path: root/net/core/pktgen.c

/*
 * Authors:
 * Copyright 2001, 2002 by Robert Olsson <robert.olsson@its.uu.se>
 *                             Uppsala University and
 *                             Swedish University of Agricultural Sciences
 *
 * Alexey Kuznetsov  <kuznet@ms2.inr.ac.ru>
 * Ben Greear <greearb@candelatech.com>
 * Jens Lĺĺs <jens.laas@data.slu.se>
 *
 * 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.
 *
 *
 * A tool for loading the network with preconfigurated packets.
 * The tool is implemented as a linux module.  Parameters are output 
 * device, delay (to hard_xmit), number of packets, and whether
 * to use multiple SKBs or just the same one.
 * pktgen uses the installed interface's output routine.
 *
 * Additional hacking by:
 *
 * Jens.Laas@data.slu.se
 * Improved by ANK. 010120.
 * Improved by ANK even more. 010212.
 * MAC address typo fixed. 010417 --ro
 * Integrated.  020301 --DaveM
 * Added multiskb option 020301 --DaveM
 * Scaling of results. 020417--sigurdur@linpro.no
 * Significant re-work of the module:
 *   *  Convert to threaded model to more efficiently be able to transmit
 *       and receive on multiple interfaces at once.
 *   *  Converted many counters to __u64 to allow longer runs.
 *   *  Allow configuration of ranges, like min/max IP address, MACs,
 *       and UDP-ports, for both source and destination, and can
 *       set to use a random distribution or sequentially walk the range.
 *   *  Can now change most values after starting.
 *   *  Place 12-byte packet in UDP payload with magic number,
 *       sequence number, and timestamp.
 *   *  Add receiver code that detects dropped pkts, re-ordered pkts, and
 *       latencies (with micro-second) precision.
 *   *  Add IOCTL interface to easily get counters & configuration.
 *   --Ben Greear <greearb@candelatech.com>
 *
 * Renamed multiskb to clone_skb and cleaned up sending core for two distinct 
 * skb modes. A clone_skb=0 mode for Ben "ranges" work and a clone_skb != 0 
 * as a "fastpath" with a configurable number of clones after alloc's.
 * clone_skb=0 means all packets are allocated this also means ranges time 
 * stamps etc can be used. clone_skb=100 means 1 malloc is followed by 100 
 * clones.
 *
 * Also moved to /proc/net/pktgen/ 
 * --ro
 *
 * Sept 10:  Fixed threading/locking.  Lots of bone-headed and more clever
 *    mistakes.  Also merged in DaveM's patch in the -pre6 patch.
 * --Ben Greear <greearb@candelatech.com>
 *
 * Integrated to 2.5.x 021029 --Lucio Maciel (luciomaciel@zipmail.com.br)
 *
 * 
 * 021124 Finished major redesign and rewrite for new functionality.
 * See Documentation/networking/pktgen.txt for how to use this.
 *
 * The new operation:
 * For each CPU one thread/process is created at start. This process checks 
 * for running devices in the if_list and sends packets until count is 0 it 
 * also the thread checks the thread->control which is used for inter-process 
 * communication. controlling process "posts" operations to the threads this 
 * way. The if_lock should be possible to remove when add/rem_device is merged
 * into this too.
 *
 * By design there should only be *one* "controlling" process. In practice 
 * multiple write accesses gives unpredictable result. Understood by "write" 
 * to /proc gives result code thats should be read be the "writer".
 * For practical use this should be no problem.
 *
 * Note when adding devices to a specific CPU there good idea to also assign 
 * /proc/irq/XX/smp_affinity so TX-interrupts gets bound to the same CPU. 
 * --ro
 *
 * Fix refcount off by one if first packet fails, potential null deref, 
 * memleak 030710- KJP
 *
 * First "ranges" functionality for ipv6 030726 --ro
 *
 * Included flow support. 030802 ANK.
 *
 * Fixed unaligned access on IA-64 Grant Grundler <grundler@parisc-linux.org>
 * 
 * Remove if fix from added Harald Welte <laforge@netfilter.org> 040419
 * ia64 compilation fix from  Aron Griffis <aron@hp.com> 040604
 *
 * New xmit() return, do_div and misc clean up by Stephen Hemminger 
 * <shemminger@osdl.org> 040923
 *
 * Randy Dunlap fixed u64 printk compiler waring 
 *
 * Remove FCS from BW calculation.  Lennert Buytenhek <buytenh@wantstofly.org>
 * New time handling. Lennert Buytenhek <buytenh@wantstofly.org> 041213
 *
 * Corrections from Nikolai Malykh (nmalykh@bilim.com) 
 * Removed unused flags F_SET_SRCMAC & F_SET_SRCIP 041230
 *
 * interruptible_sleep_on_timeout() replaced Nishanth Aravamudan <nacc@us.ibm.com> 
 * 050103
 */
#include <linux/sys.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/smp_lock.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/rtnetlink.h>
#include <linux/if_arp.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/udp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/wait.h>
#include <linux/etherdevice.h>
#include <net/checksum.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <asm/byteorder.h>
#include <linux/rcupdate.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>
#include <asm/div64.h>		/* do_div */
#include <asm/timex.h>

#define VERSION  "pktgen v2.66: Packet Generator for packet performance testing.\n"

/* #define PG_DEBUG(a) a */
#define PG_DEBUG(a)

/* The buckets are exponential in 'width' */
#define LAT_BUCKETS_MAX 32
#define IP_NAME_SZ 32

/* Device flag bits */
#define F_IPSRC_RND   (1<<0)	/* IP-Src Random  */
#define F_IPDST_RND   (1<<1)	/* IP-Dst Random  */
#define F_UDPSRC_RND  (1<<2)	/* UDP-Src Random */
#define F_UDPDST_RND  (1<<3)	/* UDP-Dst Random */
#define F_MACSRC_RND  (1<<4)	/* MAC-Src Random */
#define F_MACDST_RND  (1<<5)	/* MAC-Dst Random */
#define F_TXSIZE_RND  (1<<6)	/* Transmit size is random */
#define F_IPV6        (1<<7)	/* Interface in IPV6 Mode */

/* Thread control flag bits */
#define T_TERMINATE   (1<<0)
#define T_STOP        (1<<1)	/* Stop run */
#define T_RUN         (1<<2)	/* Start run */
#define T_REMDEVALL   (1<<3)	/* Remove all devs */
#define T_REMDEV      (1<<4)	/* Remove one dev */

/* If lock -- can be removed after some work */
#define   if_lock(t)           spin_lock(&(t->if_lock));
#define   if_unlock(t)           spin_unlock(&(t->if_lock));

/* Used to help with determining the pkts on receive */
#define PKTGEN_MAGIC 0xbe9be955
#define PG_PROC_DIR "pktgen"
#define PGCTRL	    "pgctrl"
static struct proc_dir_entry *pg_proc_dir = NULL;

#define MAX_CFLOWS  65536

struct flow_state {
	__u32 cur_daddr;
	int count;
};

struct pktgen_dev {

	/*
	 * Try to keep frequent/infrequent used vars. separated.
	 */

	char ifname[IFNAMSIZ];
	char result[512];

	struct pktgen_thread *pg_thread;	/* the owner */
	struct list_head list;		/* Used for chaining in the thread's run-queue */

	int running;		/* if this changes to false, the test will stop */

	/* If min != max, then we will either do a linear iteration, or
	 * we will do a random selection from within the range.
	 */
	__u32 flags;
	int removal_mark;	/* non-zero => the device is marked for
				 * removal by worker thread */

	int min_pkt_size;	/* = ETH_ZLEN; */
	int max_pkt_size;	/* = ETH_ZLEN; */
	int nfrags;
	__u32 delay_us;		/* Default delay */
	__u32 delay_ns;
	__u64 count;		/* Default No packets to send */
	__u64 sofar;		/* How many pkts we've sent so far */
	__u64 tx_bytes;		/* How many bytes we've transmitted */
	__u64 errors;		/* Errors when trying to transmit, pkts will be re-sent */

	/* runtime counters relating to clone_skb */
	__u64 next_tx_us;	/* timestamp of when to tx next */
	__u32 next_tx_ns;

	__u64 allocated_skbs;
	__u32 clone_count;
	int last_ok;		/* Was last skb sent?
				 * Or a failed transmit of some sort?  This will keep
				 * sequence numbers in order, for example.
				 */
	__u64 started_at;	/* micro-seconds */
	__u64 stopped_at;	/* micro-seconds */
	__u64 idle_acc;		/* micro-seconds */
	__u32 seq_num;

	int clone_skb;		/* Use multiple SKBs during packet gen.  If this number
				 * is greater than 1, then that many copies of the same
				 * packet will be sent before a new packet is allocated.
				 * For instance, if you want to send 1024 identical packets
				 * before creating a new packet, set clone_skb to 1024.
				 */

	char dst_min[IP_NAME_SZ];	/* IP, ie 1.2.3.4 */
	char dst_max[IP_NAME_SZ];	/* IP, ie 1.2.3.4 */
	char src_min[IP_NAME_SZ];	/* IP, ie 1.2.3.4 */
	char src_max[IP_NAME_SZ];	/* IP, ie 1.2.3.4 */

	struct in6_addr in6_saddr;
	struct in6_addr in6_daddr;
	struct in6_addr cur_in6_daddr;
	struct in6_addr cur_in6_saddr;
	/* For ranges */
	struct in6_addr min_in6_daddr;
	struct in6_addr max_in6_daddr;
	struct in6_addr min_in6_saddr;
	struct in6_addr max_in6_saddr;

	/* If we're doing ranges, random or incremental, then this
	 * defines the min/max for those ranges.
	 */
	__u32 saddr_min;	/* inclusive, source IP address */
	__u32 saddr_max;	/* exclusive, source IP address */
	__u32 daddr_min;	/* inclusive, dest IP address */
	__u32 daddr_max;	/* exclusive, dest IP address */

	__u16 udp_src_min;	/* inclusive, source UDP port */
	__u16 udp_src_max;	/* exclusive, source UDP port */
	__u16 udp_dst_min;	/* inclusive, dest UDP port */
	__u16 udp_dst_max;	/* exclusive, dest UDP port */

	__u32 src_mac_count;	/* How many MACs to iterate through */
	__u32 dst_mac_count;	/* How many MACs to iterate through */

	unsigned char dst_mac[ETH_ALEN];
	unsigned char src_mac[ETH_ALEN];

	__u32 cur_dst_mac_offset;
	__u32 cur_src_mac_offset;
	__u32 cur_saddr;
	__u32 cur_daddr;
	__u16 cur_udp_dst;
	__u16 cur_udp_src;
	__u32 cur_pkt_size;

	__u8 hh[14];
	/* = {
	   0x00, 0x80, 0xC8, 0x79, 0xB3, 0xCB,

	   We fill in SRC address later
	   0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	   0x08, 0x00
	   };
	 */
	__u16 pad;		/* pad out the hh struct to an even 16 bytes */

	struct sk_buff *skb;	/* skb we are to transmit next, mainly used for when we
				 * are transmitting the same one multiple times
				 */
	struct net_device *odev;	/* The out-going device.  Note that the device should
					 * have it's pg_info pointer pointing back to this
					 * device.  This will be set when the user specifies
					 * the out-going device name (not when the inject is
					 * started as it used to do.)
					 */
	struct flow_state *flows;
	unsigned cflows;	/* Concurrent flows (config) */
	unsigned lflow;		/* Flow length  (config) */
	unsigned nflows;	/* accumulated flows (stats) */
};

struct pktgen_hdr {
	__u32 pgh_magic;
	__u32 seq_num;
	__u32 tv_sec;
	__u32 tv_usec;
};

struct pktgen_thread {
	spinlock_t if_lock;
	struct list_head if_list;	/* All device here */
	struct list_head th_list;
	int removed;
	char name[32];
	char result[512];
	u32 max_before_softirq;	/* We'll call do_softirq to prevent starvation. */

	/* Field for thread to receive "posted" events terminate, stop ifs etc. */

	u32 control;
	int pid;
	int cpu;

	wait_queue_head_t queue;
};

#define REMOVE 1
#define FIND   0

/*  This code works around the fact that do_div cannot handle two 64-bit
    numbers, and regular 64-bit division doesn't work on x86 kernels.
    --Ben
*/

#define PG_DIV 0

/* This was emailed to LMKL by: Chris Caputo <ccaputo@alt.net>
 * Function copied/adapted/optimized from:
 *
 *  nemesis.sourceforge.net/browse/lib/static/intmath/ix86/intmath.c.html
 *
 * Copyright 1994, University of Cambridge Computer Laboratory
 * All Rights Reserved.
 *
 */
static inline s64 divremdi3(s64 x, s64 y, int type)
{
	u64 a = (x < 0) ? -x : x;
	u64 b = (y < 0) ? -y : y;
	u64 res = 0, d = 1;

	if (b > 0) {
		while (b < a) {
			b <<= 1;
			d <<= 1;
		}
	}

	do {
		if (a >= b) {
			a -= b;
			res += d;
		}
		b >>= 1;
		d >>= 1;
	}
	while (d);

	if (PG_DIV == type) {
		return (((x ^ y) & (1ll << 63)) == 0) ? res : -(s64) res;
	} else {
		return ((x & (1ll << 63)) == 0) ? a : -(s64) a;
	}
}

/* End of hacks to deal with 64-bit math on x86 */

/** Convert to milliseconds */
static inline __u64 tv_to_ms(const struct timeval *tv)
{
	__u64 ms = tv->tv_usec / 1000;
	ms += (__u64) tv->tv_sec * (__u64) 1000;
	return ms;
}

/** Convert to micro-seconds */
static inline __u64 tv_to_us(const struct timeval *tv)
{
	__u64 us = tv->tv_usec;
	us += (__u64) tv->tv_sec * (__u64) 1000000;
	return us;
}

static inline __u64 pg_div(__u64 n, __u32 base)
{
	__u64 tmp = n;
	do_div(tmp, base);
	/* printk("pktgen: pg_div, n: %llu  base: %d  rv: %llu\n",
	   n, base, tmp); */
	return tmp;
}

static inline __u64 pg_div64(__u64 n, __u64 base)
{
	__u64 tmp = n;
/*
 * How do we know if the architecture we are running on
 * supports division with 64 bit base?
 * 
 */
#if defined(__sparc_v9__) || defined(__powerpc64__) || defined(__alpha__) || defined(__x86_64__) || defined(__ia64__)

	do_div(tmp, base);
#else
	tmp = divremdi3(n, base, PG_DIV);
#endif
	return tmp;
}

static inline u32 pktgen_random(void)
{
#if 0
	__u32 n;
	get_random_bytes(&n, 4);
	return n;
#else
	return net_random();
#endif
}

static inline __u64 getCurMs(void)
{
	struct timeval tv;
	do_gettimeofday(&tv);
	return tv_to_ms(&tv);
}

static inline __u64 getCurUs(void)
{
	struct timeval tv;
	do_gettimeofday(&tv);
	return tv_to_us(&tv);
}

static inline __u64 tv_diff(const struct timeval *a, const struct timeval *b)
{
	return tv_to_us(a) - tv_to_us(b);
}

/* old include end */

static char version[] __initdata = VERSION;

static int pktgen_remove_device(struct pktgen_thread *t, struct pktgen_dev *i);
static int pktgen_add_device(struct pktgen_thread *t, const char *ifname);
static struct pktgen_dev *pktgen_find_dev(struct pktgen_thread *t,
					  const char *ifname);
static int pktgen_device_event(struct notifier_block *, unsigned long, void *);
static void pktgen_run_all_threads(void);
static void pktgen_stop_all_threads_ifs(void);
static int pktgen_stop_device(struct pktgen_dev *pkt_dev);
static void pktgen_stop(struct pktgen_thread *t);
static void pktgen_clear_counters(struct pktgen_dev *pkt_dev);
static int pktgen_mark_device(const char *ifname);
static unsigned int scan_ip6(const char *s, char ip[16]);
static unsigned int fmt_ip6(char *s, const char ip[16]);

/* Module parameters, defaults. */
static int pg_count_d = 1000;	/* 1000 pkts by default */
static int pg_delay_d;
static int pg_clone_skb_d;
static int debug;

static DEFINE_MUTEX(pktgen_thread_lock);
static LIST_HEAD(pktgen_threads);

static struct notifier_block pktgen_notifier_block = {
	.notifier_call = pktgen_device_event,
};

/*
 * /proc handling functions 
 *
 */

static int pgctrl_show(struct seq_file *seq, void *v)
{
	seq_puts(seq, VERSION);
	return 0;
}

static ssize_t pgctrl_write(struct file *file, const char __user * buf,
			    size_t count, loff_t * ppos)
{
	int err = 0;
	char data[128];

	if (!capable(CAP_NET_ADMIN)) {
		err = -EPERM;
		goto out;
	}

	if (count > sizeof(data))
		count = sizeof(data);

	if (copy_from_user(data, buf, count)) {
		err = -EFAULT;
		goto out;
	}
	data[count - 1] = 0;	/* Make string */

	if (!strcmp(data, "stop"))
		pktgen_stop_all_threads_ifs();

	else if (!strcmp(data, "start"))
		pktgen_run_all_threads();

	else
		printk("pktgen: Unknown command: %s\n", data);

	err = count;

out:
	return err;
}

static int pgctrl_open(struct inode *inode, struct file *file)
{
	return single_open(file, pgctrl_show, PDE(inode)->data);
}

static struct file_operations pktgen_fops = {
	.owner   = THIS_MODULE,
	.open    = pgctrl_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.write   = pgctrl_write,
	.release = single_release,
};

static int pktgen_if_show(struct seq_file *seq, void *v)
{
	int i;
	struct pktgen_dev *pkt_dev = seq->private;
	__u64 sa;
	__u64 stopped;
	__u64 now = getCurUs();

	seq_printf(seq,
		   "Params: count %llu  min_pkt_size: %u  max_pkt_size: %u\n",
		   (unsigned long long)pkt_dev->count, pkt_dev->min_pkt_size,
		   pkt_dev->max_pkt_size);

	seq_printf(seq,
		   "     frags: %d  delay: %u  clone_skb: %d  ifname: %s\n",
		   pkt_dev->nfrags,
		   1000 * pkt_dev->delay_us + pkt_dev->delay_ns,
		   pkt_dev->clone_skb, pkt_dev->ifname);

	seq_printf(seq, "     flows: %u flowlen: %u\n", pkt_dev->cflows,
		   pkt_dev->lflow);

	if (pkt_dev->flags & F_IPV6) {
		char b1[128], b2[128], b3[128];
		fmt_ip6(b1, pkt_dev->in6_saddr.s6_addr);
		fmt_ip6(b2, pkt_dev->min_in6_saddr.s6_addr);
		fmt_ip6(b3, pkt_dev->max_in6_saddr.s6_addr);
		seq_printf(seq,
			   "     saddr: %s  min_saddr: %s  max_saddr: %s\n", b1,
			   b2, b3);

		fmt_ip6(b1, pkt_dev->in6_daddr.s6_addr);
		fmt_ip6(b2, pkt_dev->min_in6_daddr.s6_addr);
		fmt_ip6(b3, pkt_dev->max_in6_daddr.s6_addr);
		seq_printf(seq,
			   "     daddr: %s  min_daddr: %s  max_daddr: %s\n", b1,
			   b2, b3);

	} else
		seq_printf(seq,
			   "     dst_min: %s  dst_max: %s\n     src_min: %s  src_max: %s\n",
			   pkt_dev->dst_min, pkt_dev->dst_max, pkt_dev->src_min,
			   pkt_dev->src_max);

	seq_puts(seq, "     src_mac: ");

	if (is_zero_ether_addr(pkt_dev->src_mac))
		for (i = 0; i < 6; i++)
			seq_printf(seq, "%02X%s", pkt_dev->odev->dev_addr[i],
				   i == 5 ? "  " : ":");
	else
		for (i = 0; i < 6; i++)
			seq_printf(seq, "%02X%s", pkt_dev->src_mac[i],
				   i == 5 ? "  " : ":");

	seq_printf(seq, "dst_mac: ");
	for (i = 0; i < 6; i++)
		seq_printf(seq, "%02X%s", pkt_dev->dst_mac[i],
			   i == 5 ? "\n" : ":");

	seq_printf(seq,
		   "     udp_src_min: %d  udp_src_max: %d  udp_dst_min: %d  udp_dst_max: %d\n",
		   pkt_dev->udp_src_min, pkt_dev->udp_src_max,
		   pkt_dev->udp_dst_min, pkt_dev->udp_dst_max);

	seq_printf(seq,
		   "     src_mac_count: %d  dst_mac_count: %d \n     Flags: ",
		   pkt_dev->src_mac_count, pkt_dev->dst_mac_count);

	if (pkt_dev->flags & F_IPV6)
		seq_printf(seq, "IPV6  ");

	if (pkt_dev->flags & F_IPSRC_RND)
		seq_printf(seq, "IPSRC_RND  ");

	if (pkt_dev->flags & F_IPDST_RND)
		seq_printf(seq, "IPDST_RND  ");

	if (pkt_dev->flags & F_TXSIZE_RND)
		seq_printf(seq, "TXSIZE_RND  ");

	if (pkt_dev->flags & F_UDPSRC_RND)
		seq_printf(seq, "UDPSRC_RND  ");

	if (pkt_dev->flags & F_UDPDST_RND)
		seq_printf(seq, "UDPDST_RND  ");

	if (pkt_dev->flags & F_MACSRC_RND)
		seq_printf(seq, "MACSRC_RND  ");

	if (pkt_dev->flags & F_MACDST_RND)
		seq_printf(seq, "MACDST_RND  ");

	seq_puts(seq, "\n");

	sa = pkt_dev->started_at;
	stopped = pkt_dev->stopped_at;
	if (pkt_dev->running)
		stopped = now;	/* not really stopped, more like last-running-at */

	seq_printf(seq,
		   "Current:\n     pkts-sofar: %llu  errors: %llu\n     started: %lluus  stopped: %lluus idle: %lluus\n",
		   (unsigned long long)pkt_dev->sofar,
		   (unsigned long long)pkt_dev->errors, (unsigned long long)sa,
		   (unsigned long long)stopped,
		   (unsigned long long)pkt_dev->idle_acc);

	seq_printf(seq,
		   "     seq_num: %d  cur_dst_mac_offset: %d  cur_src_mac_offset: %d\n",
		   pkt_dev->seq_num, pkt_dev->cur_dst_mac_offset,
		   pkt_dev->cur_src_mac_offset);

	if (pkt_dev->flags & F_IPV6) {
		char b1[128], b2[128];
		fmt_ip6(b1, pkt_dev->cur_in6_daddr.s6_addr);
		fmt_ip6(b2, pkt_dev->cur_in6_saddr.s6_addr);
		seq_printf(seq, "     cur_saddr: %s  cur_daddr: %s\n", b2, b1);
	} else
		seq_printf(seq, "     cur_saddr: 0x%x  cur_daddr: 0x%x\n",
			   pkt_dev->cur_saddr, pkt_dev->cur_daddr);

	seq_printf(seq, "     cur_udp_dst: %d  cur_udp_src: %d\n",
		   pkt_dev->cur_udp_dst, pkt_dev->cur_udp_src);

	seq_printf(seq, "     flows: %u\n", pkt_dev->nflows);

	if (pkt_dev->result[0])
		seq_printf(seq, "Result: %s\n", pkt_dev->result);
	else
		seq_printf(seq, "Result: Idle\n");

	return 0;
}

static int count_trail_chars(const char __user * user_buffer,
			     unsigned int maxlen)
{
	int i;

	for (i = 0; i < maxlen; i++) {
		char c;
		if (get_user(c, &user_buffer[i]))
			return -EFAULT;
		switch (c) {
		case '\"':
		case '\n':
		case '\r':
		case '\t':
		case ' ':
		case '=':
			break;
		default:
			goto done;
		};
	}
done:
	return i;
}

static unsigned long num_arg(const char __user * user_buffer,
			     unsigned long maxlen, unsigned long *num)
{
	int i = 0;
	*num = 0;

	for (; i < maxlen; i++) {
		char c;
		if (get_user(c, &user_buffer[i]))
			return -EFAULT;
		if ((c >= '0') && (c <= '9')) {
			*num *= 10;
			*num += c - '0';
		} else
			break;
	}
	return i;
}

static int strn_len(const char __user * user_buffer, unsigned int maxlen)
{
	int i = 0;

	for (; i < maxlen; i++) {
		char c;
		if (get_user(c, &user_buffer[i]))
			return -EFAULT;
		switch (c) {
		case '\"':
		case '\n':
		case '\r':
		case '\t':
		case ' ':
			goto done_str;
			break;
		default:
			break;
		};
	}
done_str:
	return i;
}

static ssize_t pktgen_if_write(struct file *file,
			       const char __user * user_buffer, size_t count,
			       loff_t * offset)
{
	struct seq_file *seq = (struct seq_file *)file->private_data;
	struct pktgen_dev *pkt_dev = seq->private;
	int i = 0, max, len;
	char name[16], valstr[32];
	unsigned long value = 0;
	char *pg_result = NULL;
	int tmp = 0;
	char buf[128];

	pg_result = &(pkt_dev->result[0]);

	if (count < 1) {
		printk("pktgen: wrong command format\n");
		return -EINVAL;
	}

	max = count - i;
	tmp = count_trail_chars(&user_buffer[i], max);
	if (tmp < 0) {
		printk("pktgen: illegal format\n");
		return tmp;
	}
	i += tmp;

	/* Read variable name */

	len = strn_len(&user_buffer[i], sizeof(name) - 1);
	if (len < 0) {
		return len;
	}
	memset(name, 0, sizeof(name));
	if (copy_from_user(name, &user_buffer[i], len))
		return -EFAULT;
	i += len;

	max = count - i;
	len = count_trail_chars(&user_buffer[i], max);
	if (len < 0)
		return len;

	i += len;

	if (debug) {
		char tb[count + 1];
		if (copy_from_user(tb, user_buffer, count))
			return -EFAULT;
		tb[count] = 0;
		printk("pktgen: %s,%lu  buffer -:%s:-\n", name,
		       (unsigned long)count, tb);
	}

	if (!strcmp(name, "min_pkt_size")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value < 14 + 20 + 8)
			value = 14 + 20 + 8;
		if (value != pkt_dev->min_pkt_size) {
			pkt_dev->min_pkt_size = value;
			pkt_dev->cur_pkt_size = value;
		}
		sprintf(pg_result, "OK: min_pkt_size=%u",
			pkt_dev->min_pkt_size);
		return count;
	}

	if (!strcmp(name, "max_pkt_size")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value < 14 + 20 + 8)
			value = 14 + 20 + 8;
		if (value != pkt_dev->max_pkt_size) {
			pkt_dev->max_pkt_size = value;
			pkt_dev->cur_pkt_size = value;
		}
		sprintf(pg_result, "OK: max_pkt_size=%u",
			pkt_dev->max_pkt_size);
		return count;
	}

	/* Shortcut for min = max */

	if (!strcmp(name, "pkt_size")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value < 14 + 20 + 8)
			value = 14 + 20 + 8;
		if (value != pkt_dev->min_pkt_size) {
			pkt_dev->min_pkt_size = value;
			pkt_dev->max_pkt_size = value;
			pkt_dev->cur_pkt_size = value;
		}
		sprintf(pg_result, "OK: pkt_size=%u", pkt_dev->min_pkt_size);
		return count;
	}

	if (!strcmp(name, "debug")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		debug = value;
		sprintf(pg_result, "OK: debug=%u", debug);
		return count;
	}

	if (!strcmp(name, "frags")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		pkt_dev->nfrags = value;
		sprintf(pg_result, "OK: frags=%u", pkt_dev->nfrags);
		return count;
	}
	if (!strcmp(name, "delay")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value == 0x7FFFFFFF) {
			pkt_dev->delay_us = 0x7FFFFFFF;
			pkt_dev->delay_ns = 0;
		} else {
			pkt_dev->delay_us = value / 1000;
			pkt_dev->delay_ns = value % 1000;
		}
		sprintf(pg_result, "OK: delay=%u",
			1000 * pkt_dev->delay_us + pkt_dev->delay_ns);
		return count;
	}
	if (!strcmp(name, "udp_src_min")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value != pkt_dev->udp_src_min) {
			pkt_dev->udp_src_min = value;
			pkt_dev->cur_udp_src = value;
		}
		sprintf(pg_result, "OK: udp_src_min=%u", pkt_dev->udp_src_min);
		return count;
	}
	if (!strcmp(name, "udp_dst_min")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value != pkt_dev->udp_dst_min) {
			pkt_dev->udp_dst_min = value;
			pkt_dev->cur_udp_dst = value;
		}
		sprintf(pg_result, "OK: udp_dst_min=%u", pkt_dev->udp_dst_min);
		return count;
	}
	if (!strcmp(name, "udp_src_max")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value != pkt_dev->udp_src_max) {
			pkt_dev->udp_src_max = value;
			pkt_dev->cur_udp_src = value;
		}
		sprintf(pg_result, "OK: udp_src_max=%u", pkt_dev->udp_src_max);
		return count;
	}
	if (!strcmp(name, "udp_dst_max")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value != pkt_dev->udp_dst_max) {
			pkt_dev->udp_dst_max = value;
			pkt_dev->cur_udp_dst = value;
		}
		sprintf(pg_result, "OK: udp_dst_max=%u", pkt_dev->udp_dst_max);
		return count;
	}
	if (!strcmp(name, "clone_skb")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		pkt_dev->clone_skb = value;

		sprintf(pg_result, "OK: clone_skb=%d", pkt_dev->clone_skb);
		return count;
	}
	if (!strcmp(name, "count")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		pkt_dev->count = value;
		sprintf(pg_result, "OK: count=%llu",
			(unsigned long long)pkt_dev->count);
		return count;
	}
	if (!strcmp(name, "src_mac_count")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (pkt_dev->src_mac_count != value) {
			pkt_dev->src_mac_count = value;
			pkt_dev->cur_src_mac_offset = 0;
		}
		sprintf(pg_result, "OK: src_mac_count=%d",
			pkt_dev->src_mac_count);
		return count;
	}
	if (!strcmp(name, "dst_mac_count")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (pkt_dev->dst_mac_count != value) {
			pkt_dev->dst_mac_count = value;
			pkt_dev->cur_dst_mac_offset = 0;
		}
		sprintf(pg_result, "OK: dst_mac_count=%d",
			pkt_dev->dst_mac_count);
		return count;
	}
	if (!strcmp(name, "flag")) {
		char f[32];
		memset(f, 0, 32);
		len = strn_len(&user_buffer[i], sizeof(f) - 1);
		if (len < 0) {
			return len;
		}
		if (copy_from_user(f, &user_buffer[i], len))
			return -EFAULT;
		i += len;
		if (strcmp(f, "IPSRC_RND") == 0)
			pkt_dev->flags |= F_IPSRC_RND;

		else if (strcmp(f, "!IPSRC_RND") == 0)
			pkt_dev->flags &= ~F_IPSRC_RND;

		else if (strcmp(f, "TXSIZE_RND") == 0)
			pkt_dev->flags |= F_TXSIZE_RND;

		else if (strcmp(f, "!TXSIZE_RND") == 0)
			pkt_dev->flags &= ~F_TXSIZE_RND;

		else if (strcmp(f, "IPDST_RND") == 0)
			pkt_dev->flags |= F_IPDST_RND;

		else if (strcmp(f, "!IPDST_RND") == 0)
			pkt_dev->flags &= ~F_IPDST_RND;

		else if (strcmp(f, "UDPSRC_RND") == 0)
			pkt_dev->flags |= F_UDPSRC_RND;

		else if (strcmp(f, "!UDPSRC_RND") == 0)
			pkt_dev->flags &= ~F_UDPSRC_RND;

		else if (strcmp(f, "UDPDST_RND") == 0)
			pkt_dev->flags |= F_UDPDST_RND;

		else if (strcmp(f, "!UDPDST_RND") == 0)
			pkt_dev->flags &= ~F_UDPDST_RND;

		else if (strcmp(f, "MACSRC_RND") == 0)
			pkt_dev->flags |= F_MACSRC_RND;

		else if (strcmp(f, "!MACSRC_RND") == 0)
			pkt_dev->flags &= ~F_MACSRC_RND;

		else if (strcmp(f, "MACDST_RND") == 0)
			pkt_dev->flags |= F_MACDST_RND;

		else if (strcmp(f, "!MACDST_RND") == 0)
			pkt_dev->flags &= ~F_MACDST_RND;

		else {
			sprintf(pg_result,
				"Flag -:%s:- unknown\nAvailable flags, (prepend ! to un-set flag):\n%s",
				f,
				"IPSRC_RND, IPDST_RND, TXSIZE_RND, UDPSRC_RND, UDPDST_RND, MACSRC_RND, MACDST_RND\n");
			return count;
		}
		sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
		return count;
	}
	if (!strcmp(name, "dst_min") || !strcmp(name, "dst")) {
		len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_min) - 1);
		if (len < 0) {
			return len;
		}

		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;
		buf[len] = 0;
		if (strcmp(buf, pkt_dev->dst_min) != 0) {
			memset(pkt_dev->dst_min, 0, sizeof(pkt_dev->dst_min));
			strncpy(pkt_dev->dst_min, buf, len);
			pkt_dev->daddr_min = in_aton(pkt_dev->dst_min);
			pkt_dev->cur_daddr = pkt_dev->daddr_min;
		}
		if (debug)
			printk("pktgen: dst_min set to: %s\n",
			       pkt_dev->dst_min);
		i += len;
		sprintf(pg_result, "OK: dst_min=%s", pkt_dev->dst_min);
		return count;
	}
	if (!strcmp(name, "dst_max")) {
		len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_max) - 1);
		if (len < 0) {
			return len;
		}

		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;

		buf[len] = 0;
		if (strcmp(buf, pkt_dev->dst_max) != 0) {
			memset(pkt_dev->dst_max, 0, sizeof(pkt_dev->dst_max));
			strncpy(pkt_dev->dst_max, buf, len);
			pkt_dev->daddr_max = in_aton(pkt_dev->dst_max);
			pkt_dev->cur_daddr = pkt_dev->daddr_max;
		}
		if (debug)
			printk("pktgen: dst_max set to: %s\n",
			       pkt_dev->dst_max);
		i += len;
		sprintf(pg_result, "OK: dst_max=%s", pkt_dev->dst_max);
		return count;
	}
	if (!strcmp(name, "dst6")) {
		len = strn_len(&user_buffer[i], sizeof(buf) - 1);
		if (len < 0)
			return len;

		pkt_dev->flags |= F_IPV6;

		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;
		buf[len] = 0;

		scan_ip6(buf, pkt_dev->in6_daddr.s6_addr);
		fmt_ip6(buf, pkt_dev->in6_daddr.s6_addr);

		ipv6_addr_copy(&pkt_dev->cur_in6_daddr, &pkt_dev->in6_daddr);

		if (debug)
			printk("pktgen: dst6 set to: %s\n", buf);

		i += len;
		sprintf(pg_result, "OK: dst6=%s", buf);
		return count;
	}
	if (!strcmp(name, "dst6_min")) {
		len = strn_len(&user_buffer[i], sizeof(buf) - 1);
		if (len < 0)
			return len;

		pkt_dev->flags |= F_IPV6;

		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;
		buf[len] = 0;

		scan_ip6(buf, pkt_dev->min_in6_daddr.s6_addr);
		fmt_ip6(buf, pkt_dev->min_in6_daddr.s6_addr);

		ipv6_addr_copy(&pkt_dev->cur_in6_daddr,
			       &pkt_dev->min_in6_daddr);
		if (debug)
			printk("pktgen: dst6_min set to: %s\n", buf);

		i += len;
		sprintf(pg_result, "OK: dst6_min=%s", buf);
		return count;
	}
	if (!strcmp(name, "dst6_max")) {
		len = strn_len(&user_buffer[i], sizeof(buf) - 1);
		if (len < 0)
			return len;

		pkt_dev->flags |= F_IPV6;

		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;
		buf[len] = 0;

		scan_ip6(buf, pkt_dev->max_in6_daddr.s6_addr);
		fmt_ip6(buf, pkt_dev->max_in6_daddr.s6_addr);

		if (debug)
			printk("pktgen: dst6_max set to: %s\n", buf);

		i += len;
		sprintf(pg_result, "OK: dst6_max=%s", buf);
		return count;
	}
	if (!strcmp(name, "src6")) {
		len = strn_len(&user_buffer[i], sizeof(buf) - 1);
		if (len < 0)
			return len;

		pkt_dev->flags |= F_IPV6;

		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;
		buf[len] = 0;

		scan_ip6(buf, pkt_dev->in6_saddr.s6_addr);
		fmt_ip6(buf, pkt_dev->in6_saddr.s6_addr);

		ipv6_addr_copy(&pkt_dev->cur_in6_saddr, &pkt_dev->in6_saddr);

		if (debug)
			printk("pktgen: src6 set to: %s\n", buf);

		i += len;
		sprintf(pg_result, "OK: src6=%s", buf);
		return count;
	}
	if (!strcmp(name, "src_min")) {
		len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_min) - 1);
		if (len < 0) {
			return len;
		}
		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;
		buf[len] = 0;
		if (strcmp(buf, pkt_dev->src_min) != 0) {
			memset(pkt_dev->src_min, 0, sizeof(pkt_dev->src_min));
			strncpy(pkt_dev->src_min, buf, len);
			pkt_dev->saddr_min = in_aton(pkt_dev->src_min);
			pkt_dev->cur_saddr = pkt_dev->saddr_min;
		}
		if (debug)
			printk("pktgen: src_min set to: %s\n",
			       pkt_dev->src_min);
		i += len;
		sprintf(pg_result, "OK: src_min=%s", pkt_dev->src_min);
		return count;
	}
	if (!strcmp(name, "src_max")) {
		len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_max) - 1);
		if (len < 0) {
			return len;
		}
		if (copy_from_user(buf, &user_buffer[i], len))
			return -EFAULT;
		buf[len] = 0;
		if (strcmp(buf, pkt_dev->src_max) != 0) {
			memset(pkt_dev->src_max, 0, sizeof(pkt_dev->src_max));
			strncpy(pkt_dev->src_max, buf, len);
			pkt_dev->saddr_max = in_aton(pkt_dev->src_max);
			pkt_dev->cur_saddr = pkt_dev->saddr_max;
		}
		if (debug)
			printk("pktgen: src_max set to: %s\n",
			       pkt_dev->src_max);
		i += len;
		sprintf(pg_result, "OK: src_max=%s", pkt_dev->src_max);
		return count;
	}
	if (!strcmp(name, "dst_mac")) {
		char *v = valstr;
		unsigned char old_dmac[ETH_ALEN];
		unsigned char *m = pkt_dev->dst_mac;
		memcpy(old_dmac, pkt_dev->dst_mac, ETH_ALEN);

		len = strn_len(&user_buffer[i], sizeof(valstr) - 1);
		if (len < 0) {
			return len;
		}
		memset(valstr, 0, sizeof(valstr));
		if (copy_from_user(valstr, &user_buffer[i], len))
			return -EFAULT;
		i += len;

		for (*m = 0; *v && m < pkt_dev->dst_mac + 6; v++) {
			if (*v >= '0' && *v <= '9') {
				*m *= 16;
				*m += *v - '0';
			}
			if (*v >= 'A' && *v <= 'F') {
				*m *= 16;
				*m += *v - 'A' + 10;
			}
			if (*v >= 'a' && *v <= 'f') {
				*m *= 16;
				*m += *v - 'a' + 10;
			}
			if (*v == ':') {
				m++;
				*m = 0;
			}
		}

		/* Set up Dest MAC */
		if (compare_ether_addr(old_dmac, pkt_dev->dst_mac))
			memcpy(&(pkt_dev->hh[0]), pkt_dev->dst_mac, ETH_ALEN);

		sprintf(pg_result, "OK: dstmac");
		return count;
	}
	if (!strcmp(name, "src_mac")) {
		char *v = valstr;
		unsigned char *m = pkt_dev->src_mac;

		len = strn_len(&user_buffer[i], sizeof(valstr) - 1);
		if (len < 0) {
			return len;
		}
		memset(valstr, 0, sizeof(valstr));
		if (copy_from_user(valstr, &user_buffer[i], len))
			return -EFAULT;
		i += len;

		for (*m = 0; *v && m < pkt_dev->src_mac + 6; v++) {
			if (*v >= '0' && *v <= '9') {
				*m *= 16;
				*m += *v - '0';
			}
			if (*v >= 'A' && *v <= 'F') {
				*m *= 16;
				*m += *v - 'A' + 10;
			}
			if (*v >= 'a' && *v <= 'f') {
				*m *= 16;
				*m += *v - 'a' + 10;
			}
			if (*v == ':') {
				m++;
				*m = 0;
			}
		}

		sprintf(pg_result, "OK: srcmac");
		return count;
	}

	if (!strcmp(name, "clear_counters")) {
		pktgen_clear_counters(pkt_dev);
		sprintf(pg_result, "OK: Clearing counters.\n");
		return count;
	}

	if (!strcmp(name, "flows")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		if (value > MAX_CFLOWS)
			value = MAX_CFLOWS;

		pkt_dev->cflows = value;
		sprintf(pg_result, "OK: flows=%u", pkt_dev->cflows);
		return count;
	}

	if (!strcmp(name, "flowlen")) {
		len = num_arg(&user_buffer[i], 10, &value);
		if (len < 0) {
			return len;
		}
		i += len;
		pkt_dev->lflow = value;
		sprintf(pg_result, "OK: flowlen=%u", pkt_dev->lflow);
		return count;
	}

	sprintf(pkt_dev->result, "No such parameter \"%s\"", name);
	return -EINVAL;
}

static int pktgen_if_open(struct inode *inode, struct file *file)
{
	return single_open(file, pktgen_if_show, PDE(inode)->data);
}

static struct file_operations pktgen_if_fops = {
	.owner   = THIS_MODULE,
	.open    = pktgen_if_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.write   = pktgen_if_write,
	.release = single_release,
};

static int pktgen_thread_show(struct seq_file *seq, void *v)
{
	struct pktgen_thread *t = seq->private;
	struct pktgen_dev *pkt_dev;

	BUG_ON(!t);

	seq_printf(seq, "Name: %s  max_before_softirq: %d\n",
		   t->name, t->max_before_softirq);

	seq_printf(seq, "Running: ");

	if_lock(t);
	list_for_each_entry(pkt_dev, &t->if_list, list)
		if (pkt_dev->running)
			seq_printf(seq, "%s ", pkt_dev->ifname);

	seq_printf(seq, "\nStopped: ");

	list_for_each_entry(pkt_dev, &t->if_list, list)
		if (!pkt_dev->running)
			seq_printf(seq, "%s ", pkt_dev->ifname);

	if (t->result[0])
		seq_printf(seq, "\nResult: %s\n", t->result);
	else
		seq_printf(seq, "\nResult: NA\n");

	if_unlock(t);

	return 0;
}

static ssize_t pktgen_thread_write(struct file *file,
				   const char __user * user_buffer,
				   size_t count, loff_t * offset)
{
	struct seq_file *seq = (struct seq_file *)file->private_data;
	struct pktgen_thread *t = seq->private;
	int i = 0, max, len, ret;
	char name[40];
	char *pg_result;
	unsigned long value = 0;

	if (count < 1) {
		//      sprintf(pg_result, "Wrong command format");
		return -EINVAL;
	}

	max = count - i;
	len = count_trail_chars(&user_buffer[i], max);
	if (len < 0)
		return len;

	i += len;

	/* Read variable name */

	len = strn_len(&user_buffer[i], sizeof(name) - 1);
	if (len < 0)
		return len;

	memset(name, 0, sizeof(name));
	if (copy_from_user(name, &user_buffer[i], len))
		return -EFAULT;
	i += len;

	max = count - i;
	len = count_trail_chars(&user_buffer[i], max);
	if (len < 0)
		return len;

	i += len;

	if (debug)
		printk("pktgen: t=%s, count=%lu\n", name, (unsigned long)count);

	if (!t) {
		printk("pktgen: ERROR: No thread\n");
		ret = -EINVAL;
		goto out;
	}

	pg_result = &(t->result[0]);

	if (!strcmp(name, "add_device")) {
		char f[32];
		memset(f, 0, 32);
		len = strn_len(&user_buffer[i], sizeof(f) - 1);
		if (len < 0) {
			ret = len;
			goto out;
		}
		if (copy_from_user(f, &user_buffer[i], len))
			return -EFAULT;
		i += len;
		mutex_lock(&pktgen_thread_lock);
		pktgen_add_device(t, f);
		mutex_unlock(&pktgen_thread_lock);
		ret = count;
		sprintf(pg_result, "OK: add_device=%s", f);
		goto out;
	}

	if (!strcmp(name, "rem_device_all")) {
		mutex_lock(&pktgen_thread_lock);
		t->control |= T_REMDEVALL;
		mutex_unlock(&pktgen_thread_lock);
		schedule_timeout_interruptible(msecs_to_jiffies(125));	/* Propagate thread->control  */
		ret = count;
		sprintf(pg_result, "OK: rem_device_all");
		goto out;
	}

	if (!strcmp(name, "max_before_softirq")) {
		len = num_arg(&user_buffer[i], 10, &value);
		mutex_lock(&pktgen_thread_lock);
		t->max_before_softirq = value;
		mutex_unlock(&pktgen_thread_lock);
		ret = count;
		sprintf(pg_result, "OK: max_before_softirq=%lu", value);
		goto out;
	}

	ret = -EINVAL;
out:
	return ret;
}

static int pktgen_thread_open(struct inode *inode, struct file *file)
{
	return single_open(file, pktgen_thread_show, PDE(inode)->data);
}

static struct file_operations pktgen_thread_fops = {
	.owner   = THIS_MODULE,
	.open    = pktgen_thread_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.write   = pktgen_thread_write,
	.release = single_release,
};

/* Think find or remove for NN */
static struct pktgen_dev *__pktgen_NN_threads(const char *ifname, int remove)
{
	struct pktgen_thread *t;
	struct pktgen_dev *pkt_dev = NULL;

	list_for_each_entry(t, &pktgen_threads, th_list) {
		pkt_dev = pktgen_find_dev(t, ifname);
		if (pkt_dev) {
			if (remove) {
				if_lock(t);
				pkt_dev->removal_mark = 1;
				t->control |= T_REMDEV;
				if_unlock(t);
			}
			break;
		}
	}
	return pkt_dev;
}

/*
 * mark a device for removal
 */
static int pktgen_mark_device(const char *ifname)
{
	struct pktgen_dev *pkt_dev = NULL;
	const int max_tries = 10, msec_per_try = 125;
	int i = 0;
	int ret = 0;

	mutex_lock(&pktgen_thread_lock);
	PG_DEBUG(printk("pktgen: pktgen_mark_device marking %s for removal\n",
			ifname));

	while (1) {

		pkt_dev = __pktgen_NN_threads(ifname, REMOVE);
		if (pkt_dev == NULL)
			break;	/* success */

		mutex_unlock(&pktgen_thread_lock);
		PG_DEBUG(printk("pktgen: pktgen_mark_device waiting for %s "
				"to disappear....\n", ifname));
		schedule_timeout_interruptible(msecs_to_jiffies(msec_per_try));
		mutex_lock(&pktgen_thread_lock);

		if (++i >= max_tries) {
			printk("pktgen_mark_device: timed out after waiting "
			       "%d msec for device %s to be removed\n",
			       msec_per_try * i, ifname);
			ret = 1;
			break;
		}

	}

	mutex_unlock(&pktgen_thread_lock);

	return ret;
}

static int pktgen_device_event(struct notifier_block *unused,
			       unsigned long event, void *ptr)
{
	struct net_device *dev = (struct net_device *)(ptr);

	/* It is OK that we do not hold the group lock right now,
	 * as we run under the RTNL lock.
	 */

	switch (event) {
	case NETDEV_CHANGEADDR:
	case NETDEV_GOING_DOWN:
	case NETDEV_DOWN:
	case NETDEV_UP:
		/* Ignore for now */
		break;

	case NETDEV_UNREGISTER:
		pktgen_mark_device(dev->name);
		break;
	};

	return NOTIFY_DONE;
}

/* Associate pktgen_dev with a device. */

static struct net_device *pktgen_setup_dev(struct pktgen_dev *pkt_dev)
{
	struct net_device *odev;

	/* Clean old setups */

	if (pkt_dev->odev) {
		dev_put(pkt_dev->odev);
		pkt_dev->odev = NULL;
	}

	odev = dev_get_by_name(pkt_dev->ifname);

	if (!odev) {
		printk("pktgen: no such netdevice: \"%s\"\n", pkt_dev->ifname);
		goto out;
	}
	if (odev->type != ARPHRD_ETHER) {
		printk("pktgen: not an ethernet device: \"%s\"\n",
		       pkt_dev->ifname);
		goto out_put;
	}
	if (!netif_running(odev)) {
		printk("pktgen: device is down: \"%s\"\n", pkt_dev->ifname);
		goto out_put;
	}
	pkt_dev->odev = odev;

	return pkt_dev->odev;

out_put:
	dev_put(odev);
out:
	return NULL;

}

/* Read pkt_dev from the interface and set up internal pktgen_dev
 * structure to have the right information to create/send packets
 */
static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
{
	/* Try once more, just in case it works now. */
	if (!pkt_dev->odev)
		pktgen_setup_dev(pkt_dev);

	if (!pkt_dev->odev) {
		printk("pktgen: ERROR: pkt_dev->odev == NULL in setup_inject.\n");
		sprintf(pkt_dev->result,
			"ERROR: pkt_dev->odev == NULL in setup_inject.\n");
		return;
	}

	/* Default to the interface's mac if not explicitly set. */

	if (is_zero_ether_addr(pkt_dev->src_mac))
		memcpy(&(pkt_dev->hh[6]), pkt_dev->odev->dev_addr, ETH_ALEN);

	/* Set up Dest MAC */
	memcpy(&(pkt_dev->hh[0]), pkt_dev->dst_mac, ETH_ALEN);

	/* Set up pkt size */
	pkt_dev->cur_pkt_size = pkt_dev->min_pkt_size;

	if (pkt_dev->flags & F_IPV6) {
		/*
		 * Skip this automatic address setting until locks or functions 
		 * gets exported
		 */

#ifdef NOTNOW
		int i, set = 0, err = 1;
		struct inet6_dev *idev;

		for (i = 0; i < IN6_ADDR_HSIZE; i++)
			if (pkt_dev->cur_in6_saddr.s6_addr[i]) {
				set = 1;
				break;
			}

		if (!set) {

			/*
			 * Use linklevel address if unconfigured.
			 *
			 * use ipv6_get_lladdr if/when it's get exported
			 */

			read_lock(&addrconf_lock);
			if ((idev = __in6_dev_get(pkt_dev->odev)) != NULL) {
				struct inet6_ifaddr *ifp;

				read_lock_bh(&idev->lock);
				for (ifp = idev->addr_list; ifp;
				     ifp = ifp->if_next) {
					if (ifp->scope == IFA_LINK
					    && !(ifp->
						 flags & IFA_F_TENTATIVE)) {
						ipv6_addr_copy(&pkt_dev->
							       cur_in6_saddr,
							       &ifp->addr);
						err = 0;
						break;
					}
				}
				read_unlock_bh(&idev->lock);
			}
			read_unlock(&addrconf_lock);
			if (err)
				printk("pktgen: ERROR: IPv6 link address not availble.\n");
		}
#endif
	} else {
		pkt_dev->saddr_min = 0;
		pkt_dev->saddr_max = 0;
		if (strlen(pkt_dev->src_min) == 0) {

			struct in_device *in_dev;

			rcu_read_lock();
			in_dev = __in_dev_get_rcu(pkt_dev->odev);
			if (in_dev) {
				if (in_dev->ifa_list) {
					pkt_dev->saddr_min =
					    in_dev->ifa_list->ifa_address;
					pkt_dev->saddr_max = pkt_dev->saddr_min;
				}
			}
			rcu_read_unlock();
		} else {
			pkt_dev->saddr_min = in_aton(pkt_dev->src_min);
			pkt_dev->saddr_max = in_aton(pkt_dev->src_max);
		}

		pkt_dev->daddr_min = in_aton(pkt_dev->dst_min);
		pkt_dev->daddr_max = in_aton(pkt_dev->dst_max);
	}
	/* Initialize current values. */
	pkt_dev->cur_dst_mac_offset = 0;
	pkt_dev->cur_src_mac_offset = 0;
	pkt_dev->cur_saddr = pkt_dev->saddr_min;
	pkt_dev->cur_daddr = pkt_dev->daddr_min;
	pkt_dev->cur_udp_dst = pkt_dev->udp_dst_min;
	pkt_dev->cur_udp_src = pkt_dev->udp_src_min;
	pkt_dev->nflows = 0;
}

static void spin(struct pktgen_dev *pkt_dev, __u64 spin_until_us)
{
	__u64 start;
	__u64 now;

	start = now = getCurUs();
	printk(KERN_INFO "sleeping for %d\n", (int)(spin_until_us - now));
	while (now < spin_until_us) {
		/* TODO: optimize sleeping behavior */
		if (spin_until_us - now > jiffies_to_usecs(1) + 1)
			schedule_timeout_interruptible(1);
		else if (spin_until_us - now > 100) {
			do_softirq();
			if (!pkt_dev->running)
				return;
			if (need_resched())
				schedule();
		}

		now = getCurUs();
	}

	pkt_dev->idle_acc += now - start;
}

/* Increment/randomize headers according to flags and current values
 * for IP src/dest, UDP src/dst port, MAC-Addr src/dst
 */
static void mod_cur_headers(struct pktgen_dev *pkt_dev)
{
	__u32 imn;
	__u32 imx;
	int flow = 0;

	if (pkt_dev->cflows) {
		flow = pktgen_random() % pkt_dev->cflows;

		if (pkt_dev->flows[flow].count > pkt_dev->lflow)
			pkt_dev->flows[flow].count = 0;
	}

	/*  Deal with source MAC */
	if (pkt_dev->src_mac_count > 1) {
		__u32 mc;
		__u32 tmp;

		if (pkt_dev->flags & F_MACSRC_RND)
			mc = pktgen_random() % (pkt_dev->src_mac_count);
		else {
			mc = pkt_dev->cur_src_mac_offset++;
			if (pkt_dev->cur_src_mac_offset >
			    pkt_dev->src_mac_count)
				pkt_dev->cur_src_mac_offset = 0;
		}

		tmp = pkt_dev->src_mac[5] + (mc & 0xFF);
		pkt_dev->hh[11] = tmp;
		tmp = (pkt_dev->src_mac[4] + ((mc >> 8) & 0xFF) + (tmp >> 8));
		pkt_dev->hh[10] = tmp;
		tmp = (pkt_dev->src_mac[3] + ((mc >> 16) & 0xFF) + (tmp >> 8));
		pkt_dev->hh[9] = tmp;
		tmp = (pkt_dev->src_mac[2] + ((mc >> 24) & 0xFF) + (tmp >> 8));
		pkt_dev->hh[8] = tmp;
		tmp = (pkt_dev->src_mac[1] + (tmp >> 8));
		pkt_dev->hh[7] = tmp;
	}

	/*  Deal with Destination MAC */
	if (pkt_dev->dst_mac_count > 1) {
		__u32 mc;
		__u32 tmp;

		if (pkt_dev->flags & F_MACDST_RND)
			mc = pktgen_random() % (pkt_dev->dst_mac_count);

		else {
			mc = pkt_dev->cur_dst_mac_offset++;
			if (pkt_dev->cur_dst_mac_offset >
			    pkt_dev->dst_mac_count) {
				pkt_dev->cur_dst_mac_offset = 0;
			}
		}

		tmp = pkt_dev->dst_mac[5] + (mc & 0xFF);
		pkt_dev->hh[5] = tmp;
		tmp = (pkt_dev->dst_mac[4] + ((mc >> 8) & 0xFF) + (tmp >> 8));
		pkt_dev->hh[4] = tmp;
		tmp = (pkt_dev->dst_mac[3] + ((mc >> 16) & 0xFF) + (tmp >> 8));
		pkt_dev->hh[3] = tmp;
		tmp = (pkt_dev->dst_mac[2] + ((mc >> 24) & 0xFF) + (tmp >> 8));
		pkt_dev->hh[2] = tmp;
		tmp = (pkt_dev->dst_mac[1] + (tmp >> 8));
		pkt_dev->hh[1] = tmp;
	}

	if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
		if (pkt_dev->flags & F_UDPSRC_RND)
			pkt_dev->cur_udp_src =
			    ((pktgen_random() %
			      (pkt_dev->udp_src_max - pkt_dev->udp_src_min)) +
			     pkt_dev->udp_src_min);

		else {
			pkt_dev->cur_udp_src++;
			if (pkt_dev->cur_udp_src >= pkt_dev->udp_src_max)
				pkt_dev->cur_udp_src = pkt_dev->udp_src_min;
		}
	}

	if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
		if (pkt_dev->flags & F_UDPDST_RND) {
			pkt_dev->cur_udp_dst =
			    ((pktgen_random() %
			      (pkt_dev->udp_dst_max - pkt_dev->udp_dst_min)) +
			     pkt_dev->udp_dst_min);
		} else {
			pkt_dev->cur_udp_dst++;
			if (pkt_dev->cur_udp_dst >= pkt_dev->udp_dst_max)
				pkt_dev->cur_udp_dst = pkt_dev->udp_dst_min;
		}
	}

	if (!(pkt_dev->flags & F_IPV6)) {

		if ((imn = ntohl(pkt_dev->saddr_min)) < (imx =
							 ntohl(pkt_dev->
							       saddr_max))) {
			__u32 t;
			if (pkt_dev->flags & F_IPSRC_RND)
				t = ((pktgen_random() % (imx - imn)) + imn);
			else {
				t = ntohl(pkt_dev->cur_saddr);
				t++;
				if (t > imx) {
					t = imn;
				}
			}
			pkt_dev->cur_saddr = htonl(t);
		}

		if (pkt_dev->cflows && pkt_dev->flows[flow].count != 0) {
			pkt_dev->cur_daddr = pkt_dev->flows[flow].cur_daddr;
		} else {

			if ((imn = ntohl(pkt_dev->daddr_min)) < (imx =
								 ntohl(pkt_dev->
								       daddr_max)))
			{
				__u32 t;
				if (pkt_dev->flags & F_IPDST_RND) {

					t = ((pktgen_random() % (imx - imn)) +
					     imn);
					t = htonl(t);

					while (LOOPBACK(t) || MULTICAST(t)
					       || BADCLASS(t) || ZERONET(t)
					       || LOCAL_MCAST(t)) {
						t = ((pktgen_random() %
						      (imx - imn)) + imn);
						t = htonl(t);
					}
					pkt_dev->cur_daddr = t;
				}

				else {
					t = ntohl(pkt_dev->cur_daddr);
					t++;
					if (t > imx) {
						t = imn;
					}
					pkt_dev->cur_daddr = htonl(t);
				}
			}
			if (pkt_dev->cflows) {
				pkt_dev->flows[flow].cur_daddr =
				    pkt_dev->cur_daddr;
				pkt_dev->nflows++;
			}
		}
	} else {		/* IPV6 * */

		if (pkt_dev->min_in6_daddr.s6_addr32[0] == 0 &&
		    pkt_dev->min_in6_daddr.s6_addr32[1] == 0 &&
		    pkt_dev->min_in6_daddr.s6_addr32[2] == 0 &&
		    pkt_dev->min_in6_daddr.s6_addr32[3] == 0) ;
		else {
			int i;

			/* Only random destinations yet */

			for (i = 0; i < 4; i++) {
				pkt_dev->cur_in6_daddr.s6_addr32[i] =
				    ((pktgen_random() |
				      pkt_dev->min_in6_daddr.s6_addr32[i]) &
				     pkt_dev->max_in6_daddr.s6_addr32[i]);
			}
		}
	}

	if (pkt_dev->min_pkt_size < pkt_dev->max_pkt_size) {
		__u32 t;
		if (pkt_dev->flags & F_TXSIZE_RND) {
			t = ((pktgen_random() %
			      (pkt_dev->max_pkt_size - pkt_dev->min_pkt_size))
			     + pkt_dev->min_pkt_size);
		} else {
			t = pkt_dev->cur_pkt_size + 1;
			if (t > pkt_dev->max_pkt_size)
				t = pkt_dev->min_pkt_size;
		}
		pkt_dev->cur_pkt_size = t;
	}

	pkt_dev->flows[flow].count++;
}

static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
					struct pktgen_dev *pkt_dev)
{
	struct sk_buff *skb = NULL;
	__u8 *eth;
	struct udphdr *udph;
	int datalen, iplen;
	struct iphdr *iph;
	struct pktgen_hdr *pgh = NULL;

	/* Update any of the values, used when we're incrementing various
	 * fields.
	 */
	mod_cur_headers(pkt_dev);

	datalen = (odev->hard_header_len + 16) & ~0xf;
	skb = alloc_skb(pkt_dev->cur_pkt_size + 64 + datalen, GFP_ATOMIC);
	if (!skb) {
		sprintf(pkt_dev->result, "No memory");
		return NULL;
	}

	skb_reserve(skb, datalen);

	/*  Reserve for ethernet and IP header  */
	eth = (__u8 *) skb_push(skb, 14);
	iph = (struct iphdr *)skb_put(skb, sizeof(struct iphdr));
	udph = (struct udphdr *)skb_put(skb, sizeof(struct udphdr));

	memcpy(eth, pkt_dev->hh, 12);
	*(u16 *) & eth[12] = __constant_htons(ETH_P_IP);

	datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8;	/* Eth + IPh + UDPh */
	if (datalen < sizeof(struct pktgen_hdr))
		datalen = sizeof(struct pktgen_hdr);

	udph->source = htons(pkt_dev->cur_udp_src);
	udph->dest = htons(pkt_dev->cur_udp_dst);
	udph->len = htons(datalen + 8);	/* DATA + udphdr */
	udph->check = 0;	/* No checksum */

	iph->ihl = 5;
	iph->version = 4;
	iph->ttl = 32;
	iph->tos = 0;
	iph->protocol = IPPROTO_UDP;	/* UDP */
	iph->saddr = pkt_dev->cur_saddr;
	iph->daddr = pkt_dev->cur_daddr;
	iph->frag_off = 0;
	iplen = 20 + 8 + datalen;
	iph->tot_len = htons(iplen);
	iph->check = 0;
	iph->check = ip_fast_csum((void *)iph, iph->ihl);
	skb->protocol = __constant_htons(ETH_P_IP);
	skb->mac.raw = ((u8 *) iph) - 14;
	skb->dev = odev;
	skb->pkt_type = PACKET_HOST;

	if (pkt_dev->nfrags <= 0)
		pgh = (struct pktgen_hdr *)skb_put(skb, datalen);
	else {
		int frags = pkt_dev->nfrags;
		int i;

		pgh = (struct pktgen_hdr *)(((char *)(udph)) + 8);

		if (frags > MAX_SKB_FRAGS)
			frags = MAX_SKB_FRAGS;
		if (datalen > frags * PAGE_SIZE) {
			skb_put(skb, datalen - frags * PAGE_SIZE);
			datalen = frags * PAGE_SIZE;
		}

		i = 0;
		while (datalen > 0) {
			struct page *page = alloc_pages(GFP_KERNEL, 0);
			skb_shinfo(skb)->frags[i].page = page;
			skb_shinfo(skb)->frags[i].page_offset = 0;
			skb_shinfo(skb)->frags[i].size =
			    (datalen < PAGE_SIZE ? datalen : PAGE_SIZE);
			datalen -= skb_shinfo(skb)->frags[i].size;
			skb->len += skb_shinfo(skb)->frags[i].size;
			skb->data_len += skb_shinfo(skb)->frags[i].size;
			i++;
			skb_shinfo(skb)->nr_frags = i;
		}

		while (i < frags) {
			int rem;

			if (i == 0)
				break;

			rem = skb_shinfo(skb)->frags[i - 1].size / 2;
			if (rem == 0)
				break;

			skb_shinfo(skb)->frags[i - 1].size -= rem;

			skb_shinfo(skb)->frags[i] =
			    skb_shinfo(skb)->frags[i - 1];
			get_page(skb_shinfo(skb)->frags[i].page);
			skb_shinfo(skb)->frags[i].page =
			    skb_shinfo(skb)->frags[i - 1].page;
			skb_shinfo(skb)->frags[i].page_offset +=
			    skb_shinfo(skb)->frags[i - 1].size;
			skb_shinfo(skb)->frags[i].size = rem;
			i++;
			skb_shinfo(skb)->nr_frags = i;
		}
	}

	/* Stamp the time, and sequence number, convert them to network byte order */

	if (pgh) {
		struct timeval timestamp;

		pgh->pgh_magic = htonl(PKTGEN_MAGIC);
		pgh->seq_num = htonl(pkt_dev->seq_num);

		do_gettimeofday(&timestamp);
		pgh->tv_sec = htonl(timestamp.tv_sec);
		pgh->tv_usec = htonl(timestamp.tv_usec);
	}
	pkt_dev->seq_num++;

	return skb;
}

/*
 * scan_ip6, fmt_ip taken from dietlibc-0.21 
 * Author Felix von Leitner <felix-dietlibc@fefe.de>
 *
 * Slightly modified for kernel. 
 * Should be candidate for net/ipv4/utils.c
 * --ro
 */

static unsigned int scan_ip6(const char *s, char ip[16])
{
	unsigned int i;
	unsigned int len = 0;
	unsigned long u;
	char suffix[16];
	unsigned int prefixlen = 0;
	unsigned int suffixlen = 0;
	__u32 tmp;

	for (i = 0; i < 16; i++)
		ip[i] = 0;

	for (;;) {
		if (*s == ':') {
			len++;
			if (s[1] == ':') {	/* Found "::", skip to part 2 */
				s += 2;
				len++;
				break;
			}
			s++;
		}
		{
			char *tmp;
			u = simple_strtoul(s, &tmp, 16);
			i = tmp - s;
		}

		if (!i)
			return 0;
		if (prefixlen == 12 && s[i] == '.') {

			/* the last 4 bytes may be written as IPv4 address */

			tmp = in_aton(s);
			memcpy((struct in_addr *)(ip + 12), &tmp, sizeof(tmp));
			return i + len;
		}
		ip[prefixlen++] = (u >> 8);
		ip[prefixlen++] = (u & 255);
		s += i;
		len += i;
		if (prefixlen == 16)
			return len;
	}

/* part 2, after "::" */
	for (;;) {
		if (*s == ':') {
			if (suffixlen == 0)
				break;
			s++;
			len++;
		} else if (suffixlen != 0)
			break;
		{
			char *tmp;
			u = simple_strtol(s, &tmp, 16);
			i = tmp - s;
		}
		if (!i) {
			if (*s)
				len--;
			break;
		}
		if (suffixlen + prefixlen <= 12 && s[i] == '.') {
			tmp = in_aton(s);
			memcpy((struct in_addr *)(suffix + suffixlen), &tmp,
			       sizeof(tmp));
			suffixlen += 4;
			len += strlen(s);
			break;
		}
		suffix[suffixlen++] = (u >> 8);
		suffix[suffixlen++] = (u & 255);
		s += i;
		len += i;
		if (prefixlen + suffixlen == 16)
			break;
	}
	for (i = 0; i < suffixlen; i++)
		ip[16 - suffixlen + i] = suffix[i];
	return len;
}

static char tohex(char hexdigit)
{
	return hexdigit > 9 ? hexdigit + 'a' - 10 : hexdigit + '0';
}

static int fmt_xlong(char *s, unsigned int i)
{
	char *bak = s;
	*s = tohex((i >> 12) & 0xf);
	if (s != bak || *s != '0')
		++s;
	*s = tohex((i >> 8) & 0xf);
	if (s != bak || *s != '0')
		++s;
	*s = tohex((i >> 4) & 0xf);
	if (s != bak || *s != '0')
		++s;
	*s = tohex(i & 0xf);
	return s - bak + 1;
}

static unsigned int fmt_ip6(char *s, const char ip[16])
{
	unsigned int len;
	unsigned int i;
	unsigned int temp;
	unsigned int compressing;
	int j;

	len = 0;
	compressing = 0;
	for (j = 0; j < 16; j += 2) {

#ifdef V4MAPPEDPREFIX
		if (j == 12 && !memcmp(ip, V4mappedprefix, 12)) {
			inet_ntoa_r(*(struct in_addr *)(ip + 12), s);
			temp = strlen(s);
			return len + temp;
		}
#endif
		temp = ((unsigned long)(unsigned char)ip[j] << 8) +
		    (unsigned long)(unsigned char)ip[j + 1];
		if (temp == 0) {
			if (!compressing) {
				compressing = 1;
				if (j == 0) {
					*s++ = ':';
					++len;
				}
			}
		} else {
			if (compressing) {
				compressing = 0;
				*s++ = ':';
				++len;
			}
			i = fmt_xlong(s, temp);
			len += i;
			s += i;
			if (j < 14) {
				*s++ = ':';
				++len;
			}
		}
	}
	if (compressing) {
		*s++ = ':';
		++len;
	}
	*s = 0;
	return len;
}

static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
					struct pktgen_dev *pkt_dev)
{
	struct sk_buff *skb = NULL;
	__u8 *eth;
	struct udphdr *udph;
	int datalen;
	struct ipv6hdr *iph;
	struct pktgen_hdr *pgh = NULL;

	/* Update any of the values, used when we're incrementing various
	 * fields.
	 */
	mod_cur_headers(pkt_dev);

	skb = alloc_skb(pkt_dev->cur_pkt_size + 64 + 16, GFP_ATOMIC);
	if (!skb) {
		sprintf(pkt_dev->result, "No memory");
		return NULL;
	}

	skb_reserve(skb, 16);

	/*  Reserve for ethernet and IP header  */
	eth = (__u8 *) skb_push(skb, 14);
	iph = (struct ipv6hdr *)skb_put(skb, sizeof(struct ipv6hdr));
	udph = (struct udphdr *)skb_put(skb, sizeof(struct udphdr));

	memcpy(eth, pkt_dev->hh, 12);
	*(u16 *) & eth[12] = __constant_htons(ETH_P_IPV6);

	datalen = pkt_dev->cur_pkt_size - 14 - sizeof(struct ipv6hdr) - sizeof(struct udphdr);	/* Eth + IPh + UDPh */

	if (datalen < sizeof(struct pktgen_hdr)) {
		datalen = sizeof(struct pktgen_hdr);
		if (net_ratelimit())
			printk(KERN_INFO "pktgen: increased datalen to %d\n",
			       datalen);
	}

	udph->source = htons(pkt_dev->cur_udp_src);
	udph->dest = htons(pkt_dev->cur_udp_dst);
	udph->len = htons(datalen + sizeof(struct udphdr));
	udph->check = 0;	/* No checksum */

	*(u32 *) iph = __constant_htonl(0x60000000);	/* Version + flow */

	iph->hop_limit = 32;

	iph->payload_len = htons(sizeof(struct udphdr) + datalen);
	iph->nexthdr = IPPROTO_UDP;

	ipv6_addr_copy(&iph->daddr, &pkt_dev->cur_in6_daddr);
	ipv6_addr_copy(&iph->saddr, &pkt_dev->cur_in6_saddr);

	skb->mac.raw = ((u8 *) iph) - 14;
	skb->protocol = __constant_htons(ETH_P_IPV6);
	skb->dev = odev;
	skb->pkt_type = PACKET_HOST;

	if (pkt_dev->nfrags <= 0)
		pgh = (struct pktgen_hdr *)skb_put(skb, datalen);
	else {
		int frags = pkt_dev->nfrags;
		int i;

		pgh = (struct pktgen_hdr *)(((char *)(udph)) + 8);

		if (frags > MAX_SKB_FRAGS)
			frags = MAX_SKB_FRAGS;
		if (datalen > frags * PAGE_SIZE) {
			skb_put(skb, datalen - frags * PAGE_SIZE);
			datalen = frags * PAGE_SIZE;
		}

		i = 0;
		while (datalen > 0) {
			struct page *page = alloc_pages(GFP_KERNEL, 0);
			skb_shinfo(skb)->frags[i].page = page;
			skb_shinfo(skb)->frags[i].page_offset = 0;
			skb_shinfo(skb)->frags[i].size =
			    (datalen < PAGE_SIZE ? datalen : PAGE_SIZE);
			datalen -= skb_shinfo(skb)->frags[i].size;
			skb->len += skb_shinfo(skb)->frags[i].size;
			skb->data_len += skb_shinfo(skb)->frags[i].size;
			i++;
			skb_shinfo(skb)->nr_frags = i;
		}

		while (i < frags) {
			int rem;

			if (i == 0)
				break;

			rem = skb_shinfo(skb)->frags[i - 1].size / 2;
			if (rem == 0)
				break;

			skb_shinfo(skb)->frags[i - 1].size -= rem;

			skb_shinfo(skb)->frags[i] =
			    skb_shinfo(skb)->frags[i - 1];
			get_page(skb_shinfo(skb)->frags[i].page);
			skb_shinfo(skb)->frags[i].page =
			    skb_shinfo(skb)->frags[i - 1].page;
			skb_shinfo(skb)->frags[i].page_offset +=
			    skb_shinfo(skb)->frags[i - 1].size;
			skb_shinfo(skb)->frags[i].size = rem;
			i++;
			skb_shinfo(skb)->nr_frags = i;
		}
	}

	/* Stamp the time, and sequence number, convert them to network byte order */
	/* should we update cloned packets too ? */
	if (pgh) {
		struct timeval timestamp;

		pgh->pgh_magic = htonl(PKTGEN_MAGIC);
		pgh->seq_num = htonl(pkt_dev->seq_num);

		do_gettimeofday(&timestamp);
		pgh->tv_sec = htonl(timestamp.tv_sec);
		pgh->tv_usec = htonl(timestamp.tv_usec);
	}
	pkt_dev->seq_num++;

	return skb;
}

static inline struct sk_buff *fill_packet(struct net_device *odev,
					  struct pktgen_dev *pkt_dev)
{
	if (pkt_dev->flags & F_IPV6)
		return fill_packet_ipv6(odev, pkt_dev);
	else
		return fill_packet_ipv4(odev, pkt_dev);
}

static void pktgen_clear_counters(struct pktgen_dev *pkt_dev)
{
	pkt_dev->seq_num = 1;
	pkt_dev->idle_acc = 0;
	pkt_dev->sofar = 0;
	pkt_dev->tx_bytes = 0;
	pkt_dev->errors = 0;
}

/* Set up structure for sending pkts, clear counters */

static void pktgen_run(struct pktgen_thread *t)
{
	struct pktgen_dev *pkt_dev;
	int started = 0;

	PG_DEBUG(printk("pktgen: entering pktgen_run. %p\n", t));

	if_lock(t);
	list_for_each_entry(pkt_dev, &t->if_list, list) {

		/*
		 * setup odev and create initial packet.
		 */
		pktgen_setup_inject(pkt_dev);

		if (pkt_dev->odev) {
			pktgen_clear_counters(pkt_dev);
			pkt_dev->running = 1;	/* Cranke yeself! */
			pkt_dev->skb = NULL;
			pkt_dev->started_at = getCurUs();
			pkt_dev->next_tx_us = getCurUs();	/* Transmit immediately */
			pkt_dev->next_tx_ns = 0;

			strcpy(pkt_dev->result, "Starting");
			started++;
		} else
			strcpy(pkt_dev->result, "Error starting");
	}
	if_unlock(t);
	if (started)
		t->control &= ~(T_STOP);
}

static void pktgen_stop_all_threads_ifs(void)
{
	struct pktgen_thread *t;

	PG_DEBUG(printk("pktgen: entering pktgen_stop_all_threads_ifs.\n"));

	mutex_lock(&pktgen_thread_lock);

	list_for_each_entry(t, &pktgen_threads, th_list)
		t->control |= T_STOP;

	mutex_unlock(&pktgen_thread_lock);
}

static int thread_is_running(struct pktgen_thread *t)
{
	struct pktgen_dev *pkt_dev;
	int res = 0;

	list_for_each_entry(pkt_dev, &t->if_list, list)
		if (pkt_dev->running) {
			res = 1;
			break;
		}
	return res;
}

static int pktgen_wait_thread_run(struct pktgen_thread *t)
{
	if_lock(t);

	while (thread_is_running(t)) {

		if_unlock(t);

		msleep_interruptible(100);

		if (signal_pending(current))
			goto signal;
		if_lock(t);
	}
	if_unlock(t);
	return 1;
signal:
	return 0;
}

static int pktgen_wait_all_threads_run(void)
{
	struct pktgen_thread *t;
	int sig = 1;

	mutex_lock(&pktgen_thread_lock);

	list_for_each_entry(t, &pktgen_threads, th_list) {
		sig = pktgen_wait_thread_run(t);
		if (sig == 0)
			break;
	}

	if (sig == 0)
		list_for_each_entry(t, &pktgen_threads, th_list)
			t->control |= (T_STOP);

	mutex_unlock(&pktgen_thread_lock);
	return sig;
}

static void pktgen_run_all_threads(void)
{
	struct pktgen_thread *t;

	PG_DEBUG(printk("pktgen: entering pktgen_run_all_threads.\n"));

	mutex_lock(&pktgen_thread_lock);

	list_for_each_entry(t, &pktgen_threads, th_list)
		t->control |= (T_RUN);

	mutex_unlock(&pktgen_thread_lock);

	schedule_timeout_interruptible(msecs_to_jiffies(125));	/* Propagate thread->control  */

	pktgen_wait_all_threads_run();
}

static void show_results(struct pktgen_dev *pkt_dev, int nr_frags)
{
	__u64 total_us, bps, mbps, pps, idle;
	char *p = pkt_dev->result;

	total_us = pkt_dev->stopped_at - pkt_dev->started_at;

	idle = pkt_dev->idle_acc;

	p += sprintf(p, "OK: %llu(c%llu+d%llu) usec, %llu (%dbyte,%dfrags)\n",
		     (unsigned long long)total_us,
		     (unsigned long long)(total_us - idle),
		     (unsigned long long)idle,
		     (unsigned long long)pkt_dev->sofar,
		     pkt_dev->cur_pkt_size, nr_frags);

	pps = pkt_dev->sofar * USEC_PER_SEC;

	while ((total_us >> 32) != 0) {
		pps >>= 1;
		total_us >>= 1;
	}

	do_div(pps, total_us);

	bps = pps * 8 * pkt_dev->cur_pkt_size;

	mbps = bps;
	do_div(mbps, 1000000);
	p += sprintf(p, "  %llupps %lluMb/sec (%llubps) errors: %llu",
		     (unsigned long long)pps,
		     (unsigned long long)mbps,
		     (unsigned long long)bps,
		     (unsigned long long)pkt_dev->errors);
}

/* Set stopped-at timer, remove from running list, do counters & statistics */

static int pktgen_stop_device(struct pktgen_dev *pkt_dev)
{
	int nr_frags = pkt_dev->skb ? skb_shinfo(pkt_dev->skb)->nr_frags : -1;

	if (!pkt_dev->running) {
		printk("pktgen: interface: %s is already stopped\n",
		       pkt_dev->ifname);
		return -EINVAL;
	}

	pkt_dev->stopped_at = getCurUs();
	pkt_dev->running = 0;

	show_results(pkt_dev, nr_frags);

	return 0;
}

static struct pktgen_dev *next_to_run(struct pktgen_thread *t)
{
	struct pktgen_dev *pkt_dev, *best = NULL;

	if_lock(t);

	list_for_each_entry(pkt_dev, &t->if_list, list) {
		if (!pkt_dev->running)
			continue;
		if (best == NULL)
			best = pkt_dev;
		else if (pkt_dev->next_tx_us < best->next_tx_us)
			best = pkt_dev;
	}
	if_unlock(t);
	return best;
}

static void pktgen_stop(struct pktgen_thread *t)
{
	struct pktgen_dev *pkt_dev;

	PG_DEBUG(printk("pktgen: entering pktgen_stop\n"));

	if_lock(t);

	list_for_each_entry(pkt_dev, &t->if_list, list) {
		pktgen_stop_device(pkt_dev);
		if (pkt_dev->skb)
			kfree_skb(pkt_dev->skb);

		pkt_dev->skb = NULL;
	}

	if_unlock(t);
}

/*
 * one of our devices needs to be removed - find it
 * and remove it
 */
static void pktgen_rem_one_if(struct pktgen_thread *t)
{
	struct list_head *q, *n;
	struct pktgen_dev *cur;

	PG_DEBUG(printk("pktgen: entering pktgen_rem_one_if\n"));

	if_lock(t);

	list_for_each_safe(q, n, &t->if_list) {
		cur = list_entry(q, struct pktgen_dev, list);

		if (!cur->removal_mark)
			continue;

		if (cur->skb)
			kfree_skb(cur->skb);
		cur->skb = NULL;

		pktgen_remove_device(t, cur);

		break;
	}

	if_unlock(t);
}

static void pktgen_rem_all_ifs(struct pktgen_thread *t)
{
	struct list_head *q, *n;
	struct pktgen_dev *cur;

	/* Remove all devices, free mem */

	PG_DEBUG(printk("pktgen: entering pktgen_rem_all_ifs\n"));
	if_lock(t);

	list_for_each_safe(q, n, &t->if_list) {
		cur = list_entry(q, struct pktgen_dev, list);

		if (cur->skb)
			kfree_skb(cur->skb);
		cur->skb = NULL;

		pktgen_remove_device(t, cur);
	}

	if_unlock(t);
}

static void pktgen_rem_thread(struct pktgen_thread *t)
{
	/* Remove from the thread list */

	remove_proc_entry(t->name, pg_proc_dir);

	mutex_lock(&pktgen_thread_lock);

	list_del(&t->th_list);

	mutex_unlock(&pktgen_thread_lock);
}

static __inline__ void pktgen_xmit(struct pktgen_dev *pkt_dev)
{
	struct net_device *odev = NULL;
	__u64 idle_start = 0;
	int ret;

	odev = pkt_dev->odev;

	if (pkt_dev->delay_us || pkt_dev->delay_ns) {
		u64 now;

		now = getCurUs();
		if (now < pkt_dev->next_tx_us)
			spin(pkt_dev, pkt_dev->next_tx_us);

		/* This is max DELAY, this has special meaning of
		 * "never transmit"
		 */
		if (pkt_dev->delay_us == 0x7FFFFFFF) {
			pkt_dev->next_tx_us = getCurUs() + pkt_dev->delay_us;
			pkt_dev->next_tx_ns = pkt_dev->delay_ns;
			goto out;
		}
	}

	if (netif_queue_stopped(odev) || need_resched()) {
		idle_start = getCurUs();

		if (!netif_running(odev)) {
			pktgen_stop_device(pkt_dev);
			if (pkt_dev->skb)
				kfree_skb(pkt_dev->skb);
			pkt_dev->skb = NULL;
			goto out;
		}
		if (need_resched())
			schedule();

		pkt_dev->idle_acc += getCurUs() - idle_start;

		if (netif_queue_stopped(odev)) {
			pkt_dev->next_tx_us = getCurUs();	/* TODO */
			pkt_dev->next_tx_ns = 0;
			goto out;	/* Try the next interface */
		}
	}

	if (pkt_dev->last_ok || !pkt_dev->skb) {
		if ((++pkt_dev->clone_count >= pkt_dev->clone_skb)
		    || (!pkt_dev->skb)) {
			/* build a new pkt */
			if (pkt_dev->skb)
				kfree_skb(pkt_dev->skb);

			pkt_dev->skb = fill_packet(odev, pkt_dev);
			if (pkt_dev->skb == NULL) {
				printk("pktgen: ERROR: couldn't allocate skb in fill_packet.\n");
				schedule();
				pkt_dev->clone_count--;	/* back out increment, OOM */
				goto out;
			}
			pkt_dev->allocated_skbs++;
			pkt_dev->clone_count = 0;	/* reset counter */
		}
	}

	spin_lock_bh(&odev->xmit_lock);
	if (!netif_queue_stopped(odev)) {

		atomic_inc(&(pkt_dev->skb->users));
	      retry_now:
		ret = odev->hard_start_xmit(pkt_dev->skb, odev);
		if (likely(ret == NETDEV_TX_OK)) {
			pkt_dev->last_ok = 1;
			pkt_dev->sofar++;
			pkt_dev->seq_num++;
			pkt_dev->tx_bytes += pkt_dev->cur_pkt_size;

		} else if (ret == NETDEV_TX_LOCKED
			   && (odev->features & NETIF_F_LLTX)) {
			cpu_relax();
			goto retry_now;
		} else {	/* Retry it next time */

			atomic_dec(&(pkt_dev->skb->users));

			if (debug && net_ratelimit())
				printk(KERN_INFO "pktgen: Hard xmit error\n");

			pkt_dev->errors++;
			pkt_dev->last_ok = 0;
		}

		pkt_dev->next_tx_us = getCurUs();
		pkt_dev->next_tx_ns = 0;

		pkt_dev->next_tx_us += pkt_dev->delay_us;
		pkt_dev->next_tx_ns += pkt_dev->delay_ns;

		if (pkt_dev->next_tx_ns > 1000) {
			pkt_dev->next_tx_us++;
			pkt_dev->next_tx_ns -= 1000;
		}
	}

	else {			/* Retry it next time */
		pkt_dev->last_ok = 0;
		pkt_dev->next_tx_us = getCurUs();	/* TODO */
		pkt_dev->next_tx_ns = 0;
	}

	spin_unlock_bh(&odev->xmit_lock);

	/* If pkt_dev->count is zero, then run forever */
	if ((pkt_dev->count != 0) && (pkt_dev->sofar >= pkt_dev->count)) {
		if (atomic_read(&(pkt_dev->skb->users)) != 1) {
			idle_start = getCurUs();
			while (atomic_read(&(pkt_dev->skb->users)) != 1) {
				if (signal_pending(current)) {
					break;
				}
				schedule();
			}
			pkt_dev->idle_acc += getCurUs() - idle_start;
		}

		/* Done with this */
		pktgen_stop_device(pkt_dev);
		if (pkt_dev->skb)
			kfree_skb(pkt_dev->skb);
		pkt_dev->skb = NULL;
	}
out:;
}

/* 
 * Main loop of the thread goes here
 */

static void pktgen_thread_worker(struct pktgen_thread *t)
{
	DEFINE_WAIT(wait);
	struct pktgen_dev *pkt_dev = NULL;
	int cpu = t->cpu;
	sigset_t tmpsig;
	u32 max_before_softirq;
	u32 tx_since_softirq = 0;

	daemonize("pktgen/%d", cpu);

	/* Block all signals except SIGKILL, SIGSTOP and SIGTERM */

	spin_lock_irq(&current->sighand->siglock);
	tmpsig = current->blocked;
	siginitsetinv(&current->blocked,
		      sigmask(SIGKILL) | sigmask(SIGSTOP) | sigmask(SIGTERM));

	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	/* Migrate to the right CPU */
	set_cpus_allowed(current, cpumask_of_cpu(cpu));
	if (smp_processor_id() != cpu)
		BUG();

	init_waitqueue_head(&t->queue);

	t->control &= ~(T_TERMINATE);
	t->control &= ~(T_RUN);
	t->control &= ~(T_STOP);
	t->control &= ~(T_REMDEVALL);
	t->control &= ~(T_REMDEV);

	t->pid = current->pid;

	PG_DEBUG(printk("pktgen: starting pktgen/%d:  pid=%d\n", cpu, current->pid));

	max_before_softirq = t->max_before_softirq;

	__set_current_state(TASK_INTERRUPTIBLE);
	mb();

	while (1) {

		__set_current_state(TASK_RUNNING);

		/*
		 * Get next dev to xmit -- if any.
		 */

		pkt_dev = next_to_run(t);

		if (pkt_dev) {

			pktgen_xmit(pkt_dev);

			/*
			 * We like to stay RUNNING but must also give
			 * others fair share.
			 */

			tx_since_softirq += pkt_dev->last_ok;

			if (tx_since_softirq > max_before_softirq) {
				if (local_softirq_pending())
					do_softirq();
				tx_since_softirq = 0;
			}
		} else {
			prepare_to_wait(&(t->queue), &wait, TASK_INTERRUPTIBLE);
			schedule_timeout(HZ / 10);
			finish_wait(&(t->queue), &wait);
		}

		/*
		 * Back from sleep, either due to the timeout or signal.
		 * We check if we have any "posted" work for us.
		 */

		if (t->control & T_TERMINATE || signal_pending(current))
			/* we received a request to terminate ourself */
			break;

		if (t->control & T_STOP) {
			pktgen_stop(t);
			t->control &= ~(T_STOP);
		}

		if (t->control & T_RUN) {
			pktgen_run(t);
			t->control &= ~(T_RUN);
		}

		if (t->control & T_REMDEVALL) {
			pktgen_rem_all_ifs(t);
			t->control &= ~(T_REMDEVALL);
		}

		if (t->control & T_REMDEV) {
			pktgen_rem_one_if(t);
			t->control &= ~(T_REMDEV);
		}

		if (need_resched())
			schedule();
	}

	PG_DEBUG(printk("pktgen: %s stopping all device\n", t->name));
	pktgen_stop(t);

	PG_DEBUG(printk("pktgen: %s removing all device\n", t->name));
	pktgen_rem_all_ifs(t);

	PG_DEBUG(printk("pktgen: %s removing thread.\n", t->name));
	pktgen_rem_thread(t);

	t->removed = 1;
}

static struct pktgen_dev *pktgen_find_dev(struct pktgen_thread *t,
					  const char *ifname)
{
	struct pktgen_dev *p, *pkt_dev = NULL;
	if_lock(t);

	list_for_each_entry(p, &t->if_list, list)
		if (strncmp(p->ifname, ifname, IFNAMSIZ) == 0) {
			pkt_dev = p;
			break;
		}

	if_unlock(t);
	PG_DEBUG(printk("pktgen: find_dev(%s) returning %p\n", ifname, pkt_dev));
	return pkt_dev;
}

/* 
 * Adds a dev at front of if_list. 
 */

static int add_dev_to_thread(struct pktgen_thread *t,
			     struct pktgen_dev *pkt_dev)
{
	int rv = 0;

	if_lock(t);

	if (pkt_dev->pg_thread) {
		printk("pktgen: ERROR:  already assigned to a thread.\n");
		rv = -EBUSY;
		goto out;
	}

	list_add(&pkt_dev->list, &t->if_list);
	pkt_dev->pg_thread = t;
	pkt_dev->running = 0;

out:
	if_unlock(t);
	return rv;
}

/* Called under thread lock */

static int pktgen_add_device(struct pktgen_thread *t, const char *ifname)
{
	struct pktgen_dev *pkt_dev;
	struct proc_dir_entry *pe;

	/* We don't allow a device to be on several threads */

	pkt_dev = __pktgen_NN_threads(ifname, FIND);
	if (pkt_dev) {
		printk("pktgen: ERROR: interface already used.\n");
		return -EBUSY;
	}

	pkt_dev = kzalloc(sizeof(struct pktgen_dev), GFP_KERNEL);
	if (!pkt_dev)
		return -ENOMEM;

	pkt_dev->flows = vmalloc(MAX_CFLOWS * sizeof(struct flow_state));
	if (pkt_dev->flows == NULL) {
		kfree(pkt_dev);
		return -ENOMEM;
	}
	memset(pkt_dev->flows, 0, MAX_CFLOWS * sizeof(struct flow_state));

	pkt_dev->removal_mark = 0;
	pkt_dev->min_pkt_size = ETH_ZLEN;
	pkt_dev->max_pkt_size = ETH_ZLEN;
	pkt_dev->nfrags = 0;
	pkt_dev->clone_skb = pg_clone_skb_d;
	pkt_dev->delay_us = pg_delay_d / 1000;
	pkt_dev->delay_ns = pg_delay_d % 1000;
	pkt_dev->count = pg_count_d;
	pkt_dev->sofar = 0;
	pkt_dev->udp_src_min = 9;	/* sink port */
	pkt_dev->udp_src_max = 9;
	pkt_dev->udp_dst_min = 9;
	pkt_dev->udp_dst_max = 9;

	strncpy(pkt_dev->ifname, ifname, IFNAMSIZ);

	if (!pktgen_setup_dev(pkt_dev)) {
		printk("pktgen: ERROR: pktgen_setup_dev failed.\n");
		if (pkt_dev->flows)
			vfree(pkt_dev->flows);
		kfree(pkt_dev);
		return -ENODEV;
	}

	pe = create_proc_entry(ifname, 0600, pg_proc_dir);
	if (!pe) {
		printk("pktgen: cannot create %s/%s procfs entry.\n",
		       PG_PROC_DIR, ifname);
		if (pkt_dev->flows)
			vfree(pkt_dev->flows);
		kfree(pkt_dev);
		return -EINVAL;
	}
	pe->proc_fops = &pktgen_if_fops;
	pe->data = pkt_dev;

	return add_dev_to_thread(t, pkt_dev);
}

static struct pktgen_thread *__init pktgen_find_thread(const char *name)
{
	struct pktgen_thread *t;

	mutex_lock(&pktgen_thread_lock);

	list_for_each_entry(t, &pktgen_threads, th_list)
		if (strcmp(t->name, name) == 0) {
			mutex_unlock(&pktgen_thread_lock);
			return t;
		}

	mutex_unlock(&pktgen_thread_lock);
	return NULL;
}

static int __init pktgen_create_thread(const char *name, int cpu)
{
	int err;
	struct pktgen_thread *t = NULL;
	struct proc_dir_entry *pe;

	if (strlen(name) > 31) {
		printk("pktgen: ERROR:  Thread name cannot be more than 31 characters.\n");
		return -EINVAL;
	}

	if (pktgen_find_thread(name)) {
		printk("pktgen: ERROR: thread: %s already exists\n", name);
		return -EINVAL;
	}

	t = kzalloc(sizeof(struct pktgen_thread), GFP_KERNEL);
	if (!t) {
		printk("pktgen: ERROR: out of memory, can't create new thread.\n");
		return -ENOMEM;
	}

	strcpy(t->name, name);
	spin_lock_init(&t->if_lock);
	t->cpu = cpu;

	pe = create_proc_entry(t->name, 0600, pg_proc_dir);
	if (!pe) {
		printk("pktgen: cannot create %s/%s procfs entry.\n",
		       PG_PROC_DIR, t->name);
		kfree(t);
		return -EINVAL;
	}

	pe->proc_fops = &pktgen_thread_fops;
	pe->data = t;

	INIT_LIST_HEAD(&t->if_list);

	list_add_tail(&t->th_list, &pktgen_threads);

	t->removed = 0;

	err = kernel_thread((void *)pktgen_thread_worker, (void *)t,
			  CLONE_FS | CLONE_FILES | CLONE_SIGHAND);
	if (err < 0) {
		printk("pktgen: kernel_thread() failed for cpu %d\n", t->cpu);
		remove_proc_entry(t->name, pg_proc_dir);
		list_del(&t->th_list);
		kfree(t);
		return err;
	}

	return 0;
}

/* 
 * Removes a device from the thread if_list. 
 */
static void _rem_dev_from_if_list(struct pktgen_thread *t,
				  struct pktgen_dev *pkt_dev)
{
	struct list_head *q, *n;
	struct pktgen_dev *p;

	list_for_each_safe(q, n, &t->if_list) {
		p = list_entry(q, struct pktgen_dev, list);
		if (p == pkt_dev)
			list_del(&p->list);
	}
}

static int pktgen_remove_device(struct pktgen_thread *t,
				struct pktgen_dev *pkt_dev)
{

	PG_DEBUG(printk("pktgen: remove_device pkt_dev=%p\n", pkt_dev));

	if (pkt_dev->running) {
		printk("pktgen:WARNING: trying to remove a running interface, stopping it now.\n");
		pktgen_stop_device(pkt_dev);
	}

	/* Dis-associate from the interface */

	if (pkt_dev->odev) {
		dev_put(pkt_dev->odev);
		pkt_dev->odev = NULL;
	}

	/* And update the thread if_list */

	_rem_dev_from_if_list(t, pkt_dev);

	/* Clean up proc file system */

	remove_proc_entry(pkt_dev->ifname, pg_proc_dir);

	if (pkt_dev->flows)
		vfree(pkt_dev->flows);
	kfree(pkt_dev);
	return 0;
}

static int __init pg_init(void)
{
	int cpu;
	struct proc_dir_entry *pe;

	printk(version);

	pg_proc_dir = proc_mkdir(PG_PROC_DIR, proc_net);
	if (!pg_proc_dir)
		return -ENODEV;
	pg_proc_dir->owner = THIS_MODULE;

	pe = create_proc_entry(PGCTRL, 0600, pg_proc_dir);
	if (pe == NULL) {
		printk("pktgen: ERROR: cannot create %s procfs entry.\n",
		       PGCTRL);
		proc_net_remove(PG_PROC_DIR);
		return -EINVAL;
	}

	pe->proc_fops = &pktgen_fops;
	pe->data = NULL;

	/* Register us to receive netdevice events */
	register_netdevice_notifier(&pktgen_notifier_block);

	for_each_online_cpu(cpu) {
		int err;
		char buf[30];

		sprintf(buf, "kpktgend_%i", cpu);
		err = pktgen_create_thread(buf, cpu);
		if (err)
			printk("pktgen: WARNING: Cannot create thread for cpu %d (%d)\n",
					cpu, err);
	}

	if (list_empty(&pktgen_threads)) {
		printk("pktgen: ERROR: Initialization failed for all threads\n");
		unregister_netdevice_notifier(&pktgen_notifier_block);
		remove_proc_entry(PGCTRL, pg_proc_dir);
		proc_net_remove(PG_PROC_DIR);
		return -ENODEV;
	}

	return 0;
}

static void __exit pg_cleanup(void)
{
	struct pktgen_thread *t;
	struct list_head *q, *n;
	wait_queue_head_t queue;
	init_waitqueue_head(&queue);

	/* Stop all interfaces & threads */

	list_for_each_safe(q, n, &pktgen_threads) {
		t = list_entry(q, struct pktgen_thread, th_list);
		t->control |= (T_TERMINATE);

		wait_event_interruptible_timeout(queue, (t->removed == 1), HZ);
	}

	/* Un-register us from receiving netdevice events */
	unregister_netdevice_notifier(&pktgen_notifier_block);

	/* Clean up proc file system */
	remove_proc_entry(PGCTRL, pg_proc_dir);
	proc_net_remove(PG_PROC_DIR);
}

module_init(pg_init);
module_exit(pg_cleanup);

MODULE_AUTHOR("Robert Olsson <robert.olsson@its.uu.se");
MODULE_DESCRIPTION("Packet Generator tool");
MODULE_LICENSE("GPL");
module_param(pg_count_d, int, 0);
module_param(pg_delay_d, int, 0);
module_param(pg_clone_skb_d, int, 0);
module_param(debug, int, 0);