/*
* snull.c -- the Simple Network Utility
*
* Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
* Copyright (C) 2001 O'Reilly & Associates
*
* The source code in this file can be freely used, adapted,
* and redistributed in source or binary form, so long as an
* acknowledgment appears in derived source files. The citation
* should list that the code comes from the book "Linux Device
* Drivers" by Alessandro Rubini and Jonathan Corbet, published
* by O'Reilly & Associates. No warranty is attached;
* we cannot take responsibility for errors or fitness for use.
*
* $Id: snull.c,v 1.21 2004/11/05 02:36:03 rubini Exp $
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/kernel.h> /* printk() */
#include <linux/slab.h> /* kmalloc() */
#include <linux/errno.h> /* error codes */
#include <linux/types.h> /* size_t */
#include <linux/interrupt.h> /* mark_bh */
#include <linux/in.h>
#include <linux/netdevice.h> /* struct device, and other headers */
#include <linux/etherdevice.h> /* eth_type_trans */
#include <linux/ip.h> /* struct iphdr */
#include <linux/tcp.h> /* struct tcphdr */
#include <linux/skbuff.h>
#include "snull.h"
#include <linux/in6.h>
#include <asm/checksum.h>
MODULE_AUTHOR("Alessandro Rubini, Jonathan Corbet");
MODULE_LICENSE("Dual BSD/GPL");
/*
* Transmitter lockup simulation, normally disabled.
*/
static int lockup = 0;
module_param(lockup, int, 0);
static int timeout = SNULL_TIMEOUT;
module_param(timeout, int, 0);
/*
* Do we run in NAPI mode?
*/
static int use_napi = 0;
module_param(use_napi, int, 0);
/*
* A structure representing an in-flight packet.
*/
struct snull_packet {
struct snull_packet *next;
struct net_device *dev;
int datalen;
u8 data[ETH_DATA_LEN];
};
int pool_size = 8;
module_param(pool_size, int, 0);
/*
* This structure is private to each device. It is used to pass
* packets in and out, so there is place for a packet
*/
struct snull_priv {
struct net_device_stats stats;
int status;
struct snull_packet *ppool;
struct snull_packet *rx_queue; /* List of incoming packets */
int rx_int_enabled;
int tx_packetlen;
u8 *tx_packetdata;
struct sk_buff *skb;
spinlock_t lock;
};
static void snull_tx_timeout(struct net_device *dev);
static void (*snull_interrupt)(int, void *, struct pt_regs *);
/*
* Set up a device's packet pool.
*/
void snull_setup_pool(struct net_device *dev)
{
struct snull_priv *priv = netdev_priv(dev);
int i;
struct snull_packet *pkt;
priv->ppool = NULL;
for (i = 0; i < pool_size; i++) {
pkt = kmalloc (sizeof (struct snull_packet), GFP_KERNEL);
if (pkt == NULL) {
printk (KERN_NOTICE "Ran out of memory allocating packet pool\n");
return;
}
pkt->dev = dev;
pkt->next = priv->ppool;
priv->ppool = pkt;
}
}
void snull_teardown_pool(struct net_device *dev)
{
struct snull_priv *priv = netdev_priv(dev);
struct snull_packet *pkt;
while ((pkt = priv->ppool)) {
priv->ppool = pkt->next;
kfree (pkt);
/* FIXME - in-flight packets ? */
}
}
/*
* Buffer/pool management.
*/
struct snull_packet *snull_get_tx_buffer(struct net_device *dev)
{
struct snull_priv *priv = netdev_priv(dev);
unsigned long flags;
struct snull_packet *pkt;
spin_lock_irqsave(&priv->lock, flags);
pkt = priv->ppool;
priv->ppool = pkt->next;
if (priv->ppool == NULL) {
printk (KERN_INFO "Pool empty\n");
netif_stop_queue(dev);
}
spin_unlock_irqrestore(&priv->lock, flags);
return pkt;
}
void snull_release_buffer(struct snull_packet *pkt)
{
unsigned long flags;
struct snull_priv *priv = netdev_priv(pkt->dev);
spin_lock_irqsave(&priv->lock, flags);
pkt->next = priv->ppool;
priv->ppool = pkt;
spin_unlock_irqrestore(&priv->lock, flags);
if (netif_queue_stopped(pkt->dev) && pkt->next == NULL)
netif_wake_queue(pkt->dev);
}
void snull_enqueue_buf(struct net_device *dev, struct snull_packet *pkt)
{
unsigned long flags;
struct snull_priv *priv = netdev_priv(dev);
spin_lock_irqsave(&priv->lock, flags);
pkt->next = priv->rx_queue; /* FIXME - misorders packets */
priv->rx_queue = pkt;
spin_unlock_irqrestore(&priv->lock, flags);
}
struct snull_packet *snull_dequeue_buf(struct net_device *dev)
{
struct snull_priv *priv = netdev_priv(dev);
struct snull_packet *pkt;
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
pkt = priv->rx_queue;
if (pkt != NULL)
priv->rx_queue = pkt->next;
spin_unlock_irqrestore(&priv->lock, flags);
return pkt;
}
/*
* Enable and disable receive interrupts.
*/
static void snull_rx_ints(struct net_device *dev, int enable)
{
struct snull_priv *priv = netdev_priv(dev);
priv->rx_int_enabled = enable;
}
/*
* Open and close
*/
int snull_open(struct net_device *dev)
{
/* request_region(), request_irq(), .... (like fops->open) */
/*
* Assign the hardware address of the board: use "\0SNULx", where
* x is 0 or 1. The first byte is '\0' to avoid being a multicast
* address (the first byte of multicast addrs is odd).
*/
memcpy(dev->dev_addr, "\0SNUL0", ETH_ALEN);
if (dev == snull_devs[1])
dev->dev_addr[ETH_ALEN-1]++; /* \0SNUL1 */
netif_start_queue(dev);
return 0;
}
int snull_release(struct net_device *dev)
{
/* release ports, irq and such -- like fops->close */
netif_stop_queue(dev); /* can't transmit any more */
return 0;
}
/*
* Configuration changes (passed on by ifconfig)
*/
int snull_config(struct net_device *dev, struct ifmap *map)
{
if (dev->flags & IFF_UP) /* can't act on a running interface */
return -EBUSY;
/* Don't allow changing the I/O address */
if (map->base_addr != dev->base_addr) {
printk(KERN_WARNING "snull: Can't change I/O address\n");
return -EOPNOTSUPP;
}
/* Allow changing the IRQ */
if (map->irq != dev->irq) {
dev->irq = map->irq;
/* request_irq() is delayed to open-time */
}
/* ignore other fields */
return 0;
}
/*
* Receive a packet: retrieve, encapsulate and pass over to upper levels
*/
void snull_rx(struct net_device *dev, struct snull_packet *pkt)
{
struct sk_buff *skb;
struct snull_priv *priv = netdev_priv(dev);
/*
* The packet has been retrieved from the transmission
* medium. Build an skb around it, so upper layers can handle it
*/
skb = dev_alloc_skb(pkt->datalen + 2);
if (!skb) {
if (printk_ratelimit())
printk(KERN_NOTICE "snull rx: low on mem - packet dropped\n");
priv->stats.rx_dropped++;
goto out;
}
skb_reserve(skb, 2); /* align IP on 16B boundary */
memcpy(skb_put(skb, pkt->datalen), pkt->data, pkt->datalen);
/* Write metadata, and then pass to the receive level */
skb->dev = dev;
skb->protocol = eth_type_trans(skb, dev);
skb->ip_summed = CHECKSUM_UNNECESSARY; /* don't check it */
priv->stats.rx_packets++;
priv->stats.rx_bytes += pkt->datalen;
netif_rx(skb);
out:
return;
}
/*
* The poll implementation.
*/
static int snull_poll(struct net_device *dev, int *budget)
{
int npackets = 0, quota = min(dev->quota, *budget);
struct sk_buff *skb;
struct snull_priv *priv = netdev_priv(dev);
struct snull_packet *pkt;
while (npackets < quota && priv->rx_queue) {
pkt = snull_dequeue_buf(dev);
skb = dev_alloc_skb(pkt->datalen + 2);
if (! skb) {
if (printk_ratelimit())
printk(KERN_NOTICE "snull: packet dropped\n");
priv->stats.rx_dropped++;
snull_release_buffer(pkt);
continue;
}
skb_reserve(skb, 2); /* align IP on 16B boundary */
memcpy(skb_put(skb, pkt->datalen), pkt->data, pkt->datalen);
skb->dev = dev;
skb->protocol = eth_type_trans(skb, dev);
skb->ip_summed = CHECKSUM_UNNECESSARY; /* don't check it */
netif_receive_skb(skb);
/* Maintain stats */
npackets++;
priv->stats.rx_packets++;
priv->stats.rx_bytes += pkt->datalen;
snull_release_buffer(pkt);
}
/* If we processed all packets, we're done; tell the kernel and reenable ints */
*budget -= npackets;
dev->quota -= npacke
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LINUX设备驱动程序第三版配套源码
共97个文件
c:47个
makefile:18个
h:9个
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Linux设备驱动程序第三版源码.rar (97个子文件)
LINUX设备驱动程序第三版配套源码
sculld
mmap.c 3KB
main.c 15KB
Makefile 739B
sculld_load 755B
sculld.h 4KB
sculld_unload 182B
shortprint
shortprint_unload 174B
shortprint.h 1KB
shortprint.c 14KB
shortprint_load 624B
Makefile 507B
scullc
scullc.h 3KB
scullc_unload 182B
mmap.c 3KB
main.c 14KB
Makefile 732B
scullc_load 755B
scullv
scullv_unload 182B
mmap.c 3KB
main.c 14KB
scullv_load 755B
scullv.h 3KB
Makefile 739B
misc-modules
hello.c 463B
kdataalign.c 2KB
silly.c 6KB
seq.c 2KB
hellop.c 1KB
jiq.c 6KB
jit.c 7KB
kdatasize.c 1KB
complete.c 2KB
sleepy.c 2KB
Makefile 987B
faulty.c 2KB
simple
simple_unload 170B
simple_load 737B
simple.c 6KB
Makefile 696B
usb
usb-skeleton.c 9KB
Makefile 212B
lddbus
lddbus.c 4KB
Makefile 710B
scullp
mmap.c 3KB
scullp_unload 182B
main.c 14KB
scullp.h 3KB
scullp_load 755B
Makefile 739B
include
lddbus.h 855B
LICENSE 1KB
skull
skull_clean.c 336B
Makefile 5B
skull_init.c 6KB
sbull
sbull_load 1KB
sbull_unload 184B
sbull.h 2KB
sbull.c 10KB
Makefile 682B
pci
pci_skel.c 1KB
Makefile 208B
snull
snull.c 18KB
snull.h 1KB
snull_load 171B
Makefile 682B
snull_unload 77B
Makefile 289B
short
short_unload 237B
short_load 2KB
short.c 17KB
Makefile 681B
scull
scull.h 5KB
scull_load 2KB
main.c 16KB
scull.init 3KB
scull_unload 335B
pipe.c 11KB
access.c 11KB
Makefile 752B
tty
tiny_serial.c 6KB
Makefile 699B
tiny_tty.c 15KB
misc-progs
datasize.c 1KB
setlevel.c 2KB
inp.c 3KB
nbtest.c 1KB
setconsole.c 1KB
asynctest.c 1KB
outp.c 4KB
dataalign.c 2KB
mapcmp.c 2KB
Makefile 297B
load50.c 925B
polltest.c 1KB
mapper.c 2KB
netifdebug.c 2KB
gdbline 417B
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