net/core/dv.c - kernel/msm - Gitiles

 /*
  * INET		An implementation of the TCP/IP protocol suite for the LINUX
  *		operating system.  INET is implemented using the  BSD Socket
  *		interface as the means of communication with the user level.
  *
  *		Generic frame diversion
  *
  * Authors:
  * 		Benoit LOCHER:	initial integration within the kernel with support for ethernet
  * 		Dave Miller:	improvement on the code (correctness, performance and source files)
  *
  */
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/socket.h>
 #include <linux/in.h>
 #include <linux/inet.h>
 #include <linux/ip.h>
 #include <linux/udp.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
 #include <linux/capability.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <net/dst.h>
 #include <net/arp.h>
 #include <net/sock.h>
 #include <net/ipv6.h>
 #include <net/ip.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
 #include <asm/checksum.h>
 #include <linux/divert.h>
 #include <linux/sockios.h>

 const char sysctl_divert_version[32]="0.46";	/* Current version */

 static int __init dv_init(void)
 {
 	return 0;
 }
 module_init(dv_init);

 /*
  * Allocate a divert_blk for a device. This must be an ethernet nic.
  */
 int alloc_divert_blk(struct net_device *dev)
 {
 	int alloc_size = (sizeof(struct divert_blk) + 3) & ~3;

 	dev->divert = NULL;
 	if (dev->type == ARPHRD_ETHER) {
 		dev->divert = (struct divert_blk *)
 			kmalloc(alloc_size, GFP_KERNEL);
 		if (dev->divert == NULL) {
 			printk(KERN_INFO "divert: unable to allocate divert_blk for %s\n",
 			       dev->name);
 			return -ENOMEM;
 		}

 		memset(dev->divert, 0, sizeof(struct divert_blk));
 		dev_hold(dev);
 	}

 	return 0;
 }

 /*
  * Free a divert_blk allocated by the above function, if it was
  * allocated on that device.
  */
 void free_divert_blk(struct net_device *dev)
 {
 	if (dev->divert) {
 		kfree(dev->divert);
 		dev->divert=NULL;
 		dev_put(dev);
 	}
 }

 /*
  * Adds a tcp/udp (source or dest) port to an array
  */
 static int add_port(u16 ports[], u16 port)
 {
 	int i;

 	if (port == 0)
 		return -EINVAL;

 	/* Storing directly in network format for performance,
 	 * thanks Dave :)
 	 */
 	port = htons(port);

 	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
 		if (ports[i] == port)
 			return -EALREADY;
 	}

 	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
 		if (ports[i] == 0) {
 			ports[i] = port;
 			return 0;
 		}
 	}

 	return -ENOBUFS;
 }

 /*
  * Removes a port from an array tcp/udp (source or dest)
  */
 static int remove_port(u16 ports[], u16 port)
 {
 	int i;

 	if (port == 0)
 		return -EINVAL;

 	/* Storing directly in network format for performance,
 	 * thanks Dave !
 	 */
 	port = htons(port);

 	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
 		if (ports[i] == port) {
 			ports[i] = 0;
 			return 0;
 		}
 	}

 	return -EINVAL;
 }

 /* Some basic sanity checks on the arguments passed to divert_ioctl() */
 static int check_args(struct divert_cf *div_cf, struct net_device **dev)
 {
 	char devname[32];
 	int ret;

 	if (dev == NULL)
 		return -EFAULT;

 	/* GETVERSION: all other args are unused */
 	if (div_cf->cmd == DIVCMD_GETVERSION)
 		return 0;

 	/* Network device index should reasonably be between 0 and 1000 :) */
 	if (div_cf->dev_index < 0 || div_cf->dev_index > 1000)
 		return -EINVAL;

 	/* Let's try to find the ifname */
 	sprintf(devname, "eth%d", div_cf->dev_index);
 	*dev = dev_get_by_name(devname);

 	/* dev should NOT be null */
 	if (*dev == NULL)
 		return -EINVAL;

 	ret = 0;

 	/* user issuing the ioctl must be a super one :) */
 	if (!capable(CAP_SYS_ADMIN)) {
 		ret = -EPERM;
 		goto out;
 	}

 	/* Device must have a divert_blk member NOT null */
 	if ((*dev)->divert == NULL)
 		ret = -EINVAL;
 out:
 	dev_put(*dev);
 	return ret;
 }

 /*
  * control function of the diverter
  */
 #if 0
 #define	DVDBG(a)	\
 	printk(KERN_DEBUG "divert_ioctl() line %d %s\n", __LINE__, (a))
 #else
 #define	DVDBG(a)
 #endif

 int divert_ioctl(unsigned int cmd, struct divert_cf __user *arg)
 {
 	struct divert_cf	div_cf;
 	struct divert_blk	*div_blk;
 	struct net_device	*dev;
 	int			ret;

 	switch (cmd) {
 	case SIOCGIFDIVERT:
 		DVDBG("SIOCGIFDIVERT, copy_from_user");
 		if (copy_from_user(&div_cf, arg, sizeof(struct divert_cf)))
 			return -EFAULT;
 		DVDBG("before check_args");
 		ret = check_args(&div_cf, &dev);
 		if (ret)
 			return ret;
 		DVDBG("after checkargs");
 		div_blk = dev->divert;

 		DVDBG("befre switch()");
 		switch (div_cf.cmd) {
 		case DIVCMD_GETSTATUS:
 			/* Now, just give the user the raw divert block
 			 * for him to play with :)
 			 */
 			if (copy_to_user(div_cf.arg1.ptr, dev->divert,
 					 sizeof(struct divert_blk)))
 				return -EFAULT;
 			break;

 		case DIVCMD_GETVERSION:
 			DVDBG("GETVERSION: checking ptr");
 			if (div_cf.arg1.ptr == NULL)
 				return -EINVAL;
 			DVDBG("GETVERSION: copying data to userland");
 			if (copy_to_user(div_cf.arg1.ptr,
 					 sysctl_divert_version, 32))
 				return -EFAULT;
 			DVDBG("GETVERSION: data copied");
 			break;

 		default:
 			return -EINVAL;
 		}

 		break;

 	case SIOCSIFDIVERT:
 		if (copy_from_user(&div_cf, arg, sizeof(struct divert_cf)))
 			return -EFAULT;

 		ret = check_args(&div_cf, &dev);
 		if (ret)
 			return ret;

 		div_blk = dev->divert;

 		switch(div_cf.cmd) {
 		case DIVCMD_RESET:
 			div_blk->divert = 0;
 			div_blk->protos = DIVERT_PROTO_NONE;
 			memset(div_blk->tcp_dst, 0,
 			       MAX_DIVERT_PORTS * sizeof(u16));
 			memset(div_blk->tcp_src, 0,
 			       MAX_DIVERT_PORTS * sizeof(u16));
 			memset(div_blk->udp_dst, 0,
 			       MAX_DIVERT_PORTS * sizeof(u16));
 			memset(div_blk->udp_src, 0,
 			       MAX_DIVERT_PORTS * sizeof(u16));
 			return 0;

 		case DIVCMD_DIVERT:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ENABLE:
 				if (div_blk->divert)
 					return -EALREADY;
 				div_blk->divert = 1;
 				break;

 			case DIVARG1_DISABLE:
 				if (!div_blk->divert)
 					return -EALREADY;
 				div_blk->divert = 0;
 				break;

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_IP:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ENABLE:
 				if (div_blk->protos & DIVERT_PROTO_IP)
 					return -EALREADY;
 				div_blk->protos |= DIVERT_PROTO_IP;
 				break;

 			case DIVARG1_DISABLE:
 				if (!(div_blk->protos & DIVERT_PROTO_IP))
 					return -EALREADY;
 				div_blk->protos &= ~DIVERT_PROTO_IP;
 				break;

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_TCP:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ENABLE:
 				if (div_blk->protos & DIVERT_PROTO_TCP)
 					return -EALREADY;
 				div_blk->protos |= DIVERT_PROTO_TCP;
 				break;

 			case DIVARG1_DISABLE:
 				if (!(div_blk->protos & DIVERT_PROTO_TCP))
 					return -EALREADY;
 				div_blk->protos &= ~DIVERT_PROTO_TCP;
 				break;

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_TCPDST:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ADD:
 				return add_port(div_blk->tcp_dst,
 						div_cf.arg2.uint16);

 			case DIVARG1_REMOVE:
 				return remove_port(div_blk->tcp_dst,
 						   div_cf.arg2.uint16);

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_TCPSRC:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ADD:
 				return add_port(div_blk->tcp_src,
 						div_cf.arg2.uint16);

 			case DIVARG1_REMOVE:
 				return remove_port(div_blk->tcp_src,
 						   div_cf.arg2.uint16);

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_UDP:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ENABLE:
 				if (div_blk->protos & DIVERT_PROTO_UDP)
 					return -EALREADY;
 				div_blk->protos |= DIVERT_PROTO_UDP;
 				break;

 			case DIVARG1_DISABLE:
 				if (!(div_blk->protos & DIVERT_PROTO_UDP))
 					return -EALREADY;
 				div_blk->protos &= ~DIVERT_PROTO_UDP;
 				break;

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_UDPDST:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ADD:
 				return add_port(div_blk->udp_dst,
 						div_cf.arg2.uint16);

 			case DIVARG1_REMOVE:
 				return remove_port(div_blk->udp_dst,
 						   div_cf.arg2.uint16);

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_UDPSRC:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ADD:
 				return add_port(div_blk->udp_src,
 						div_cf.arg2.uint16);

 			case DIVARG1_REMOVE:
 				return remove_port(div_blk->udp_src,
 						   div_cf.arg2.uint16);

 			default:
 				return -EINVAL;
 			}

 			break;

 		case DIVCMD_ICMP:
 			switch(div_cf.arg1.int32) {
 			case DIVARG1_ENABLE:
 				if (div_blk->protos & DIVERT_PROTO_ICMP)
 					return -EALREADY;
 				div_blk->protos |= DIVERT_PROTO_ICMP;
 				break;

 			case DIVARG1_DISABLE:
 				if (!(div_blk->protos & DIVERT_PROTO_ICMP))
 					return -EALREADY;
 				div_blk->protos &= ~DIVERT_PROTO_ICMP;
 				break;

 			default:
 				return -EINVAL;
 			}

 			break;

 		default:
 			return -EINVAL;
 		}

 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }


 /*
  * Check if packet should have its dest mac address set to the box itself
  * for diversion
  */

 #define	ETH_DIVERT_FRAME(skb) \
 	memcpy(eth_hdr(skb), skb->dev->dev_addr, ETH_ALEN); \
 	skb->pkt_type=PACKET_HOST

 void divert_frame(struct sk_buff *skb)
 {
 	struct ethhdr			*eth = eth_hdr(skb);
 	struct iphdr			*iph;
 	struct tcphdr			*tcph;
 	struct udphdr			*udph;
 	struct divert_blk		*divert = skb->dev->divert;
 	int				i, src, dst;
 	unsigned char			*skb_data_end = skb->data + skb->len;

 	/* Packet is already aimed at us, return */
 	if (!compare_ether_addr(eth->h_dest, skb->dev->dev_addr))
 		return;

 	/* proto is not IP, do nothing */
 	if (eth->h_proto != htons(ETH_P_IP))
 		return;

 	/* Divert all IP frames ? */
 	if (divert->protos & DIVERT_PROTO_IP) {
 		ETH_DIVERT_FRAME(skb);
 		return;
 	}

 	/* Check for possible (maliciously) malformed IP frame (thanks Dave) */
 	iph = (struct iphdr *) skb->data;
 	if (((iph->ihl<<2)+(unsigned char*)(iph)) >= skb_data_end) {
 		printk(KERN_INFO "divert: malformed IP packet !\n");
 		return;
 	}

 	switch (iph->protocol) {
 	/* Divert all ICMP frames ? */
 	case IPPROTO_ICMP:
 		if (divert->protos & DIVERT_PROTO_ICMP) {
 			ETH_DIVERT_FRAME(skb);
 			return;
 		}
 		break;

 	/* Divert all TCP frames ? */
 	case IPPROTO_TCP:
 		if (divert->protos & DIVERT_PROTO_TCP) {
 			ETH_DIVERT_FRAME(skb);
 			return;
 		}

 		/* Check for possible (maliciously) malformed IP
 		 * frame (thanx Dave)
 		 */
 		tcph = (struct tcphdr *)
 			(((unsigned char *)iph) + (iph->ihl<<2));
 		if (((unsigned char *)(tcph+1)) >= skb_data_end) {
 			printk(KERN_INFO "divert: malformed TCP packet !\n");
 			return;
 		}

 		/* Divert some tcp dst/src ports only ?*/
 		for (i = 0; i < MAX_DIVERT_PORTS; i++) {
 			dst = divert->tcp_dst[i];
 			src = divert->tcp_src[i];
 			if ((dst && dst == tcph->dest) ||
 			    (src && src == tcph->source)) {
 				ETH_DIVERT_FRAME(skb);
 				return;
 			}
 		}
 		break;

 	/* Divert all UDP frames ? */
 	case IPPROTO_UDP:
 		if (divert->protos & DIVERT_PROTO_UDP) {
 			ETH_DIVERT_FRAME(skb);
 			return;
 		}

 		/* Check for possible (maliciously) malformed IP
 		 * packet (thanks Dave)
 		 */
 		udph = (struct udphdr *)
 			(((unsigned char *)iph) + (iph->ihl<<2));
 		if (((unsigned char *)(udph+1)) >= skb_data_end) {
 			printk(KERN_INFO
 			       "divert: malformed UDP packet !\n");
 			return;
 		}

 		/* Divert some udp dst/src ports only ? */
 		for (i = 0; i < MAX_DIVERT_PORTS; i++) {
 			dst = divert->udp_dst[i];
 			src = divert->udp_src[i];
 			if ((dst && dst == udph->dest) ||
 			    (src && src == udph->source)) {
 				ETH_DIVERT_FRAME(skb);
 				return;
 			}
 		}
 		break;
 	}
 }
	/*
	* INET An implementation of the TCP/IP protocol suite for the LINUX
	* operating system. INET is implemented using the BSD Socket
	* interface as the means of communication with the user level.
	*
	* Generic frame diversion
	*
	* Authors:
	* Benoit LOCHER: initial integration within the kernel with support for ethernet
	* Dave Miller: improvement on the code (correctness, performance and source files)
	*
	*/
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/string.h>
	#include <linux/mm.h>
	#include <linux/socket.h>
	#include <linux/in.h>
	#include <linux/inet.h>
	#include <linux/ip.h>
	#include <linux/udp.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/skbuff.h>
	#include <linux/capability.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <net/dst.h>
	#include <net/arp.h>
	#include <net/sock.h>
	#include <net/ipv6.h>
	#include <net/ip.h>
	#include <asm/uaccess.h>
	#include <asm/system.h>
	#include <asm/checksum.h>
	#include <linux/divert.h>
	#include <linux/sockios.h>

	const char sysctl_divert_version[32]="0.46"; /* Current version */

	static int __init dv_init(void)
	{
	return 0;
	}
	module_init(dv_init);

	/*
	* Allocate a divert_blk for a device. This must be an ethernet nic.
	*/
	int alloc_divert_blk(struct net_device *dev)
	{
	int alloc_size = (sizeof(struct divert_blk) + 3) & ~3;

	dev->divert = NULL;
	if (dev->type == ARPHRD_ETHER) {
	dev->divert = (struct divert_blk *)
	kmalloc(alloc_size, GFP_KERNEL);
	if (dev->divert == NULL) {
	printk(KERN_INFO "divert: unable to allocate divert_blk for %s\n",
	dev->name);
	return -ENOMEM;
	}

	memset(dev->divert, 0, sizeof(struct divert_blk));
	dev_hold(dev);
	}

	return 0;
	}

	/*
	* Free a divert_blk allocated by the above function, if it was
	* allocated on that device.
	*/
	void free_divert_blk(struct net_device *dev)
	{
	if (dev->divert) {
	kfree(dev->divert);
	dev->divert=NULL;
	dev_put(dev);
	}
	}

	/*
	* Adds a tcp/udp (source or dest) port to an array
	*/
	static int add_port(u16 ports[], u16 port)
	{
	int i;

	if (port == 0)
	return -EINVAL;

	/* Storing directly in network format for performance,
	* thanks Dave :)
	*/
	port = htons(port);

	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
	if (ports[i] == port)
	return -EALREADY;
	}

	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
	if (ports[i] == 0) {
	ports[i] = port;
	return 0;
	}
	}

	return -ENOBUFS;
	}

	/*
	* Removes a port from an array tcp/udp (source or dest)
	*/
	static int remove_port(u16 ports[], u16 port)
	{
	int i;

	if (port == 0)
	return -EINVAL;

	/* Storing directly in network format for performance,
	* thanks Dave !
	*/
	port = htons(port);

	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
	if (ports[i] == port) {
	ports[i] = 0;
	return 0;
	}
	}

	return -EINVAL;
	}

	/* Some basic sanity checks on the arguments passed to divert_ioctl() */
	static int check_args(struct divert_cf div_cf, struct net_device *dev)
	{
	char devname[32];
	int ret;

	if (dev == NULL)
	return -EFAULT;

	/* GETVERSION: all other args are unused */
	if (div_cf->cmd == DIVCMD_GETVERSION)
	return 0;

	/* Network device index should reasonably be between 0 and 1000 :) */
	if (div_cf->dev_index < 0 \|\| div_cf->dev_index > 1000)
	return -EINVAL;

	/* Let's try to find the ifname */
	sprintf(devname, "eth%d", div_cf->dev_index);
	*dev = dev_get_by_name(devname);

	/* dev should NOT be null */
	if (*dev == NULL)
	return -EINVAL;

	ret = 0;

	/* user issuing the ioctl must be a super one :) */
	if (!capable(CAP_SYS_ADMIN)) {
	ret = -EPERM;
	goto out;
	}

	/* Device must have a divert_blk member NOT null */
	if ((*dev)->divert == NULL)
	ret = -EINVAL;
	out:
	dev_put(*dev);
	return ret;
	}

	/*
	* control function of the diverter
	*/
	#if 0
	#define DVDBG(a) \
	printk(KERN_DEBUG "divert_ioctl() line %d %s\n", __LINE__, (a))
	#else
	#define DVDBG(a)
	#endif

	int divert_ioctl(unsigned int cmd, struct divert_cf __user *arg)
	{
	struct divert_cf div_cf;
	struct divert_blk *div_blk;
	struct net_device *dev;
	int ret;

	switch (cmd) {
	case SIOCGIFDIVERT:
	DVDBG("SIOCGIFDIVERT, copy_from_user");
	if (copy_from_user(&div_cf, arg, sizeof(struct divert_cf)))
	return -EFAULT;
	DVDBG("before check_args");
	ret = check_args(&div_cf, &dev);
	if (ret)
	return ret;
	DVDBG("after checkargs");
	div_blk = dev->divert;

	DVDBG("befre switch()");
	switch (div_cf.cmd) {
	case DIVCMD_GETSTATUS:
	/* Now, just give the user the raw divert block
	* for him to play with :)
	*/
	if (copy_to_user(div_cf.arg1.ptr, dev->divert,
	sizeof(struct divert_blk)))
	return -EFAULT;
	break;

	case DIVCMD_GETVERSION:
	DVDBG("GETVERSION: checking ptr");
	if (div_cf.arg1.ptr == NULL)
	return -EINVAL;
	DVDBG("GETVERSION: copying data to userland");
	if (copy_to_user(div_cf.arg1.ptr,
	sysctl_divert_version, 32))
	return -EFAULT;
	DVDBG("GETVERSION: data copied");
	break;

	default:
	return -EINVAL;
	}

	break;

	case SIOCSIFDIVERT:
	if (copy_from_user(&div_cf, arg, sizeof(struct divert_cf)))
	return -EFAULT;

	ret = check_args(&div_cf, &dev);
	if (ret)
	return ret;

	div_blk = dev->divert;

	switch(div_cf.cmd) {
	case DIVCMD_RESET:
	div_blk->divert = 0;
	div_blk->protos = DIVERT_PROTO_NONE;
	memset(div_blk->tcp_dst, 0,
	MAX_DIVERT_PORTS * sizeof(u16));
	memset(div_blk->tcp_src, 0,
	MAX_DIVERT_PORTS * sizeof(u16));
	memset(div_blk->udp_dst, 0,
	MAX_DIVERT_PORTS * sizeof(u16));
	memset(div_blk->udp_src, 0,
	MAX_DIVERT_PORTS * sizeof(u16));
	return 0;

	case DIVCMD_DIVERT:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ENABLE:
	if (div_blk->divert)
	return -EALREADY;
	div_blk->divert = 1;
	break;

	case DIVARG1_DISABLE:
	if (!div_blk->divert)
	return -EALREADY;
	div_blk->divert = 0;
	break;

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_IP:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ENABLE:
	if (div_blk->protos & DIVERT_PROTO_IP)
	return -EALREADY;
	div_blk->protos \|= DIVERT_PROTO_IP;
	break;

	case DIVARG1_DISABLE:
	if (!(div_blk->protos & DIVERT_PROTO_IP))
	return -EALREADY;
	div_blk->protos &= ~DIVERT_PROTO_IP;
	break;

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_TCP:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ENABLE:
	if (div_blk->protos & DIVERT_PROTO_TCP)
	return -EALREADY;
	div_blk->protos \|= DIVERT_PROTO_TCP;
	break;

	case DIVARG1_DISABLE:
	if (!(div_blk->protos & DIVERT_PROTO_TCP))
	return -EALREADY;
	div_blk->protos &= ~DIVERT_PROTO_TCP;
	break;

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_TCPDST:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ADD:
	return add_port(div_blk->tcp_dst,
	div_cf.arg2.uint16);

	case DIVARG1_REMOVE:
	return remove_port(div_blk->tcp_dst,
	div_cf.arg2.uint16);

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_TCPSRC:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ADD:
	return add_port(div_blk->tcp_src,
	div_cf.arg2.uint16);

	case DIVARG1_REMOVE:
	return remove_port(div_blk->tcp_src,
	div_cf.arg2.uint16);

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_UDP:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ENABLE:
	if (div_blk->protos & DIVERT_PROTO_UDP)
	return -EALREADY;
	div_blk->protos \|= DIVERT_PROTO_UDP;
	break;

	case DIVARG1_DISABLE:
	if (!(div_blk->protos & DIVERT_PROTO_UDP))
	return -EALREADY;
	div_blk->protos &= ~DIVERT_PROTO_UDP;
	break;

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_UDPDST:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ADD:
	return add_port(div_blk->udp_dst,
	div_cf.arg2.uint16);

	case DIVARG1_REMOVE:
	return remove_port(div_blk->udp_dst,
	div_cf.arg2.uint16);

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_UDPSRC:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ADD:
	return add_port(div_blk->udp_src,
	div_cf.arg2.uint16);

	case DIVARG1_REMOVE:
	return remove_port(div_blk->udp_src,
	div_cf.arg2.uint16);

	default:
	return -EINVAL;
	}

	break;

	case DIVCMD_ICMP:
	switch(div_cf.arg1.int32) {
	case DIVARG1_ENABLE:
	if (div_blk->protos & DIVERT_PROTO_ICMP)
	return -EALREADY;
	div_blk->protos \|= DIVERT_PROTO_ICMP;
	break;

	case DIVARG1_DISABLE:
	if (!(div_blk->protos & DIVERT_PROTO_ICMP))
	return -EALREADY;
	div_blk->protos &= ~DIVERT_PROTO_ICMP;
	break;

	default:
	return -EINVAL;
	}

	break;

	default:
	return -EINVAL;
	}

	break;

	default:
	return -EINVAL;
	}

	return 0;
	}


	/*
	* Check if packet should have its dest mac address set to the box itself
	* for diversion
	*/

	#define ETH_DIVERT_FRAME(skb) \
	memcpy(eth_hdr(skb), skb->dev->dev_addr, ETH_ALEN); \
	skb->pkt_type=PACKET_HOST

	void divert_frame(struct sk_buff *skb)
	{
	struct ethhdr *eth = eth_hdr(skb);
	struct iphdr *iph;
	struct tcphdr *tcph;
	struct udphdr *udph;
	struct divert_blk *divert = skb->dev->divert;
	int i, src, dst;
	unsigned char *skb_data_end = skb->data + skb->len;

	/* Packet is already aimed at us, return */
	if (!compare_ether_addr(eth->h_dest, skb->dev->dev_addr))
	return;

	/* proto is not IP, do nothing */
	if (eth->h_proto != htons(ETH_P_IP))
	return;

	/* Divert all IP frames ? */
	if (divert->protos & DIVERT_PROTO_IP) {
	ETH_DIVERT_FRAME(skb);
	return;
	}

	/* Check for possible (maliciously) malformed IP frame (thanks Dave) */
	iph = (struct iphdr *) skb->data;
	if (((iph->ihl<<2)+(unsigned char*)(iph)) >= skb_data_end) {
	printk(KERN_INFO "divert: malformed IP packet !\n");
	return;
	}

	switch (iph->protocol) {
	/* Divert all ICMP frames ? */
	case IPPROTO_ICMP:
	if (divert->protos & DIVERT_PROTO_ICMP) {
	ETH_DIVERT_FRAME(skb);
	return;
	}
	break;

	/* Divert all TCP frames ? */
	case IPPROTO_TCP:
	if (divert->protos & DIVERT_PROTO_TCP) {
	ETH_DIVERT_FRAME(skb);
	return;
	}

	/* Check for possible (maliciously) malformed IP
	* frame (thanx Dave)
	*/
	tcph = (struct tcphdr *)
	(((unsigned char *)iph) + (iph->ihl<<2));
	if (((unsigned char *)(tcph+1)) >= skb_data_end) {
	printk(KERN_INFO "divert: malformed TCP packet !\n");
	return;
	}

	/* Divert some tcp dst/src ports only ?*/
	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
	dst = divert->tcp_dst[i];
	src = divert->tcp_src[i];
	if ((dst && dst == tcph->dest) \|\|
	(src && src == tcph->source)) {
	ETH_DIVERT_FRAME(skb);
	return;
	}
	}
	break;

	/* Divert all UDP frames ? */
	case IPPROTO_UDP:
	if (divert->protos & DIVERT_PROTO_UDP) {
	ETH_DIVERT_FRAME(skb);
	return;
	}

	/* Check for possible (maliciously) malformed IP
	* packet (thanks Dave)
	*/
	udph = (struct udphdr *)
	(((unsigned char *)iph) + (iph->ihl<<2));
	if (((unsigned char *)(udph+1)) >= skb_data_end) {
	printk(KERN_INFO
	"divert: malformed UDP packet !\n");
	return;
	}

	/* Divert some udp dst/src ports only ? */
	for (i = 0; i < MAX_DIVERT_PORTS; i++) {
	dst = divert->udp_dst[i];
	src = divert->udp_src[i];
	if ((dst && dst == udph->dest) \|\|
	(src && src == udph->source)) {
	ETH_DIVERT_FRAME(skb);
	return;
	}
	}
	break;
	}
	}