(sdla_t *card);
+static void wanpipe_unlink_card (struct sock *);
+static int wanpipe_link_card (struct sock *);
+static struct sock *wanpipe_make_new(struct sock *);
+static struct sock *wanpipe_alloc_socket(void);
+static inline int get_atomic_device(struct net_device *dev);
+static int wanpipe_exec_cmd(struct sock *, int, unsigned int);
+static int get_ioctl_cmd (struct sock *, void *);
+static int set_ioctl_cmd (struct sock *, void *);
+static void release_device(struct net_device *dev);
+static void wanpipe_kill_sock_timer (unsigned long data);
+static void wanpipe_kill_sock_irq (struct sock *);
+static void wanpipe_kill_sock_accept (struct sock *);
+static int wanpipe_do_bind(struct sock *sk, struct net_device *dev,
+			   int protocol);
+struct sock * get_newsk_from_skb (struct sk_buff *);
+static int wanpipe_debug (struct sock *, void *);
+static void wanpipe_delayed_transmit (unsigned long data);
+static void release_driver(struct sock *);
+static void start_cleanup_timer (struct sock *);
+static void check_write_queue(struct sock *);
+static int check_driver_busy (struct sock *);
+
+/*============================================================
+ * wanpipe_rcv
+ *
+ *	Wanpipe socket bottom half handler.  This function
+ *      is called by the WANPIPE device drivers to queue a
+ *      incoming packet into the socket receive queue. 
+ *      Once the packet is queued, all processes waiting to 
+ *      read are woken up.
+ *
+ *      During socket bind, this function is bounded into
+ *      WANPIPE driver private.
+ *===========================================================*/
+
+static int wanpipe_rcv(struct sk_buff *skb, struct net_device *dev,
+		       struct sock *sk)
+{
+	struct wan_sockaddr_ll *sll = (struct wan_sockaddr_ll*)skb->cb;
+	wanpipe_common_t *chan = dev->priv;
+	/*
+	 *	When we registered the protocol we saved the socket in the data
+	 *	field for just this event.
+	 */
+
+	skb->dev = dev;
+
+	sll->sll_family = AF_WANPIPE;
+	sll->sll_hatype = dev->type;
+	sll->sll_protocol = skb->protocol;
+	sll->sll_pkttype = skb->pkt_type;
+	sll->sll_ifindex = dev->ifindex;
+	sll->sll_halen = 0;
+
+	if (dev->hard_header_parse)
+		sll->sll_halen = dev->hard_header_parse(skb, sll->sll_addr);
+
+	/* 
+	 * WAN_PACKET_DATA : Data which should be passed up the receive queue.
+         * WAN_PACKET_ASYC : Asynchronous data like place call, which should
+         *                   be passed up the listening sock.
+         * WAN_PACKET_ERR  : Asynchronous data like clear call or restart 
+         *                   which should go into an error queue.
+         */
+	switch (skb->pkt_type){
+
+		case WAN_PACKET_DATA:
+			if (sock_queue_rcv_skb(sk,skb)<0){
+				return -ENOMEM;
+			}
+			break;
+		case WAN_PACKET_CMD:
+			sk->sk_state = chan->state;
+			/* Bug fix: update Mar6. 
+                         * Do not set the sock lcn number here, since
+         		 * cmd is not guaranteed to be executed on the
+                         * board, thus Lcn could be wrong */
+			sk->sk_data_ready(sk, skb->len);
+			kfree_skb(skb);
+			break;
+		case WAN_PACKET_ERR:
+			sk->sk_state = chan->state;
+			if (sock_queue_err_skb(sk,skb)<0){
+				return -ENOMEM;
+			}
+			break;
+		default:
+			printk(KERN_INFO "wansock: BH Illegal Packet Type Dropping\n");
+			kfree_skb(skb); 
+			break;
+	}
+
+//??????????????????????
+//	if (sk->sk_state == WANSOCK_DISCONNECTED){
+//		if (sk->sk_zapped) {
+//			//printk(KERN_INFO "wansock: Disconnected, killing early\n");
+//			wanpipe_unlink_driver(sk);
+//			sk->sk_bound_dev_if = 0;
+//		}
+//	}
+
+	return 0;
+}
+
+/*============================================================
+ * wanpipe_listen_rcv
+ *
+ *	Wanpipe LISTEN socket bottom half handler.  This function
+ *      is called by the WANPIPE device drivers to queue an
+ *      incoming call into the socket listening queue. 
+ *      Once the packet is queued, the waiting accept() process 
+ *      is woken up.
+ *
+ *      During socket bind, this function is bounded into
+ *      WANPIPE driver private. 
+ * 
+ *      IMPORTANT NOTE:
+ *          The accept call() is waiting for an skb packet
+ *          which contains a pointer to a device structure.
+ *
+ *          When we do a bind to a device structre, we 
+ *          bind a newly created socket into "chan->sk".  Thus, 
+ *          when accept receives the skb packet, it will know 
+ *          from which dev it came form, and in turn it will know
+ *          the address of the new sock.
+ *
+ *  	NOTE: This function gets called from driver ISR.
+ *===========================================================*/
+
+static int wanpipe_listen_rcv (struct sk_buff *skb,  struct sock *sk)
+{
+	wanpipe_opt *wp = wp_sk(sk), *newwp;
+	struct wan_sockaddr_ll *sll = (struct wan_sockaddr_ll*)skb->cb;
+	struct sock *newsk;
+	struct net_device *dev; 
+	sdla_t *card;
+	mbox_cmd_t *mbox_ptr;
+	wanpipe_common_t *chan;
+
+	/* Find a free device, if none found, all svc's are busy 
+         */
+
+	card = (sdla_t*)wp->card;
+	if (!card){
+		printk(KERN_INFO "wansock: LISTEN ERROR, No Card\n");
+		return -ENODEV;
+	}
+	
+	dev = wanpipe_find_free_dev(card);
+	if (!dev){
+		printk(KERN_INFO "wansock: LISTEN ERROR, No Free Device\n");
+		return -ENODEV;
+	}
+
+	chan=dev->priv;	
+	chan->state = WANSOCK_CONNECTING;
+
+	/* Allocate a new sock, which accept will bind
+         * and pass up to the user 
+	 */
+	if ((newsk = wanpipe_make_new(sk)) == NULL){
+		release_device(dev);
+		return -ENOMEM;
+	}
+
+
+	/* Initialize the new sock structure 
+	 */
+	newsk->sk_bound_dev_if = dev->ifindex;
+	newwp = wp_sk(newsk);
+	newwp->card = wp->card;
+
+	/* Insert the sock into the main wanpipe
+         * sock list.
+         */
+	atomic_inc(&wanpipe_socks_nr);
+
+	/* Allocate and fill in the new Mail Box. Then
+         * bind the mail box to the sock. It will be 
+         * used by the ioctl call to read call information
+         * and to execute commands. 
+         */	
+	if ((mbox_ptr = kmalloc(sizeof(mbox_cmd_t), GFP_ATOMIC)) == NULL) {
+		wanpipe_kill_sock_irq (newsk);
+		release_device(dev);		
+		return -ENOMEM;
+	}
+	memset(mbox_ptr, 0, sizeof(mbox_cmd_t));
+	memcpy(mbox_ptr,skb->data,skb->len);
+
+	/* Register the lcn on which incoming call came
+         * from. Thus, if we have to clear it, we know
+         * which lcn to clear
+	 */ 
+
+	newwp->lcn = mbox_ptr->cmd.lcn;
+	newwp->mbox = (void *)mbox_ptr;
+
+	DBG_PRINTK(KERN_INFO "NEWSOCK : Device %s, bind to lcn %i\n",
+			dev->name,mbox_ptr->cmd.lcn);
+
+	chan->lcn = mbox_ptr->cmd.lcn;
+	card->u.x.svc_to_dev_map[(chan->lcn%MAX_X25_LCN)] = dev;
+
+	sock_reset_flag(newsk, SOCK_ZAPPED);
+	newwp->num = htons(X25_PROT);
+
+	if (wanpipe_do_bind(newsk, dev, newwp->num)) {
+		wanpipe_kill_sock_irq (newsk);
+		release_device(dev);
+		return -EINVAL;
+	}
+	newsk->sk_state = WANSOCK_CONNECTING;
+
+
+	/* Fill in the standard sock address info */
+
+	sll->sll_family = AF_WANPIPE;
+	sll->sll_hatype = dev->type;
+	sll->sll_protocol = skb->protocol;
+	sll->sll_pkttype = skb->pkt_type;
+	sll->sll_ifindex = dev->ifindex;
+	sll->sll_halen = 0;
+
+	skb->dev = dev;
+	sk->sk_ack_backlog++;
+
+	/* We must do this manually, since the sock_queue_rcv_skb()
+	 * function sets the skb->dev to NULL.  However, we use
+	 * the dev field in the accept function.*/ 
+	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 
+	    (unsigned)sk->sk_rcvbuf) {
+
+         	wanpipe_unlink_driver(newsk);
+		wanpipe_kill_sock_irq (newsk);
+		--sk->sk_ack_backlog;
+		return -ENOMEM;
+	}	
+
+	skb_set_owner_r(skb, sk);
+	skb_queue_tail(&sk->sk_receive_queue, skb);
+	sk->sk_data_ready(sk, skb->len);
+	
+	return 0;
+}
+
+
+
+/*============================================================
+ * wanpipe_make_new
+ *
+ *	Create a new sock, and allocate a wanpipe private
+ *      structure to it. Also, copy the important data
+ *      from the original sock to the new sock.
+ *
+ *      This function is used by wanpipe_listen_rcv() listen
+ *      bottom half handler.  A copy of the listening sock
+ *      is created using this function.
+ *
+ *===========================================================*/
+
+static struct sock *wanpipe_make_new(struct sock *osk)
+{
+	struct sock *sk;
+
+	if (osk->sk_type != SOCK_RAW)
+		return NULL;
+
+	if ((sk = wanpipe_alloc_socket()) == NULL)
+		return NULL;
+
+	sk->sk_type	= osk->sk_type;
+	sk->sk_socket	= osk->sk_socket;
+	sk->sk_priority	= osk->sk_priority;
+	sk->sk_protocol	= osk->sk_protocol;
+	wp_sk(sk)->num	= wp_sk(osk)->num;
+	sk->sk_rcvbuf	= osk->sk_rcvbuf;
+	sk->sk_sndbuf	= osk->sk_sndbuf;
+	sk->sk_state	= WANSOCK_CONNECTING;
+	sk->sk_sleep	= osk->sk_sleep;
+
+	if (sock_flag(osk, SOCK_DBG))
+		sock_set_flag(sk, SOCK_DBG);
+
+	return sk;
+}
+
+/* 
+ * FIXME: wanpipe_opt has to include a sock in its definition and stop using
+ * sk_protinfo, but this code is not even compilable now, so lets leave it for
+ * later.
+ */
+static struct proto wanpipe_proto = {
+	.name	  = "WANPIPE",
+	.owner	  = THIS_MODULE,
+	.obj_size = sizeof(struct sock),
+};
+
+/*============================================================
+ * wanpipe_make_new
+ *
+ *	Allocate memory for the a new sock, and sock
+ *      private data.  
+ *	
+ *	Increment the module use count.
+ *       	
+ *      This function is used by wanpipe_create() and 
+ *      wanpipe_make_new() functions. 
+ *
+ *===========================================================*/
+
+static struct sock *wanpipe_alloc_socket(void)
+{
+	struct sock *sk;
+	struct wanpipe_opt *wan_opt;
+
+	if ((sk = sk_alloc(PF_WANPIPE, GFP_ATOMIC, &wanpipe_proto, 1)) == NULL)
+		return NULL;
+
+	if ((wan_opt = kmalloc(sizeof(struct wanpipe_opt), GFP_ATOMIC)) == NULL) {
+		sk_free(sk);
+		return NULL;
+	}
+	memset(wan_opt, 0x00, sizeof(struct wanpipe_opt));
+
+	wp_sk(sk) = wan_opt;
+
+	/* Use timer to send data to the driver. This will act
+         * as a BH handler for sendmsg functions */
+	init_timer(&wan_opt->tx_timer);
+	wan_opt->tx_timer.data	   = (unsigned long)sk;
+	wan_opt->tx_timer.function = wanpipe_delayed_transmit;
+
+	sock_init_data(NULL, sk);
+	return sk;
+}
+
+
+/*============================================================
+ * wanpipe_sendmsg
+ *
+ *	This function implements a sendto() system call,
+ *      for AF_WANPIPE socket family. 
+ *      During socket bind() sk->sk_bound_dev_if is initialized
+ *      to a correct network device. This number is used
+ *      to find a network device to which the packet should
+ *      be passed to.
+ *
+ *      Each packet is queued into sk->sk_write_queue and 
+ *      delayed transmit bottom half handler is marked for 
+ *      execution.
+ *
+ *      A socket must be in WANSOCK_CONNECTED state before
+ *      a packet is queued into sk->sk_write_queue.
+ *===========================================================*/
+
+static int wanpipe_sendmsg(struct kiocb *iocb, struct socket *sock,
+			   struct msghdr *msg, int len)
+{
+	wanpipe_opt *wp;
+	struct sock *sk = sock->sk;
+	struct wan_sockaddr_ll *saddr=(struct wan_sockaddr_ll *)msg->msg_name;
+	struct sk_buff *skb;
+	struct net_device *dev;
+	unsigned short proto;
+	unsigned char *addr;
+	int ifindex, err, reserve = 0;
+
+	
+	if (!sock_flag(sk, SOCK_ZAPPED))
+		return -ENETDOWN;
+
+	if (sk->sk_state != WANSOCK_CONNECTED)
+		return -ENOTCONN;	
+
+	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT)) 
+		return(-EINVAL);
+
+	/* it was <=, now one can send
+         * zero length packets */
+	if (len < sizeof(x25api_hdr_t))
+		return -EINVAL;
+
+	wp = wp_sk(sk);
+
+	if (saddr == NULL) {
+		ifindex	= sk->sk_bound_dev_if;
+		proto	= wp->num;
+		addr	= NULL;
+
+	}else{
+		if (msg->msg_namelen < sizeof(struct wan_sockaddr_ll)){ 
+			return -EINVAL;
+		}
+
+		ifindex = sk->sk_bound_dev_if;
+		proto	= saddr->sll_protocol;
+		addr	= saddr->sll_addr;
+	}
+
+	dev = dev_get_by_index(ifindex);
+	if (dev == NULL){
+		printk(KERN_INFO "wansock: Send failed, dev index: %i\n",ifindex);
+		return -ENXIO;
+	}
+	dev_put(dev);
+	
+	if (sock->type == SOCK_RAW)
+		reserve = dev->hard_header_len;
+
+	if (len > dev->mtu+reserve){
+  		return -EMSGSIZE;
+	}
+
+	skb = sock_alloc_send_skb(sk, len + LL_RESERVED_SPACE(dev),
+				msg->msg_flags & MSG_DONTWAIT, &err);
+
+	if (skb==NULL){
+		goto out_unlock;
+	}
+		
+	skb_reserve(skb, LL_RESERVED_SPACE(dev));
+	skb->nh.raw = skb->data;
+
+	/* Returns -EFAULT on error */
+	err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
+	if (err){
+		goto out_free;
+	}
+
+	if (dev->hard_header) {
+		int res;
+		err = -EINVAL;
+		res = dev->hard_header(skb, dev, ntohs(proto), addr, NULL, len);
+		if (res<0){
+			goto out_free;
+		}
+	}
+
+	skb->protocol = proto;
+	skb->dev = dev;
+	skb->priority = sk->sk_priority;
+	skb->pkt_type = WAN_PACKET_DATA;
+
+	err = -ENETDOWN;
+	if (!(dev->flags & IFF_UP))
+		goto out_free;
+
+	if (atomic_read(&sk->sk_wmem_alloc) + skb->truesize >
+	    (unsigned int)sk->sk_sndbuf){
+		kfree_skb(skb);
+		return -ENOBUFS;
+	}
+
+	skb_queue_tail(&sk->sk_write_queue,skb);
+	atomic_inc(&wp->packet_sent);
+
+	if (!(test_and_set_bit(0, &wp->timer)))
+		mod_timer(&wp->tx_timer, jiffies + 1);
+	
+	return(len);
+
+out_free:
+	kfree_skb(skb);
+out_unlock:
+	return err;
+}
+
+/*============================================================
+ * wanpipe_delayed_tarnsmit
+ *
+ *	Transmit bottom half handler. It dequeues packets
+ *      from sk->sk_write_queue and passes them to the 
+ *      driver.  If the driver is busy, the packet is 
+ *      re-enqueued.  
+ *
+ *      Packet Sent counter is decremented on successful
+ *      transmission. 
+ *===========================================================*/
+
+
+static void wanpipe_delayed_transmit (unsigned long data)
+{
+	struct sock *sk=(struct sock *)data;
+	struct sk_buff *skb;
+	wanpipe_opt *wp = wp_sk(sk);
+	struct net_device *dev = wp->dev;
+	sdla_t *card = (sdla_t*)wp->card;
+
+	if (!card || !dev){
+		clear_bit(0, &wp->timer);
+		DBG_PRINTK(KERN_INFO "wansock: Transmit delay, no dev or card\n");
+		return;
+	}
+	
+	if (sk->sk_state != WANSOCK_CONNECTED || !sock_flag(sk, SOCK_ZAPPED)) {
+		clear_bit(0, &wp->timer);
+		DBG_PRINTK(KERN_INFO "wansock: Tx Timer, State not CONNECTED\n");
+		return;
+	}
+	
+	/* If driver is executing command, we must offload
+         * the board by not sending data. Otherwise a 
+         * pending command will never get a free buffer
+         * to execute */ 	
+	if (atomic_read(&card->u.x.command_busy)){
+		wp->tx_timer.expires = jiffies + SLOW_BACKOFF;
+		add_timer(&wp->tx_timer);
+		DBG_PRINTK(KERN_INFO "wansock: Tx Timer, command bys BACKOFF\n");
+		return;
+	}
+
+	
+	if (test_and_set_bit(0,&wanpipe_tx_critical)){
+		printk(KERN_INFO "WanSock: Tx timer critical %s\n",dev->name);
+		wp->tx_timer.expires = jiffies + SLOW_BACKOFF;
+		add_timer(&wp->tx_timer);
+		return;
+	}	
+	
+	/* Check for a packet in the fifo and send */
+	if ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL){
+
+		if (dev->hard_start_xmit(skb, dev) != 0){			
+
+			/* Driver failed to transmit, re-enqueue
+                         * the packet and retry again later */
+			skb_queue_head(&sk->sk_write_queue,skb);
+			clear_bit(0,&wanpipe_tx_critical);
+			return;
+		}else{
+
+			/* Packet Sent successful. Check for more packets
+                         * if more packets, re-trigger the transmit routine 
+                         * other wise exit
+                         */
+			atomic_dec(&wp->packet_sent);
+
+			if (skb_peek(&sk->sk_write_queue) == NULL) {
+				/* If there is nothing to send, kick
+				 * the poll routine, which will trigger
+				 * the application to send more data */
+				sk->sk_data_ready(sk, 0);
+				clear_bit(0, &wp->timer);
+			}else{
+				/* Reschedule as fast as possible */
+				wp->tx_timer.expires = jiffies + 1;
+				add_timer(&wp->tx_timer);
+			}
+		}
+	}
+	clear_bit(0,&wanpipe_tx_critical);
+}
+
+/*============================================================
+ * execute_command 
+ *
+ *	Execute x25api commands.  The atomic variable
+ *      chan->command is used to indicate to the driver that
+ *      command is pending for execution.  The acutal command
+ *      structure is placed into a sock mbox structure 
+ *      (wp_sk(sk)->mbox).
+ *
+ *      The sock private structure, mbox is
+ *      used as shared memory between sock and the driver.
+ *      Driver uses the sock mbox to execute the command
+ *      and return the result.  
+ *
+ *      For all command except PLACE CALL, the function
+ *      waits for the result.  PLACE CALL can be ether
+ *      blocking or nonblocking. The user sets this option
+ *      via ioctl call.
+ *===========================================================*/
+
+
+static int execute_command(struct sock *sk,  unsigned char cmd, unsigned int flags)
+{
+	wanpipe_opt *wp = wp_sk(sk);
+	struct net_device *dev;
+	wanpipe_common_t *chan=NULL;
+	int err=0;
+	DECLARE_WAITQUEUE(wait, current);
+	
+	dev = dev_get_by_index(sk->sk_bound_dev_if);
+	if (dev == NULL){
+		printk(KERN_INFO "wansock: Exec failed no dev %i\n",
+			sk->sk_bound_dev_if);
+		return -ENODEV;
+	}
+	dev_put(dev);
+
+	if ((chan=dev->priv) == NULL){
+		printk(KERN_INFO "wansock: Exec cmd failed no priv area\n");
+		return -ENODEV;
+	}
+
+	if (atomic_read(&chan->command)){
+		printk(KERN_INFO "wansock: ERROR: Command already running %x, %s\n",
+			atomic_read(&chan->command),dev->name);
+		return -EINVAL;
+	}
+
+	if (!wp->mbox) {
+		printk(KERN_INFO "wansock: In execute without MBOX\n");
+		return -EINVAL;
+	}
+
+	((mbox_cmd_t*)wp->mbox)->cmd.command = cmd;	
+	((mbox_cmd_t*)wp->mbox)->cmd.lcn     = wp->lcn;
+	((mbox_cmd_t*)wp->mbox)->cmd.result  = 0x7F;
+
+
+	if (flags & O_NONBLOCK){
+		cmd |= 0x80;
+		atomic_set(&chan->command, cmd);
+	}else{
+		atomic_set(&chan->command, cmd);
+	}
+
+	add_wait_queue(sk->sk_sleep,&wait);
+	current->state = TASK_INTERRUPTIBLE;
+	for (;;){
+		if (((mbox_cmd_t*)wp->mbox)->cmd.result != 0x7F) {
+			err = 0;
+			break;
+		}
+		if (signal_pending(current)) {
+			err = -ERESTARTSYS;
+			break;
+		}
+		schedule();
+	}
+	current->state = TASK_RUNNING;
+	remove_wait_queue(sk->sk_sleep,&wait);
+	
+	return err;
+}
+
+/*============================================================
+ * wanpipe_destroy_timer 
+ *
+ *	Used by wanpipe_release, to delay release of
+ *      the socket.
+ *===========================================================*/
+
+static void wanpipe_destroy_timer(unsigned long data)
+{
+	struct sock *sk=(struct sock *)data;
+	wanpipe_opt *wp = wp_sk(sk);
+
+	if ((!atomic_read(&sk->sk_wmem_alloc) &&
+	     !atomic_read(&sk->sk_rmem_alloc)) ||
+	    (++wp->force == 5)) {
+
+		if (atomic_read(&sk->sk_wmem_alloc) ||
+		    atomic_read(&sk->sk_rmem_alloc))
+			printk(KERN_INFO "wansock: Warning, Packet Discarded due to sock shutdown!\n");
+
+		kfree(wp);
+		wp_sk(sk) = NULL;
+		
+		if (atomic_read(&sk->sk_refcnt) != 1) {
+			atomic_set(&sk->sk_refcnt, 1);
+			DBG_PRINTK(KERN_INFO "wansock: Error, wrong reference count: %i ! :delay.\n",
+					atomic_read(&sk->sk_refcnt));
+		}
+		sock_put(sk);
+		atomic_dec(&wanpipe_socks_nr);
+		return;
+	}
+
+	sk->sk_timer.expires = jiffies + 5 * HZ;
+	add_timer(&sk->sk_timer);
+	printk(KERN_INFO "wansock: packet sk destroy delayed\n");
+}
+
+/*============================================================
+ * wanpipe_unlink_driver
+ *
+ * 	When the socket is released, this function is 
+ *      used to remove links that bind the sock and the
+ *      driver together.  
+ *===========================================================*/
+static void wanpipe_unlink_driver (struct sock *sk)
+{
+	struct net_device *dev;
+	wanpipe_common_t *chan=NULL;
+
+	sock_reset_flag(sk, SOCK_ZAPPED);
+	sk->sk_state = WANSOCK_DISCONNECTED;
+	wp_sk(sk)->dev = NULL;
+
+	dev = dev_get_by_index(sk->sk_bound_dev_if);
+	if (!dev){
+		printk(KERN_INFO "wansock: No dev on release\n");
+		return;
+	}			
+	dev_put(dev);
+
+	if ((chan = dev->priv) == NULL){
+		printk(KERN_INFO "wansock: No Priv Area on release\n");
+		return;
+	}
+
+	set_bit(0,&chan->common_critical);
+	chan->sk=NULL;
+	chan->func=NULL;
+	chan->mbox=NULL;
+	chan->tx_timer=NULL;
+	clear_bit(0,&chan->common_critical);
+	release_device(dev);
+	
+	return;
+}
+
+/*============================================================
+ * wanpipe_link_driver
+ *
+ * 	Upon successful bind(), sock is linked to a driver
+ *      by binding in the wanpipe_rcv() bottom half handler
+ *      to the driver function pointer, as well as sock and
+ *      sock mailbox addresses.  This way driver can pass
+ *      data up the socket.
+ *===========================================================*/
+
+static void wanpipe_link_driver(struct net_device *dev, struct sock *sk)
+{
+	wanpipe_opt *wp = wp_sk(sk);
+	wanpipe_common_t *chan = dev->priv;
+	if (!chan)
+		return;
+	set_bit(0,&chan->common_critical);
+	chan->sk=sk;
+	chan->func=wanpipe_rcv;
+	chan->mbox = wp->mbox;
+	chan->tx_timer = &wp->tx_timer;
+	wp->dev = dev;
+	sock_set_flag(sk, SOCK_ZAPPED);
+	clear_bit(0,&chan->common_critical);
+}
+
+
+/*============================================================
+ * release_device
+ *
+ *   	During sock release, clear a critical bit, which 
+ *      marks the device a being taken.
+ *===========================================================*/
+
+
+static void release_device(struct net_device *dev)
+{
+	wanpipe_common_t *chan=dev->priv;
+	clear_bit(0,(void*)&chan->rw_bind);
+}
+
+/*============================================================
+ * wanpipe_release
+ *
+ *	Close a PACKET socket. This is fairly simple. We 
+ *      immediately go to 'closed' state and remove our 
+ *      protocol entry in the device list.
+ *===========================================================*/
+
+static int wanpipe_release(struct socket *sock)
+{
+	wanpipe_opt *wp;
+	struct sock *sk = sock->sk;
+	
+	if (!sk)
+		return 0;
+
+	wp = wp_sk(sk);
+	check_write_queue(sk);
+
+	/* Kill the tx timer, if we don't kill it now, the timer
+         * will run after we kill the sock.  Timer code will 
+         * try to access the sock which has been killed and cause
+         * kernel panic */
+
+	del_timer(&wp->tx_timer);
+
+	/*
+	 *	Unhook packet receive handler.
+	 */
+
+	if (wp->num == htons(X25_PROT) &&
+	    sk->sk_state != WANSOCK_DISCONNECTED && sock_flag(sk, SOCK_ZAPPED)) {
+		struct net_device *dev = dev_get_by_index(sk->sk_bound_dev_if);
+		wanpipe_common_t *chan;
+		if (dev){
+			chan=dev->priv;
+			atomic_set(&chan->disconnect,1);
+			DBG_PRINTK(KERN_INFO "wansock: Sending Clear Indication %i\n",
+					sk->sk_state);
+			dev_put(dev);
+		}	
+	}
+
+	set_bit(1,&wanpipe_tx_critical);
+	write_lock(&wanpipe_sklist_lock);
+	sk_del_node_init(sk);
+	write_unlock(&wanpipe_sklist_lock);
+	clear_bit(1,&wanpipe_tx_critical);
+
+
+	
+	release_driver(sk);
+
+	
+	/*
+	 *	Now the socket is dead. No more input will appear.
+	 */
+
+	sk->sk_state_change(sk);	/* It is useless. Just for sanity. */
+
+	sock->sk = NULL;
+	sk->sk_socket = NULL;
+	sock_set_flag(sk, SOCK_DEAD);
+
+	/* Purge queues */
+	skb_queue_purge(&sk->sk_receive_queue);
+	skb_queue_purge(&sk->sk_write_queue);
+	skb_queue_purge(&sk->sk_error_queue);
+
+	if (atomic_read(&sk->sk_rmem_alloc) ||
+	    atomic_read(&sk->sk_wmem_alloc)) {
+		del_timer(&sk->sk_timer);
+		printk(KERN_INFO "wansock: Killing in Timer R %i , W %i\n",
+			atomic_read(&sk->sk_rmem_alloc),
+			atomic_read(&sk->sk_wmem_alloc));
+		sk->sk_timer.data	= (unsigned long)sk;
+		sk->sk_timer.expires	= jiffies + HZ;
+		sk->sk_timer.function	= wanpipe_destroy_timer;
+		add_timer(&sk->sk_timer);
+		return 0;
+	}
+
+	kfree(wp);
+	wp_sk(sk) = NULL;
+
+	if (atomic_read(&sk->sk_refcnt) != 1) {
+		DBG_PRINTK(KERN_INFO "wansock: Error, wrong reference count: %i !:release.\n",
+					atomic_read(&sk->sk_refcnt));
+		atomic_set(&sk->sk_refcnt, 1);
+	}
+	sock_put(sk);
+	atomic_dec(&wanpipe_socks_nr);
+	return 0;
+}
+
+/*============================================================
+ * check_write_queue
+ *
+ *  	During sock shutdown, if the sock state is 
+ *      WANSOCK_CONNECTED and there is transmit data 
+ *      pending. Wait until data is released 
+ *      before proceeding.
+ *===========================================================*/
+
+static void check_write_queue(struct sock *sk)
+{
+
+	if (sk->sk_state != WANSOCK_CONNECTED)
+		return;
+
+	if (!atomic_read(&sk->sk_wmem_alloc))
+		return;
+
+	printk(KERN_INFO "wansock: MAJOR ERROR, Data lost on sock release !!!\n");
+
+}
+
+/*============================================================
+ * release_driver
+ *
+ *	This function is called during sock shutdown, to 
+ *      release any resources and links that bind the sock
+ *      to the driver.  It also changes the state of the
+ *      sock to WANSOCK_DISCONNECTED
+ *===========================================================*/
+
+static void release_driver(struct sock *sk)
+{
+	wanpipe_opt *wp;
+	struct sk_buff *skb=NULL;
+	struct sock *deadsk=NULL;
+
+	if (sk->sk_state == WANSOCK_LISTEN ||
+	    sk->sk_state == WANSOCK_BIND_LISTEN) {
+		while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+			if ((deadsk = get_newsk_from_skb(skb))){
+				DBG_PRINTK (KERN_INFO "wansock: RELEASE: FOUND DEAD SOCK\n");
+				sock_set_flag(deadsk, SOCK_DEAD);
+				start_cleanup_timer(deadsk);
+			}
+			kfree_skb(skb);
+		}
+		if (sock_flag(sk, SOCK_ZAPPED))
+			wanpipe_unlink_card(sk);
+	}else{
+		if (sock_flag(sk, SOCK_ZAPPED))
+			wanpipe_unlink_driver(sk);
+	}
+	sk->sk_state	    = WANSOCK_DISCONNECTED;
+	sk->sk_bound_dev_if = 0;
+	sock_reset_flag(sk, SOCK_ZAPPED);
+	wp = wp_sk(sk);
+