hi ravi,
your net driver doesn't fit into a proper net driver reasons being:
1)what is the char driver doing in a net driver
2)dev->priv is being typecasted to test_struct and assigned to
test_struct c; which itself has net_device variable:
Please remember that dev->priv is used for holding private data like the
statistics etc.,
Please go thru skeleton of a sample net driver in
/usr/src/linux-2.4.x/drivers/net/pci-skeleton.c
/usr/src/linux-2.4.x/drivers/net/loopback.c
Hope this helps
Regards
Syed
On Mon, 2004-06-28 at 18:48, Ravi Kumar wrote:
> Hi,
> I wrote a module to create dummy ethernet device, the intention is to
> add it to a bridge and transmit modified packets. I get ethernet device
> created but its xmit function is not called when the bridge receives a
> packet.
>
> I feel I have missed some information to register netdevice.
>
> To add to bridge I did the following:
> brctl addbr br0
> brctl addif bro eth0
> brctl addif br0 firsteth0
> ifconfig etho 0.0.0.0
> ifconfig bro 172.16.2.100 up
>
> When I try to add IP address to firsteth0, I get a kernel panic!!
> Can we give IP to dummy ethernet device?
>
> Please help, I am given little time to complete this :( I am attaching
> the code for the dummy ethernet device.
> -Ravi
> ----
>
> #ifndef __KERNEL__
> # define __KERNEL__
> #endif
>
> #ifndef MODULE
> # define MODULE
> #endif
>
> #define DEVNAME "firsteth"
>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <linux/fs.h>
> #include <linux/slab.h>
>
> #include <linux/netdevice.h>
> #include <linux/if_ether.h>
> #include <linux/rtnetlink.h>
> #include <linux/if_arp.h>
>
> /* netfilters related */
> #include <linux/netfilter.h>
> #include <linux/netfilter_ipv4.h>
>
> #include <linux/in.h>
> #include <linux/udp.h>
> #include <net/ip.h>
>
> int test_open(struct inode *,struct file *);
> int test_release(struct inode *,struct file*);
>
>
> struct test_struct{
> struct net_device *dev;
> char name[IFNAMSIZ];
>
> };
>
> struct file_operations test_fop={
> llseek: NULL,
> read: NULL,
> write: NULL,
> ioctl: NULL,
> open: test_open,
> release: test_release,
> };
>
>
> struct test_struct pTestStruct;
>
>
> static int testdev_xmit(struct sk_buff *skb, struct net_device *dev)
> {
> struct iphdr *oldiph;
> unsigned char tos=0;
> unsigned short df =0;
> unsigned char ttl;
>
> printk(KERN_INFO " In xmit function\n");
> oldiph = (skb->protocol==htons(ETH_P_IP))
> ? (struct iphdr*)(skb->data+ETH_HLEN)
> : NULL;
>
> tos = oldiph->tos;
> df = oldiph->frag_off;
> ttl = oldiph->ttl;
> printk(KERN_INFO"src IP: %x dst IP: %x , protocol %d \n",ntohl(oldiph->saddr), ntohl(oldiph->daddr),oldiph->protocol);
>
> return 0;
> }
>
> int test_open(struct inode *inode, struct file *filep)
> {
> MOD_INC_USE_COUNT;
> return 0;
> }
>
> int test_release(struct inode *inode, struct file *filep)
> {
> MOD_DEC_USE_COUNT;
> return 0;
> }
>
> int testdev_open(struct net_device *dev)
> {
> MOD_INC_USE_COUNT;
> return 0;
> }
>
> int testdev_close(struct net_device *dev)
> {
> unregister_netdev(dev);
> MOD_DEC_USE_COUNT;
> return 0;
> }
> //t test_ioctl(struct inode *inode,
> static int test_init_dev(struct net_device *dev)
> {
> struct test_struct *c;
>
> printk(KERN_INFO "in test_init_dev\n");
>
> c = (struct test_struct *)dev->priv;
> if(!c)
> return -ENODEV;
>
> memset(c,0,sizeof(struct test_struct));
> c->dev = dev;
>
> // ether_setup(dev);
> dev->open = testdev_open;
> dev->stop = testdev_close;
> dev->hard_start_xmit = testdev_xmit;
> dev->mtu = ETH_DATA_LEN - sizeof(struct udphdr) - sizeof(struct iphdr) ;
> dev_init_buffers(dev);
>
> printk(KERN_INFO "completed test_init_dev\n");
> return 0;
> }
>
>
> int init_module(void)
> {
> int result,i;
> struct net_device *tempDev;
> struct test_struct *temp_struct;
> char devname[25]; // Remove the hardcode
>
>
> for(i=0;i<99;i++)
> {
> sprintf(devname,"firseth%d",i);
> if(__dev_get_by_name(devname) == NULL)
> break;
> }
> if(i==100)
> return -ENFILE;
> printk(KERN_INFO "********MACOUDP TUNNEL******\n");
>
> temp_struct = (struct test_struct *)kmalloc(sizeof(struct test_struct),GFP_KERNEL);
> if(!temp_struct)
> {
> printk(KERN_ERR "error in allocating memory\n");
> return -ENOMEM;
> }
> result = register_chrdev(244,"testdrv",&test_fop);
> if( result != 0 ){
> printk(KERN_WARNING "test: cant get major\n");
> return result;
> }
> i=0;
> memset(temp_struct,0,sizeof(struct test_struct));
> //sprintf(temp_struct->name, DEVNAME "%d",i);
> tempDev = (struct net_device *)kmalloc(sizeof(struct net_device),GFP_KERNEL);
> if( !tempDev)
> {
> printk(KERN_ERR "kmalloc faied\n");
> return -ENOMEM;
> }
> memset(tempDev,0,sizeof(struct net_device));
> temp_struct->dev = tempDev;
> temp_struct->dev->priv = &pTestStruct;
> temp_struct->dev->next = NULL;
> temp_struct->dev->base_addr=0;
> temp_struct->dev->init = test_init_dev;
>
> temp_struct->dev->dev_addr[0]=0xFC;
> temp_struct->dev->dev_addr[1]=0xFC;
> temp_struct->dev->dev_addr[2]=0xA;
> temp_struct->dev->dev_addr[3]=0xB;
> temp_struct->dev->dev_addr[4]=0xC;
> temp_struct->dev->addr_len = ETH_ALEN;
> i = dev_alloc_name(temp_struct->dev,"firsteth%d");
> if(i < 0 )
> {
> printk(KERN_ERR "cant allocate device\n");
> return -ENODEV;
> }
> ether_setup(temp_struct->dev);
> rtnl_lock();
> printk(KERN_INFO "Before calling register_netdevice\n");
> i = register_netdevice((temp_struct->dev));
> rtnl_unlock();
> memcpy(&pTestStruct,temp_struct,sizeof(struct test_struct));
> if( i < 0 ){
> printk(KERN_ERR "register netdevice failed\n");
> return -1;
> }
> return 0;
> }
>
> void cleanup_module(void)
> {
> rtnl_lock();
> unregister_netdevice(pTestStruct.dev);
> rtnl_unlock();
> unregister_chrdev(244,"testdrv");
> }
>
>
>
>
>
>
--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive: http://mail.nl.linux.org/kernelnewbies/
FAQ: http://kernelnewbies.org/faq/
