net/core/pktgen.c - linux/kernel/git/gregkh/usb - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * 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 Låås <jens.laas@data.slu.se>
  *
  * 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.rst 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_list is RCU protected, and the if_lock remains to protect updating
  * of if_list, from "add_device" as it invoked from userspace (via proc write).
  *
  * 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 warning
  *
  * 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
  *
  * MPLS support by Steven Whitehouse <steve@chygwyn.com>
  *
  * 802.1Q/Q-in-Q support by Francesco Fondelli (FF) <francesco.fondelli@gmail.com>
  *
  * Fixed src_mac command to set source mac of packet to value specified in
  * command by Adit Ranadive <adit.262@gmail.com>
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/sys.h>
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/kernel.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/hrtimer.h>
 #include <linux/freezer.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/if_vlan.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 <linux/kthread.h>
 #include <linux/prefetch.h>
 #include <linux/mmzone.h>
 #include <net/net_namespace.h>
 #include <net/checksum.h>
 #include <net/ipv6.h>
 #include <net/udp.h>
 #include <net/ip6_checksum.h>
 #include <net/addrconf.h>
 #ifdef CONFIG_XFRM
 #include <net/xfrm.h>
 #endif
 #include <net/netns/generic.h>
 #include <asm/byteorder.h>
 #include <linux/rcupdate.h>
 #include <linux/bitops.h>
 #include <linux/io.h>
 #include <linux/timex.h>
 #include <linux/uaccess.h>
 #include <asm/dma.h>
 #include <asm/div64.h>		/* do_div */

 #define VERSION	"2.75"
 #define IP_NAME_SZ 32
 #define MAX_MPLS_LABELS 16 /* This is the max label stack depth */
 #define MPLS_STACK_BOTTOM htonl(0x00000100)
 /* Max number of internet mix entries that can be specified in imix_weights. */
 #define MAX_IMIX_ENTRIES 20
 #define IMIX_PRECISION 100 /* Precision of IMIX distribution */

 #define func_enter() pr_debug("entering %s\n", __func__);

 #define PKT_FLAGS							\
 	pf(IPV6)		/* Interface in IPV6 Mode */		\
 	pf(IPSRC_RND)		/* IP-Src Random  */			\
 	pf(IPDST_RND)		/* IP-Dst Random  */			\
 	pf(TXSIZE_RND)		/* Transmit size is random */		\
 	pf(UDPSRC_RND)		/* UDP-Src Random */			\
 	pf(UDPDST_RND)		/* UDP-Dst Random */			\
 	pf(UDPCSUM)		/* Include UDP checksum */		\
 	pf(NO_TIMESTAMP)	/* Don't timestamp packets (default TS) */ \
 	pf(MPLS_RND)		/* Random MPLS labels */		\
 	pf(QUEUE_MAP_RND)	/* queue map Random */			\
 	pf(QUEUE_MAP_CPU)	/* queue map mirrors smp_processor_id() */ \
 	pf(FLOW_SEQ)		/* Sequential flows */			\
 	pf(IPSEC)		/* ipsec on for flows */		\
 	pf(MACSRC_RND)		/* MAC-Src Random */			\
 	pf(MACDST_RND)		/* MAC-Dst Random */			\
 	pf(VID_RND)		/* Random VLAN ID */			\
 	pf(SVID_RND)		/* Random SVLAN ID */			\
 	pf(NODE)		/* Node memory alloc*/			\
 	pf(SHARED)		/* Shared SKB */			\

 #define pf(flag)		flag##_SHIFT,
 enum pkt_flags {
 	PKT_FLAGS
 };
 #undef pf

 /* Device flag bits */
 #define pf(flag)		static const __u32 F_##flag = (1<<flag##_SHIFT);
 PKT_FLAGS
 #undef pf

 #define pf(flag)		__stringify(flag),
 static char *pkt_flag_names[] = {
 	PKT_FLAGS
 };
 #undef pf

 #define NR_PKT_FLAGS		ARRAY_SIZE(pkt_flag_names)

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

 /* Xmit modes */
 #define M_START_XMIT		0	/* Default normal TX */
 #define M_NETIF_RECEIVE 	1	/* Inject packets into stack */
 #define M_QUEUE_XMIT		2	/* Inject packet into qdisc */

 /* If lock -- protects updating of if_list */
 #define   if_lock(t)           mutex_lock(&(t->if_lock));
 #define   if_unlock(t)           mutex_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"

 #define MAX_CFLOWS  65536

 #define VLAN_TAG_SIZE(x) ((x)->vlan_id == 0xffff ? 0 : 4)
 #define SVLAN_TAG_SIZE(x) ((x)->svlan_id == 0xffff ? 0 : 4)

 struct imix_pkt {
 	u64 size;
 	u64 weight;
 	u64 count_so_far;
 };

 struct flow_state {
 	__be32 cur_daddr;
 	int count;
 #ifdef CONFIG_XFRM
 	struct xfrm_state *x;
 #endif
 	__u32 flags;
 };

 /* flow flag bits */
 #define F_INIT   (1<<0)		/* flow has been initialized */

 struct pktgen_dev {
 	/*
 	 * Try to keep frequent/infrequent used vars. separated.
 	 */
 	struct proc_dir_entry *entry;	/* proc file */
 	struct pktgen_thread *pg_thread;/* the owner */
 	struct list_head list;		/* chaining in the thread's run-queue */
 	struct rcu_head	 rcu;		/* freed by RCU */

 	int running;		/* if 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 xmit_mode;
 	int min_pkt_size;
 	int max_pkt_size;
 	int pkt_overhead;	/* overhead for MPLS, VLANs, IPSEC etc */
 	int nfrags;
 	int removal_mark;	/* non-zero => the device is marked for
 				 * removal by worker thread */

 	struct page *page;
 	u64 delay;		/* nano-seconds */

 	__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, */

 	/* runtime counters relating to clone_skb */

 	__u32 clone_count;
 	int last_ok;		/* Was last skb sent?
 				 * Or a failed transmit of some sort?
 				 * This will keep sequence numbers in order
 				 */
 	ktime_t next_tx;
 	ktime_t started_at;
 	ktime_t stopped_at;
 	u64	idle_acc;	/* nano-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.
 				 * 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.
 	 */
 	__be32 saddr_min;	/* inclusive, source IP address */
 	__be32 saddr_max;	/* exclusive, source IP address */
 	__be32 daddr_min;	/* inclusive, dest IP address */
 	__be32 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 */

 	/* DSCP + ECN */
 	__u8 tos;            /* six MSB of (former) IPv4 TOS
 				are for dscp codepoint */
 	__u8 traffic_class;  /* ditto for the (former) Traffic Class in IPv6
 				(see RFC 3260, sec. 4) */

 	/* IMIX */
 	unsigned int n_imix_entries;
 	struct imix_pkt imix_entries[MAX_IMIX_ENTRIES];
 	/* Maps 0-IMIX_PRECISION range to imix_entry based on probability*/
 	__u8 imix_distribution[IMIX_PRECISION];

 	/* MPLS */
 	unsigned int nr_labels;	/* Depth of stack, 0 = no MPLS */
 	__be32 labels[MAX_MPLS_LABELS];

 	/* VLAN/SVLAN (802.1Q/Q-in-Q) */
 	__u8  vlan_p;
 	__u8  vlan_cfi;
 	__u16 vlan_id;  /* 0xffff means no vlan tag */

 	__u8  svlan_p;
 	__u8  svlan_cfi;
 	__u16 svlan_id; /* 0xffff means no svlan tag */

 	__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;
 	__be32 cur_saddr;
 	__be32 cur_daddr;
 	__u16 ip_id;
 	__u16 cur_udp_dst;
 	__u16 cur_udp_src;
 	__u16 cur_queue_map;
 	__u32 cur_pkt_size;
 	__u32 last_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, 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.
 				  * Set when the user specifies the out-going
 				  * device name (not when the inject is
 				  * started as it used to do.)
 				  */
 	netdevice_tracker dev_tracker;
 	char odevname[32];
 	struct flow_state *flows;
 	unsigned int cflows;	/* Concurrent flows (config) */
 	unsigned int lflow;		/* Flow length  (config) */
 	unsigned int nflows;	/* accumulated flows (stats) */
 	unsigned int curfl;		/* current sequenced flow (state)*/

 	u16 queue_map_min;
 	u16 queue_map_max;
 	__u32 skb_priority;	/* skb priority field */
 	unsigned int burst;	/* number of duplicated packets to burst */
 	int node;               /* Memory node */

 #ifdef CONFIG_XFRM
 	__u8	ipsmode;		/* IPSEC mode (config) */
 	__u8	ipsproto;		/* IPSEC type (config) */
 	__u32	spi;
 	struct xfrm_dst xdst;
 	struct dst_ops dstops;
 #endif
 	char result[512];
 };

 struct pktgen_hdr {
 	__be32 pgh_magic;
 	__be32 seq_num;
 	__be32 tv_sec;
 	__be32 tv_usec;
 };


 static unsigned int pg_net_id __read_mostly;

 struct pktgen_net {
 	struct net		*net;
 	struct proc_dir_entry	*proc_dir;
 	struct list_head	pktgen_threads;
 	bool			pktgen_exiting;
 };

 struct pktgen_thread {
 	struct mutex if_lock;		/* for list of devices */
 	struct list_head if_list;	/* All device here */
 	struct list_head th_list;
 	struct task_struct *tsk;
 	char result[512];

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

 	u32 control;
 	int cpu;

 	wait_queue_head_t queue;
 	struct completion start_done;
 	struct pktgen_net *net;
 };

 #define REMOVE 1
 #define FIND   0

 static const char version[] =
 	"Packet Generator for packet performance testing. "
 	"Version: " VERSION "\n";

 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, bool exact);
 static int pktgen_device_event(struct notifier_block *, unsigned long, void *);
 static void pktgen_run_all_threads(struct pktgen_net *pn);
 static void pktgen_reset_all_threads(struct pktgen_net *pn);
 static void pktgen_stop_all_threads(struct pktgen_net *pn);

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

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

 static DEFINE_MUTEX(pktgen_thread_lock);

 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)
 {
 	char data[128];
 	struct pktgen_net *pn = net_generic(current->nsproxy->net_ns, pg_net_id);

 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;

 	if (count == 0)
 		return -EINVAL;

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

 	if (copy_from_user(data, buf, count))
 		return -EFAULT;

 	data[count - 1] = 0;	/* Strip trailing '\n' and terminate string */

 	if (!strcmp(data, "stop"))
 		pktgen_stop_all_threads(pn);
 	else if (!strcmp(data, "start"))
 		pktgen_run_all_threads(pn);
 	else if (!strcmp(data, "reset"))
 		pktgen_reset_all_threads(pn);
 	else
 		return -EINVAL;

 	return count;
 }

 static int pgctrl_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, pgctrl_show, pde_data(inode));
 }

 static const struct proc_ops pktgen_proc_ops = {
 	.proc_open	= pgctrl_open,
 	.proc_read	= seq_read,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= pgctrl_write,
 	.proc_release	= single_release,
 };

 static int pktgen_if_show(struct seq_file *seq, void *v)
 {
 	const struct pktgen_dev *pkt_dev = seq->private;
 	ktime_t stopped;
 	unsigned int i;
 	u64 idle;

 	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);

 	if (pkt_dev->n_imix_entries > 0) {
 		seq_puts(seq, "     imix_weights: ");
 		for (i = 0; i < pkt_dev->n_imix_entries; i++) {
 			seq_printf(seq, "%llu,%llu ",
 				   pkt_dev->imix_entries[i].size,
 				   pkt_dev->imix_entries[i].weight);
 		}
 		seq_puts(seq, "\n");
 	}

 	seq_printf(seq,
 		   "     frags: %d  delay: %llu  clone_skb: %d  ifname: %s\n",
 		   pkt_dev->nfrags, (unsigned long long) pkt_dev->delay,
 		   pkt_dev->clone_skb, pkt_dev->odevname);

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

 	seq_printf(seq,
 		   "     queue_map_min: %u  queue_map_max: %u\n",
 		   pkt_dev->queue_map_min,
 		   pkt_dev->queue_map_max);

 	if (pkt_dev->skb_priority)
 		seq_printf(seq, "     skb_priority: %u\n",
 			   pkt_dev->skb_priority);

 	if (pkt_dev->flags & F_IPV6) {
 		seq_printf(seq,
 			   "     saddr: %pI6c  min_saddr: %pI6c  max_saddr: %pI6c\n"
 			   "     daddr: %pI6c  min_daddr: %pI6c  max_daddr: %pI6c\n",
 			   &pkt_dev->in6_saddr,
 			   &pkt_dev->min_in6_saddr, &pkt_dev->max_in6_saddr,
 			   &pkt_dev->in6_daddr,
 			   &pkt_dev->min_in6_daddr, &pkt_dev->max_in6_daddr);
 	} else {
 		seq_printf(seq,
 			   "     dst_min: %s  dst_max: %s\n",
 			   pkt_dev->dst_min, pkt_dev->dst_max);
 		seq_printf(seq,
 			   "     src_min: %s  src_max: %s\n",
 			   pkt_dev->src_min, pkt_dev->src_max);
 	}

 	seq_puts(seq, "     src_mac: ");

 	seq_printf(seq, "%pM ",
 		   is_zero_ether_addr(pkt_dev->src_mac) ?
 			     pkt_dev->odev->dev_addr : pkt_dev->src_mac);

 	seq_puts(seq, "dst_mac: ");
 	seq_printf(seq, "%pM\n", pkt_dev->dst_mac);

 	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",
 		   pkt_dev->src_mac_count, pkt_dev->dst_mac_count);

 	if (pkt_dev->nr_labels) {
 		seq_puts(seq, "     mpls: ");
 		for (i = 0; i < pkt_dev->nr_labels; i++)
 			seq_printf(seq, "%08x%s", ntohl(pkt_dev->labels[i]),
 				   i == pkt_dev->nr_labels-1 ? "\n" : ", ");
 	}

 	if (pkt_dev->vlan_id != 0xffff)
 		seq_printf(seq, "     vlan_id: %u  vlan_p: %u  vlan_cfi: %u\n",
 			   pkt_dev->vlan_id, pkt_dev->vlan_p,
 			   pkt_dev->vlan_cfi);

 	if (pkt_dev->svlan_id != 0xffff)
 		seq_printf(seq, "     svlan_id: %u  vlan_p: %u  vlan_cfi: %u\n",
 			   pkt_dev->svlan_id, pkt_dev->svlan_p,
 			   pkt_dev->svlan_cfi);

 	if (pkt_dev->tos)
 		seq_printf(seq, "     tos: 0x%02x\n", pkt_dev->tos);

 	if (pkt_dev->traffic_class)
 		seq_printf(seq, "     traffic_class: 0x%02x\n", pkt_dev->traffic_class);

 	if (pkt_dev->burst > 1)
 		seq_printf(seq, "     burst: %d\n", pkt_dev->burst);

 	if (pkt_dev->node >= 0)
 		seq_printf(seq, "     node: %d\n", pkt_dev->node);

 	if (pkt_dev->xmit_mode == M_NETIF_RECEIVE)
 		seq_puts(seq, "     xmit_mode: netif_receive\n");
 	else if (pkt_dev->xmit_mode == M_QUEUE_XMIT)
 		seq_puts(seq, "     xmit_mode: xmit_queue\n");

 	seq_puts(seq, "     Flags: ");

 	for (i = 0; i < NR_PKT_FLAGS; i++) {
 		if (i == FLOW_SEQ_SHIFT)
 			if (!pkt_dev->cflows)
 				continue;

 		if (pkt_dev->flags & (1 << i)) {
 			seq_printf(seq, "%s  ", pkt_flag_names[i]);
 #ifdef CONFIG_XFRM
 			if (i == IPSEC_SHIFT && pkt_dev->spi)
 				seq_printf(seq, "spi:%u  ", pkt_dev->spi);
 #endif
 		} else if (i == FLOW_SEQ_SHIFT) {
 			seq_puts(seq, "FLOW_RND  ");
 		}
 	}

 	seq_puts(seq, "\n");

 	/* not really stopped, more like last-running-at */
 	stopped = pkt_dev->running ? ktime_get() : pkt_dev->stopped_at;
 	idle = pkt_dev->idle_acc;
 	do_div(idle, NSEC_PER_USEC);

 	seq_printf(seq,
 		   "Current:\n     pkts-sofar: %llu  errors: %llu\n",
 		   (unsigned long long)pkt_dev->sofar,
 		   (unsigned long long)pkt_dev->errors);

 	if (pkt_dev->n_imix_entries > 0) {
 		int i;

 		seq_puts(seq, "     imix_size_counts: ");
 		for (i = 0; i < pkt_dev->n_imix_entries; i++) {
 			seq_printf(seq, "%llu,%llu ",
 				   pkt_dev->imix_entries[i].size,
 				   pkt_dev->imix_entries[i].count_so_far);
 		}
 		seq_puts(seq, "\n");
 	}

 	seq_printf(seq,
 		   "     started: %lluus  stopped: %lluus idle: %lluus\n",
 		   (unsigned long long) ktime_to_us(pkt_dev->started_at),
 		   (unsigned long long) ktime_to_us(stopped),
 		   (unsigned long long) idle);

 	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) {
 		seq_printf(seq, "     cur_saddr: %pI6c  cur_daddr: %pI6c\n",
 				&pkt_dev->cur_in6_saddr,
 				&pkt_dev->cur_in6_daddr);
 	} else
 		seq_printf(seq, "     cur_saddr: %pI4  cur_daddr: %pI4\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, "     cur_queue_map: %u\n", pkt_dev->cur_queue_map);

 	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_puts(seq, "Result: Idle\n");

 	return 0;
 }


 static int hex32_arg(const char __user *user_buffer, unsigned long maxlen,
 		     __u32 *num)
 {
 	int i = 0;
 	*num = 0;

 	for (; i < maxlen; i++) {
 		int value;
 		char c;
 		*num <<= 4;
 		if (get_user(c, &user_buffer[i]))
 			return -EFAULT;
 		value = hex_to_bin(c);
 		if (value >= 0)
 			*num |= value;
 		else
 			break;
 	}
 	return i;
 }

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

 	for (i = 0; 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;

 	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 ' ':
 			goto done_str;
 		default:
 			break;
 		}
 	}
 done_str:
 	return i;
 }

 /* Parses imix entries from user buffer.
  * The user buffer should consist of imix entries separated by spaces
  * where each entry consists of size and weight delimited by commas.
  * "size1,weight_1 size2,weight_2 ... size_n,weight_n" for example.
  */
 static ssize_t get_imix_entries(const char __user *buffer,
 				struct pktgen_dev *pkt_dev)
 {
 	const int max_digits = 10;
 	int i = 0;
 	long len;
 	char c;

 	pkt_dev->n_imix_entries = 0;

 	do {
 		unsigned long weight;
 		unsigned long size;

 		len = num_arg(&buffer[i], max_digits, &size);
 		if (len < 0)
 			return len;
 		i += len;
 		if (get_user(c, &buffer[i]))
 			return -EFAULT;
 		/* Check for comma between size_i and weight_i */
 		if (c != ',')
 			return -EINVAL;
 		i++;

 		if (size < 14 + 20 + 8)
 			size = 14 + 20 + 8;

 		len = num_arg(&buffer[i], max_digits, &weight);
 		if (len < 0)
 			return len;
 		if (weight <= 0)
 			return -EINVAL;

 		pkt_dev->imix_entries[pkt_dev->n_imix_entries].size = size;
 		pkt_dev->imix_entries[pkt_dev->n_imix_entries].weight = weight;

 		i += len;
 		if (get_user(c, &buffer[i]))
 			return -EFAULT;

 		i++;
 		pkt_dev->n_imix_entries++;

 		if (pkt_dev->n_imix_entries > MAX_IMIX_ENTRIES)
 			return -E2BIG;
 	} while (c == ' ');

 	return i;
 }

 static ssize_t get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev)
 {
 	unsigned int n = 0;
 	char c;
 	ssize_t i = 0;
 	int len;

 	pkt_dev->nr_labels = 0;
 	do {
 		__u32 tmp;
 		len = hex32_arg(&buffer[i], 8, &tmp);
 		if (len <= 0)
 			return len;
 		pkt_dev->labels[n] = htonl(tmp);
 		if (pkt_dev->labels[n] & MPLS_STACK_BOTTOM)
 			pkt_dev->flags |= F_MPLS_RND;
 		i += len;
 		if (get_user(c, &buffer[i]))
 			return -EFAULT;
 		i++;
 		n++;
 		if (n >= MAX_MPLS_LABELS)
 			return -E2BIG;
 	} while (c == ',');

 	pkt_dev->nr_labels = n;
 	return i;
 }

 static __u32 pktgen_read_flag(const char *f, bool *disable)
 {
 	__u32 i;

 	if (f[0] == '!') {
 		*disable = true;
 		f++;
 	}

 	for (i = 0; i < NR_PKT_FLAGS; i++) {
 		if (!IS_ENABLED(CONFIG_XFRM) && i == IPSEC_SHIFT)
 			continue;

 		/* allow only disabling ipv6 flag */
 		if (!*disable && i == IPV6_SHIFT)
 			continue;

 		if (strcmp(f, pkt_flag_names[i]) == 0)
 			return 1 << i;
 	}

 	if (strcmp(f, "FLOW_RND") == 0) {
 		*disable = !*disable;
 		return F_FLOW_SEQ;
 	}

 	return 0;
 }

 static ssize_t pktgen_if_write(struct file *file,
 			       const char __user * user_buffer, size_t count,
 			       loff_t * offset)
 {
 	struct seq_file *seq = file->private_data;
 	struct pktgen_dev *pkt_dev = seq->private;
 	int i, 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) {
 		pr_warn("wrong command format\n");
 		return -EINVAL;
 	}

 	max = count;
 	tmp = count_trail_chars(user_buffer, max);
 	if (tmp < 0) {
 		pr_warn("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) {
 		size_t copy = min_t(size_t, count + 1, 1024);
 		char *tp = strndup_user(user_buffer, copy);

 		if (IS_ERR(tp))
 			return PTR_ERR(tp);

 		pr_debug("%s,%zu  buffer -:%s:-\n", name, count, tp);
 		kfree(tp);
 	}

 	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=%d",
 			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=%d",
 			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=%d", pkt_dev->min_pkt_size);
 		return count;
 	}

 	if (!strcmp(name, "imix_weights")) {
 		if (pkt_dev->clone_skb > 0)
 			return -EINVAL;

 		len = get_imix_entries(&user_buffer[i], pkt_dev);
 		if (len < 0)
 			return len;

 		fill_imix_distribution(pkt_dev);

 		i += len;
 		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=%d", 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 = ULLONG_MAX;
 		else
 			pkt_dev->delay = (u64)value;

 		sprintf(pg_result, "OK: delay=%llu",
 			(unsigned long long) pkt_dev->delay);
 		return count;
 	}
 	if (!strcmp(name, "rate")) {
 		len = num_arg(&user_buffer[i], 10, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if (!value)
 			return len;
 		pkt_dev->delay = pkt_dev->min_pkt_size*8*NSEC_PER_USEC/value;
 		if (debug)
 			pr_info("Delay set at: %llu ns\n", pkt_dev->delay);

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

 		i += len;
 		if (!value)
 			return len;
 		pkt_dev->delay = NSEC_PER_SEC/value;
 		if (debug)
 			pr_info("Delay set at: %llu ns\n", pkt_dev->delay);

 		sprintf(pg_result, "OK: rate=%lu", value);
 		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;
 		/* clone_skb is not supported for netif_receive xmit_mode and
 		 * IMIX mode.
 		 */
 		if ((value > 0) &&
 		    ((pkt_dev->xmit_mode == M_NETIF_RECEIVE) ||
 		     !(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
 			return -ENOTSUPP;
 		if (value > 0 && (pkt_dev->n_imix_entries > 0 ||
 				  !(pkt_dev->flags & F_SHARED)))
 			return -EINVAL;

 		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, "burst")) {
 		len = num_arg(&user_buffer[i], 10, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if ((value > 1) &&
 		    ((pkt_dev->xmit_mode == M_QUEUE_XMIT) ||
 		     ((pkt_dev->xmit_mode == M_START_XMIT) &&
 		     (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))))
 			return -ENOTSUPP;

 		if (value > 1 && !(pkt_dev->flags & F_SHARED))
 			return -EINVAL;

 		pkt_dev->burst = value < 1 ? 1 : value;
 		sprintf(pg_result, "OK: burst=%u", pkt_dev->burst);
 		return count;
 	}
 	if (!strcmp(name, "node")) {
 		len = num_arg(&user_buffer[i], 10, &value);
 		if (len < 0)
 			return len;

 		i += len;

 		if (node_possible(value)) {
 			pkt_dev->node = value;
 			sprintf(pg_result, "OK: node=%d", pkt_dev->node);
 			if (pkt_dev->page) {
 				put_page(pkt_dev->page);
 				pkt_dev->page = NULL;
 			}
 		}
 		else
 			sprintf(pg_result, "ERROR: node not possible");
 		return count;
 	}
 	if (!strcmp(name, "xmit_mode")) {
 		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, "start_xmit") == 0) {
 			pkt_dev->xmit_mode = M_START_XMIT;
 		} else if (strcmp(f, "netif_receive") == 0) {
 			/* clone_skb set earlier, not supported in this mode */
 			if (pkt_dev->clone_skb > 0)
 				return -ENOTSUPP;

 			pkt_dev->xmit_mode = M_NETIF_RECEIVE;

 			/* make sure new packet is allocated every time
 			 * pktgen_xmit() is called
 			 */
 			pkt_dev->last_ok = 1;
 		} else if (strcmp(f, "queue_xmit") == 0) {
 			pkt_dev->xmit_mode = M_QUEUE_XMIT;
 			pkt_dev->last_ok = 1;
 		} else {
 			sprintf(pg_result,
 				"xmit_mode -:%s:- unknown\nAvailable modes: %s",
 				f, "start_xmit, netif_receive\n");
 			return count;
 		}
 		sprintf(pg_result, "OK: xmit_mode=%s", f);
 		return count;
 	}
 	if (!strcmp(name, "flag")) {
 		bool disable = false;
 		__u32 flag;
 		char f[32];
 		char *end;

 		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;

 		flag = pktgen_read_flag(f, &disable);
 		if (flag) {
 			if (disable) {
 				/* If "clone_skb", or "burst" parameters are
 				 * configured, it means that the skb still
 				 * needs to be referenced by the pktgen, so
 				 * the skb must be shared.
 				 */
 				if (flag == F_SHARED && (pkt_dev->clone_skb ||
 							 pkt_dev->burst > 1))
 					return -EINVAL;
 				pkt_dev->flags &= ~flag;
 			} else {
 				pkt_dev->flags |= flag;
 			}

 			sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
 			return count;
 		}

 		/* Unknown flag */
 		end = pkt_dev->result + sizeof(pkt_dev->result);
 		pg_result += sprintf(pg_result,
 			"Flag -:%s:- unknown\n"
 			"Available flags, (prepend ! to un-set flag):\n", f);

 		for (int n = 0; n < NR_PKT_FLAGS && pg_result < end; n++) {
 			if (!IS_ENABLED(CONFIG_XFRM) && n == IPSEC_SHIFT)
 				continue;
 			pg_result += snprintf(pg_result, end - pg_result,
 					      "%s, ", pkt_flag_names[n]);
 		}
 		if (!WARN_ON_ONCE(pg_result >= end)) {
 			/* Remove the comma and whitespace at the end */
 			*(pg_result - 2) = '\0';
 		}

 		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));
 			strcpy(pkt_dev->dst_min, buf);
 			pkt_dev->daddr_min = in_aton(pkt_dev->dst_min);
 			pkt_dev->cur_daddr = pkt_dev->daddr_min;
 		}
 		if (debug)
 			pr_debug("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));
 			strcpy(pkt_dev->dst_max, buf);
 			pkt_dev->daddr_max = in_aton(pkt_dev->dst_max);
 			pkt_dev->cur_daddr = pkt_dev->daddr_max;
 		}
 		if (debug)
 			pr_debug("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;

 		in6_pton(buf, -1, pkt_dev->in6_daddr.s6_addr, -1, NULL);
 		snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->in6_daddr);

 		pkt_dev->cur_in6_daddr = pkt_dev->in6_daddr;

 		if (debug)
 			pr_debug("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;

 		in6_pton(buf, -1, pkt_dev->min_in6_daddr.s6_addr, -1, NULL);
 		snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->min_in6_daddr);

 		pkt_dev->cur_in6_daddr = pkt_dev->min_in6_daddr;
 		if (debug)
 			pr_debug("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;

 		in6_pton(buf, -1, pkt_dev->max_in6_daddr.s6_addr, -1, NULL);
 		snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->max_in6_daddr);

 		if (debug)
 			pr_debug("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;

 		in6_pton(buf, -1, pkt_dev->in6_saddr.s6_addr, -1, NULL);
 		snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->in6_saddr);

 		pkt_dev->cur_in6_saddr = pkt_dev->in6_saddr;

 		if (debug)
 			pr_debug("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));
 			strcpy(pkt_dev->src_min, buf);
 			pkt_dev->saddr_min = in_aton(pkt_dev->src_min);
 			pkt_dev->cur_saddr = pkt_dev->saddr_min;
 		}
 		if (debug)
 			pr_debug("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));
 			strcpy(pkt_dev->src_max, buf);
 			pkt_dev->saddr_max = in_aton(pkt_dev->src_max);
 			pkt_dev->cur_saddr = pkt_dev->saddr_max;
 		}
 		if (debug)
 			pr_debug("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")) {
 		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;

 		if (!mac_pton(valstr, pkt_dev->dst_mac))
 			return -EINVAL;
 		/* Set up Dest MAC */
 		ether_addr_copy(&pkt_dev->hh[0], pkt_dev->dst_mac);

 		sprintf(pg_result, "OK: dstmac %pM", pkt_dev->dst_mac);
 		return count;
 	}
 	if (!strcmp(name, "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;

 		if (!mac_pton(valstr, pkt_dev->src_mac))
 			return -EINVAL;
 		/* Set up Src MAC */
 		ether_addr_copy(&pkt_dev->hh[6], pkt_dev->src_mac);

 		sprintf(pg_result, "OK: srcmac %pM", pkt_dev->src_mac);
 		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;
 	}
 #ifdef CONFIG_XFRM
 	if (!strcmp(name, "spi")) {
 		len = num_arg(&user_buffer[i], 10, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		pkt_dev->spi = value;
 		sprintf(pg_result, "OK: spi=%u", pkt_dev->spi);
 		return count;
 	}
 #endif
 	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;
 	}

 	if (!strcmp(name, "queue_map_min")) {
 		len = num_arg(&user_buffer[i], 5, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		pkt_dev->queue_map_min = value;
 		sprintf(pg_result, "OK: queue_map_min=%u", pkt_dev->queue_map_min);
 		return count;
 	}

 	if (!strcmp(name, "queue_map_max")) {
 		len = num_arg(&user_buffer[i], 5, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		pkt_dev->queue_map_max = value;
 		sprintf(pg_result, "OK: queue_map_max=%u", pkt_dev->queue_map_max);
 		return count;
 	}

 	if (!strcmp(name, "mpls")) {
 		unsigned int n, cnt;

 		len = get_labels(&user_buffer[i], pkt_dev);
 		if (len < 0)
 			return len;
 		i += len;
 		cnt = sprintf(pg_result, "OK: mpls=");
 		for (n = 0; n < pkt_dev->nr_labels; n++)
 			cnt += sprintf(pg_result + cnt,
 				       "%08x%s", ntohl(pkt_dev->labels[n]),
 				       n == pkt_dev->nr_labels-1 ? "" : ",");

 		if (pkt_dev->nr_labels && pkt_dev->vlan_id != 0xffff) {
 			pkt_dev->vlan_id = 0xffff; /* turn off VLAN/SVLAN */
 			pkt_dev->svlan_id = 0xffff;

 			if (debug)
 				pr_debug("VLAN/SVLAN auto turned off\n");
 		}
 		return count;
 	}

 	if (!strcmp(name, "vlan_id")) {
 		len = num_arg(&user_buffer[i], 4, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if (value <= 4095) {
 			pkt_dev->vlan_id = value;  /* turn on VLAN */

 			if (debug)
 				pr_debug("VLAN turned on\n");

 			if (debug && pkt_dev->nr_labels)
 				pr_debug("MPLS auto turned off\n");

 			pkt_dev->nr_labels = 0;    /* turn off MPLS */
 			sprintf(pg_result, "OK: vlan_id=%u", pkt_dev->vlan_id);
 		} else {
 			pkt_dev->vlan_id = 0xffff; /* turn off VLAN/SVLAN */
 			pkt_dev->svlan_id = 0xffff;

 			if (debug)
 				pr_debug("VLAN/SVLAN turned off\n");
 		}
 		return count;
 	}

 	if (!strcmp(name, "vlan_p")) {
 		len = num_arg(&user_buffer[i], 1, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if ((value <= 7) && (pkt_dev->vlan_id != 0xffff)) {
 			pkt_dev->vlan_p = value;
 			sprintf(pg_result, "OK: vlan_p=%u", pkt_dev->vlan_p);
 		} else {
 			sprintf(pg_result, "ERROR: vlan_p must be 0-7");
 		}
 		return count;
 	}

 	if (!strcmp(name, "vlan_cfi")) {
 		len = num_arg(&user_buffer[i], 1, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if ((value <= 1) && (pkt_dev->vlan_id != 0xffff)) {
 			pkt_dev->vlan_cfi = value;
 			sprintf(pg_result, "OK: vlan_cfi=%u", pkt_dev->vlan_cfi);
 		} else {
 			sprintf(pg_result, "ERROR: vlan_cfi must be 0-1");
 		}
 		return count;
 	}

 	if (!strcmp(name, "svlan_id")) {
 		len = num_arg(&user_buffer[i], 4, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if ((value <= 4095) && ((pkt_dev->vlan_id != 0xffff))) {
 			pkt_dev->svlan_id = value;  /* turn on SVLAN */

 			if (debug)
 				pr_debug("SVLAN turned on\n");

 			if (debug && pkt_dev->nr_labels)
 				pr_debug("MPLS auto turned off\n");

 			pkt_dev->nr_labels = 0;    /* turn off MPLS */
 			sprintf(pg_result, "OK: svlan_id=%u", pkt_dev->svlan_id);
 		} else {
 			pkt_dev->vlan_id = 0xffff; /* turn off VLAN/SVLAN */
 			pkt_dev->svlan_id = 0xffff;

 			if (debug)
 				pr_debug("VLAN/SVLAN turned off\n");
 		}
 		return count;
 	}

 	if (!strcmp(name, "svlan_p")) {
 		len = num_arg(&user_buffer[i], 1, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if ((value <= 7) && (pkt_dev->svlan_id != 0xffff)) {
 			pkt_dev->svlan_p = value;
 			sprintf(pg_result, "OK: svlan_p=%u", pkt_dev->svlan_p);
 		} else {
 			sprintf(pg_result, "ERROR: svlan_p must be 0-7");
 		}
 		return count;
 	}

 	if (!strcmp(name, "svlan_cfi")) {
 		len = num_arg(&user_buffer[i], 1, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		if ((value <= 1) && (pkt_dev->svlan_id != 0xffff)) {
 			pkt_dev->svlan_cfi = value;
 			sprintf(pg_result, "OK: svlan_cfi=%u", pkt_dev->svlan_cfi);
 		} else {
 			sprintf(pg_result, "ERROR: svlan_cfi must be 0-1");
 		}
 		return count;
 	}

 	if (!strcmp(name, "tos")) {
 		__u32 tmp_value = 0;
 		len = hex32_arg(&user_buffer[i], 2, &tmp_value);
 		if (len < 0)
 			return len;

 		i += len;
 		if (len == 2) {
 			pkt_dev->tos = tmp_value;
 			sprintf(pg_result, "OK: tos=0x%02x", pkt_dev->tos);
 		} else {
 			sprintf(pg_result, "ERROR: tos must be 00-ff");
 		}
 		return count;
 	}

 	if (!strcmp(name, "traffic_class")) {
 		__u32 tmp_value = 0;
 		len = hex32_arg(&user_buffer[i], 2, &tmp_value);
 		if (len < 0)
 			return len;

 		i += len;
 		if (len == 2) {
 			pkt_dev->traffic_class = tmp_value;
 			sprintf(pg_result, "OK: traffic_class=0x%02x", pkt_dev->traffic_class);
 		} else {
 			sprintf(pg_result, "ERROR: traffic_class must be 00-ff");
 		}
 		return count;
 	}

 	if (!strcmp(name, "skb_priority")) {
 		len = num_arg(&user_buffer[i], 9, &value);
 		if (len < 0)
 			return len;

 		i += len;
 		pkt_dev->skb_priority = value;
 		sprintf(pg_result, "OK: skb_priority=%i",
 			pkt_dev->skb_priority);
 		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_data(inode));
 }

 static const struct proc_ops pktgen_if_proc_ops = {
 	.proc_open	= pktgen_if_open,
 	.proc_read	= seq_read,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= pktgen_if_write,
 	.proc_release	= single_release,
 };

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

 	BUG_ON(!t);

 	seq_puts(seq, "Running: ");

 	rcu_read_lock();
 	list_for_each_entry_rcu(pkt_dev, &t->if_list, list)
 		if (pkt_dev->running)
 			seq_printf(seq, "%s ", pkt_dev->odevname);

 	seq_puts(seq, "\nStopped: ");

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

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

 	rcu_read_unlock();

 	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 = file->private_data;
 	struct pktgen_thread *t = seq->private;
 	int i, max, len, ret;
 	char name[40];
 	char *pg_result;

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

 	max = count;
 	len = count_trail_chars(user_buffer, 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)
 		pr_debug("t=%s, count=%lu\n", name, (unsigned long)count);

 	if (!t) {
 		pr_err("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);
 		ret = pktgen_add_device(t, f);
 		mutex_unlock(&pktgen_thread_lock);
 		if (!ret) {
 			ret = count;
 			sprintf(pg_result, "OK: add_device=%s", f);
 		} else
 			sprintf(pg_result, "ERROR: can not 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")) {
 		sprintf(pg_result, "OK: Note! max_before_softirq is obsoleted -- Do not use");
 		ret = count;
 		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_data(inode));
 }

 static const struct proc_ops pktgen_thread_proc_ops = {
 	.proc_open	= pktgen_thread_open,
 	.proc_read	= seq_read,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= pktgen_thread_write,
 	.proc_release	= single_release,
 };

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

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

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

 	mutex_lock(&pktgen_thread_lock);
 	pr_debug("%s: marking %s for removal\n", __func__, ifname);

 	while (1) {

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

 		mutex_unlock(&pktgen_thread_lock);
 		pr_debug("%s: waiting for %s to disappear....\n",
 			 __func__, ifname);
 		schedule_timeout_interruptible(msecs_to_jiffies(msec_per_try));
 		mutex_lock(&pktgen_thread_lock);

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

 	}

 	mutex_unlock(&pktgen_thread_lock);
 }

 static void pktgen_change_name(const struct pktgen_net *pn, struct net_device *dev)
 {
 	struct pktgen_thread *t;

 	mutex_lock(&pktgen_thread_lock);

 	list_for_each_entry(t, &pn->pktgen_threads, th_list) {
 		struct pktgen_dev *pkt_dev;

 		if_lock(t);
 		list_for_each_entry(pkt_dev, &t->if_list, list) {
 			if (pkt_dev->odev != dev)
 				continue;

 			proc_remove(pkt_dev->entry);

 			pkt_dev->entry = proc_create_data(dev->name, 0600,
 							  pn->proc_dir,
 							  &pktgen_if_proc_ops,
 							  pkt_dev);
 			if (!pkt_dev->entry)
 				pr_err("can't move proc entry for '%s'\n",
 				       dev->name);
 			break;
 		}
 		if_unlock(t);
 	}
 	mutex_unlock(&pktgen_thread_lock);
 }

 static int pktgen_device_event(struct notifier_block *unused,
 			       unsigned long event, void *ptr)
 {
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct pktgen_net *pn = net_generic(dev_net(dev), pg_net_id);

 	if (pn->pktgen_exiting)
 		return NOTIFY_DONE;

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

 	switch (event) {
 	case NETDEV_CHANGENAME:
 		pktgen_change_name(pn, dev);
 		break;

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

 	return NOTIFY_DONE;
 }

 static struct net_device *pktgen_dev_get_by_name(const struct pktgen_net *pn,
 						 struct pktgen_dev *pkt_dev,
 						 const char *ifname)
 {
 	char b[IFNAMSIZ+5];
 	int i;

 	for (i = 0; ifname[i] != '@'; i++) {
 		if (i == IFNAMSIZ)
 			break;

 		b[i] = ifname[i];
 	}
 	b[i] = 0;

 	return dev_get_by_name(pn->net, b);
 }


 /* Associate pktgen_dev with a device. */

 static int pktgen_setup_dev(const struct pktgen_net *pn,
 			    struct pktgen_dev *pkt_dev, const char *ifname)
 {
 	struct net_device *odev;
 	int err;

 	/* Clean old setups */
 	if (pkt_dev->odev) {
 		netdev_put(pkt_dev->odev, &pkt_dev->dev_tracker);
 		pkt_dev->odev = NULL;
 	}

 	odev = pktgen_dev_get_by_name(pn, pkt_dev, ifname);
 	if (!odev) {
 		pr_err("no such netdevice: \"%s\"\n", ifname);
 		return -ENODEV;
 	}

 	if (odev->type != ARPHRD_ETHER && odev->type != ARPHRD_LOOPBACK) {
 		pr_err("not an ethernet or loopback device: \"%s\"\n", ifname);
 		err = -EINVAL;
 	} else if (!netif_running(odev)) {
 		pr_err("device is down: \"%s\"\n", ifname);
 		err = -ENETDOWN;
 	} else {
 		pkt_dev->odev = odev;
 		netdev_tracker_alloc(odev, &pkt_dev->dev_tracker, GFP_KERNEL);
 		return 0;
 	}

 	dev_put(odev);
 	return err;
 }

 /* 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)
 {
 	int ntxq;

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

 	/* make sure that we don't pick a non-existing transmit queue */
 	ntxq = pkt_dev->odev->real_num_tx_queues;

 	if (ntxq <= pkt_dev->queue_map_min) {
 		pr_warn("WARNING: Requested queue_map_min (zero-based) (%d) exceeds valid range [0 - %d] for (%d) queues on %s, resetting\n",
 			pkt_dev->queue_map_min, (ntxq ?: 1) - 1, ntxq,
 			pkt_dev->odevname);
 		pkt_dev->queue_map_min = (ntxq ?: 1) - 1;
 	}
 	if (pkt_dev->queue_map_max >= ntxq) {
 		pr_warn("WARNING: Requested queue_map_max (zero-based) (%d) exceeds valid range [0 - %d] for (%d) queues on %s, resetting\n",
 			pkt_dev->queue_map_max, (ntxq ?: 1) - 1, ntxq,
 			pkt_dev->odevname);
 		pkt_dev->queue_map_max = (ntxq ?: 1) - 1;
 	}

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

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

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

 	if (pkt_dev->flags & F_IPV6) {
 		int i, set = 0, err = 1;
 		struct inet6_dev *idev;

 		if (pkt_dev->min_pkt_size == 0) {
 			pkt_dev->min_pkt_size = 14 + sizeof(struct ipv6hdr)
 						+ sizeof(struct udphdr)
 						+ sizeof(struct pktgen_hdr)
 						+ pkt_dev->pkt_overhead;
 		}

 		for (i = 0; i < sizeof(struct in6_addr); 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
 			 */

 			rcu_read_lock();
 			idev = __in6_dev_get(pkt_dev->odev);
 			if (idev) {
 				struct inet6_ifaddr *ifp;

 				read_lock_bh(&idev->lock);
 				list_for_each_entry(ifp, &idev->addr_list, if_list) {
 					if ((ifp->scope & IFA_LINK) &&
 					    !(ifp->flags & IFA_F_TENTATIVE)) {
 						pkt_dev->cur_in6_saddr = ifp->addr;
 						err = 0;
 						break;
 					}
 				}
 				read_unlock_bh(&idev->lock);
 			}
 			rcu_read_unlock();
 			if (err)
 				pr_err("ERROR: IPv6 link address not available\n");
 		}
 	} else {
 		if (pkt_dev->min_pkt_size == 0) {
 			pkt_dev->min_pkt_size = 14 + sizeof(struct iphdr)
 						+ sizeof(struct udphdr)
 						+ sizeof(struct pktgen_hdr)
 						+ pkt_dev->pkt_overhead;
 		}

 		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) {
 				const struct in_ifaddr *ifa;

 				ifa = rcu_dereference(in_dev->ifa_list);
 				if (ifa) {
 					pkt_dev->saddr_min = ifa->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_pkt_size = pkt_dev->min_pkt_size;
 	if (pkt_dev->min_pkt_size > pkt_dev->max_pkt_size)
 		pkt_dev->max_pkt_size = pkt_dev->min_pkt_size;

 	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, ktime_t spin_until)
 {
 	ktime_t start_time, end_time;
 	s64 remaining;
 	struct hrtimer_sleeper t;

 	hrtimer_init_sleeper_on_stack(&t, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 	hrtimer_set_expires(&t.timer, spin_until);

 	remaining = ktime_to_ns(hrtimer_expires_remaining(&t.timer));
 	if (remaining <= 0)
 		goto out;

 	start_time = ktime_get();
 	if (remaining < 100000) {
 		/* for small delays (<100us), just loop until limit is reached */
 		do {
 			end_time = ktime_get();
 		} while (ktime_compare(end_time, spin_until) < 0);
 	} else {
 		do {
 			set_current_state(TASK_INTERRUPTIBLE);
 			hrtimer_sleeper_start_expires(&t, HRTIMER_MODE_ABS);

 			if (likely(t.task))
 				schedule();

 			hrtimer_cancel(&t.timer);
 		} while (t.task && pkt_dev->running && !signal_pending(current));
 		__set_current_state(TASK_RUNNING);
 		end_time = ktime_get();
 	}

 	pkt_dev->idle_acc += ktime_to_ns(ktime_sub(end_time, start_time));
 out:
 	pkt_dev->next_tx = ktime_add_ns(spin_until, pkt_dev->delay);
 	destroy_hrtimer_on_stack(&t.timer);
 }

 static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev)
 {
 	pkt_dev->pkt_overhead = 0;
 	pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32);
 	pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev);
 	pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev);
 }

 static inline int f_seen(const struct pktgen_dev *pkt_dev, int flow)
 {
 	return !!(pkt_dev->flows[flow].flags & F_INIT);
 }

 static inline int f_pick(struct pktgen_dev *pkt_dev)
 {
 	int flow = pkt_dev->curfl;

 	if (pkt_dev->flags & F_FLOW_SEQ) {
 		if (pkt_dev->flows[flow].count >= pkt_dev->lflow) {
 			/* reset time */
 			pkt_dev->flows[flow].count = 0;
 			pkt_dev->flows[flow].flags = 0;
 			pkt_dev->curfl += 1;
 			if (pkt_dev->curfl >= pkt_dev->cflows)
 				pkt_dev->curfl = 0; /*reset */
 		}
 	} else {
 		flow = get_random_u32_below(pkt_dev->cflows);
 		pkt_dev->curfl = flow;

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

 	return pkt_dev->curfl;
 }


 #ifdef CONFIG_XFRM
 /* If there was already an IPSEC SA, we keep it as is, else
  * we go look for it ...
 */
 #define DUMMY_MARK 0
 static void get_ipsec_sa(struct pktgen_dev *pkt_dev, int flow)
 {
 	struct xfrm_state *x = pkt_dev->flows[flow].x;
 	struct pktgen_net *pn = net_generic(dev_net(pkt_dev->odev), pg_net_id);
 	if (!x) {

 		if (pkt_dev->spi) {
 			/* We need as quick as possible to find the right SA
 			 * Searching with minimum criteria to archieve this.
 			 */
 			x = xfrm_state_lookup_byspi(pn->net, htonl(pkt_dev->spi), AF_INET);
 		} else {
 			/* slow path: we dont already have xfrm_state */
 			x = xfrm_stateonly_find(pn->net, DUMMY_MARK, 0,
 						(xfrm_address_t *)&pkt_dev->cur_daddr,
 						(xfrm_address_t *)&pkt_dev->cur_saddr,
 						AF_INET,
 						pkt_dev->ipsmode,
 						pkt_dev->ipsproto, 0);
 		}
 		if (x) {
 			pkt_dev->flows[flow].x = x;
 			set_pkt_overhead(pkt_dev);
 			pkt_dev->pkt_overhead += x->props.header_len;
 		}

 	}
 }
 #endif
 static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
 {

 	if (pkt_dev->flags & F_QUEUE_MAP_CPU)
 		pkt_dev->cur_queue_map = smp_processor_id();

 	else if (pkt_dev->queue_map_min <= pkt_dev->queue_map_max) {
 		__u16 t;
 		if (pkt_dev->flags & F_QUEUE_MAP_RND) {
 			t = get_random_u32_inclusive(pkt_dev->queue_map_min,
 						     pkt_dev->queue_map_max);
 		} else {
 			t = pkt_dev->cur_queue_map + 1;
 			if (t > pkt_dev->queue_map_max)
 				t = pkt_dev->queue_map_min;
 		}
 		pkt_dev->cur_queue_map = t;
 	}
 	pkt_dev->cur_queue_map  = pkt_dev->cur_queue_map % pkt_dev->odev->real_num_tx_queues;
 }

 /* 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 = f_pick(pkt_dev);

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

 		if (pkt_dev->flags & F_MACSRC_RND)
 			mc = get_random_u32_below(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 = get_random_u32_below(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->flags & F_MPLS_RND) {
 		unsigned int i;
 		for (i = 0; i < pkt_dev->nr_labels; i++)
 			if (pkt_dev->labels[i] & MPLS_STACK_BOTTOM)
 				pkt_dev->labels[i] = MPLS_STACK_BOTTOM |
 					     ((__force __be32)get_random_u32() &
 						      htonl(0x000fffff));
 	}

 	if ((pkt_dev->flags & F_VID_RND) && (pkt_dev->vlan_id != 0xffff)) {
 		pkt_dev->vlan_id = get_random_u32_below(4096);
 	}

 	if ((pkt_dev->flags & F_SVID_RND) && (pkt_dev->svlan_id != 0xffff)) {
 		pkt_dev->svlan_id = get_random_u32_below(4096);
 	}

 	if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
 		if (pkt_dev->flags & F_UDPSRC_RND)
 			pkt_dev->cur_udp_src = get_random_u32_inclusive(pkt_dev->udp_src_min,
 									pkt_dev->udp_src_max - 1);

 		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 = get_random_u32_inclusive(pkt_dev->udp_dst_min,
 									pkt_dev->udp_dst_max - 1);
 		} 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)) {

 		imn = ntohl(pkt_dev->saddr_min);
 		imx = ntohl(pkt_dev->saddr_max);
 		if (imn < imx) {
 			__u32 t;
 			if (pkt_dev->flags & F_IPSRC_RND)
 				t = get_random_u32_inclusive(imn, imx - 1);
 			else {
 				t = ntohl(pkt_dev->cur_saddr);
 				t++;
 				if (t > imx)
 					t = imn;

 			}
 			pkt_dev->cur_saddr = htonl(t);
 		}

 		if (pkt_dev->cflows && f_seen(pkt_dev, flow)) {
 			pkt_dev->cur_daddr = pkt_dev->flows[flow].cur_daddr;
 		} else {
 			imn = ntohl(pkt_dev->daddr_min);
 			imx = ntohl(pkt_dev->daddr_max);
 			if (imn < imx) {
 				__u32 t;
 				__be32 s;
 				if (pkt_dev->flags & F_IPDST_RND) {

 					do {
 						t = get_random_u32_inclusive(imn, imx - 1);
 						s = htonl(t);
 					} while (ipv4_is_loopback(s) ||
 						ipv4_is_multicast(s) ||
 						ipv4_is_lbcast(s) ||
 						ipv4_is_zeronet(s) ||
 						ipv4_is_local_multicast(s));
 					pkt_dev->cur_daddr = s;
 				} 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].flags |= F_INIT;
 				pkt_dev->flows[flow].cur_daddr =
 				    pkt_dev->cur_daddr;
 #ifdef CONFIG_XFRM
 				if (pkt_dev->flags & F_IPSEC)
 					get_ipsec_sa(pkt_dev, flow);
 #endif
 				pkt_dev->nflows++;
 			}
 		}
 	} else {		/* IPV6 * */

 		if (!ipv6_addr_any(&pkt_dev->min_in6_daddr)) {
 			int i;

 			/* Only random destinations yet */

 			for (i = 0; i < 4; i++) {
 				pkt_dev->cur_in6_daddr.s6_addr32[i] =
 				    (((__force __be32)get_random_u32() |
 				      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 = get_random_u32_inclusive(pkt_dev->min_pkt_size,
 						     pkt_dev->max_pkt_size - 1);
 		} 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;
 	} else if (pkt_dev->n_imix_entries > 0) {
 		struct imix_pkt *entry;
 		__u32 t = get_random_u32_below(IMIX_PRECISION);
 		__u8 entry_index = pkt_dev->imix_distribution[t];

 		entry = &pkt_dev->imix_entries[entry_index];
 		entry->count_so_far++;
 		pkt_dev->cur_pkt_size = entry->size;
 	}

 	set_cur_queue_map(pkt_dev);

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

 static void fill_imix_distribution(struct pktgen_dev *pkt_dev)
 {
 	int cumulative_probabilites[MAX_IMIX_ENTRIES];
 	int j = 0;
 	__u64 cumulative_prob = 0;
 	__u64 total_weight = 0;
 	int i = 0;

 	for (i = 0; i < pkt_dev->n_imix_entries; i++)
 		total_weight += pkt_dev->imix_entries[i].weight;

 	/* Fill cumulative_probabilites with sum of normalized probabilities */
 	for (i = 0; i < pkt_dev->n_imix_entries - 1; i++) {
 		cumulative_prob += div64_u64(pkt_dev->imix_entries[i].weight *
 						     IMIX_PRECISION,
 					     total_weight);
 		cumulative_probabilites[i] = cumulative_prob;
 	}
 	cumulative_probabilites[pkt_dev->n_imix_entries - 1] = 100;

 	for (i = 0; i < IMIX_PRECISION; i++) {
 		if (i == cumulative_probabilites[j])
 			j++;
 		pkt_dev->imix_distribution[i] = j;
 	}
 }

 #ifdef CONFIG_XFRM
 static u32 pktgen_dst_metrics[RTAX_MAX + 1] = {

 	[RTAX_HOPLIMIT] = 0x5, /* Set a static hoplimit */
 };

 static int pktgen_output_ipsec(struct sk_buff *skb, struct pktgen_dev *pkt_dev)
 {
 	struct xfrm_state *x = pkt_dev->flows[pkt_dev->curfl].x;
 	int err = 0;
 	struct net *net = dev_net(pkt_dev->odev);

 	if (!x)
 		return 0;
 	/* XXX: we dont support tunnel mode for now until
 	 * we resolve the dst issue */
 	if ((x->props.mode != XFRM_MODE_TRANSPORT) && (pkt_dev->spi == 0))
 		return 0;

 	/* But when user specify an valid SPI, transformation
 	 * supports both transport/tunnel mode + ESP/AH type.
 	 */
 	if ((x->props.mode == XFRM_MODE_TUNNEL) && (pkt_dev->spi != 0))
 		skb->_skb_refdst = (unsigned long)&pkt_dev->xdst.u.dst | SKB_DST_NOREF;

 	rcu_read_lock_bh();
 	err = pktgen_xfrm_outer_mode_output(x, skb);
 	rcu_read_unlock_bh();
 	if (err) {
 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
 		goto error;
 	}
 	err = x->type->output(x, skb);
 	if (err) {
 		XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
 		goto error;
 	}
 	spin_lock_bh(&x->lock);
 	x->curlft.bytes += skb->len;
 	x->curlft.packets++;
 	spin_unlock_bh(&x->lock);
 error:
 	return err;
 }

 static void free_SAs(struct pktgen_dev *pkt_dev)
 {
 	if (pkt_dev->cflows) {
 		/* let go of the SAs if we have them */
 		int i;
 		for (i = 0; i < pkt_dev->cflows; i++) {
 			struct xfrm_state *x = pkt_dev->flows[i].x;
 			if (x) {
 				xfrm_state_put(x);
 				pkt_dev->flows[i].x = NULL;
 			}
 		}
 	}
 }

 static int process_ipsec(struct pktgen_dev *pkt_dev,
 			      struct sk_buff *skb, __be16 protocol)
 {
 	if (pkt_dev->flags & F_IPSEC) {
 		struct xfrm_state *x = pkt_dev->flows[pkt_dev->curfl].x;
 		int nhead = 0;
 		if (x) {
 			struct ethhdr *eth;
 			struct iphdr *iph;
 			int ret;

 			nhead = x->props.header_len - skb_headroom(skb);
 			if (nhead > 0) {
 				ret = pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);
 				if (ret < 0) {
 					pr_err("Error expanding ipsec packet %d\n",
 					       ret);
 					goto err;
 				}
 			}

 			/* ipsec is not expecting ll header */
 			skb_pull(skb, ETH_HLEN);
 			ret = pktgen_output_ipsec(skb, pkt_dev);
 			if (ret) {
 				pr_err("Error creating ipsec packet %d\n", ret);
 				goto err;
 			}
 			/* restore ll */
 			eth = skb_push(skb, ETH_HLEN);
 			memcpy(eth, pkt_dev->hh, 2 * ETH_ALEN);
 			eth->h_proto = protocol;

 			/* Update IPv4 header len as well as checksum value */
 			iph = ip_hdr(skb);
 			iph->tot_len = htons(skb->len - ETH_HLEN);
 			ip_send_check(iph);
 		}
 	}
 	return 1;
 err:
 	kfree_skb(skb);
 	return 0;
 }
 #endif

 static void mpls_push(__be32 *mpls, struct pktgen_dev *pkt_dev)
 {
 	unsigned int i;
 	for (i = 0; i < pkt_dev->nr_labels; i++)
 		*mpls++ = pkt_dev->labels[i] & ~MPLS_STACK_BOTTOM;

 	mpls--;
 	*mpls |= MPLS_STACK_BOTTOM;
 }

 static inline __be16 build_tci(unsigned int id, unsigned int cfi,
 			       unsigned int prio)
 {
 	return htons(id | (cfi << 12) | (prio << 13));
 }

 static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb,
 				int datalen)
 {
 	struct timespec64 timestamp;
 	struct pktgen_hdr *pgh;

 	pgh = skb_put(skb, sizeof(*pgh));
 	datalen -= sizeof(*pgh);

 	if (pkt_dev->nfrags <= 0) {
 		skb_put_zero(skb, datalen);
 	} else {
 		int frags = pkt_dev->nfrags;
 		int i, len;
 		int frag_len;


 		if (frags > MAX_SKB_FRAGS)
 			frags = MAX_SKB_FRAGS;
 		len = datalen - frags * PAGE_SIZE;
 		if (len > 0) {
 			skb_put_zero(skb, len);
 			datalen = frags * PAGE_SIZE;
 		}

 		i = 0;
 		frag_len = (datalen/frags) < PAGE_SIZE ?
 			   (datalen/frags) : PAGE_SIZE;
 		while (datalen > 0) {
 			if (unlikely(!pkt_dev->page)) {
 				int node = numa_node_id();

 				if (pkt_dev->node >= 0 && (pkt_dev->flags & F_NODE))
 					node = pkt_dev->node;
 				pkt_dev->page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
 				if (!pkt_dev->page)
 					break;
 			}
 			get_page(pkt_dev->page);

 			/*last fragment, fill rest of data*/
 			if (i == (frags - 1))
 				skb_frag_fill_page_desc(&skb_shinfo(skb)->frags[i],
 							pkt_dev->page, 0,
 							(datalen < PAGE_SIZE ?
 							 datalen : PAGE_SIZE));
 			else
 				skb_frag_fill_page_desc(&skb_shinfo(skb)->frags[i],
 							pkt_dev->page, 0, frag_len);

 			datalen -= skb_frag_size(&skb_shinfo(skb)->frags[i]);
 			skb->len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
 			skb->data_len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
 			i++;
 			skb_shinfo(skb)->nr_frags = i;
 		}
 	}

 	/* Stamp the time, and sequence number,
 	 * convert them to network byte order
 	 */
 	pgh->pgh_magic = htonl(PKTGEN_MAGIC);
 	pgh->seq_num = htonl(pkt_dev->seq_num);

 	if (pkt_dev->flags & F_NO_TIMESTAMP) {
 		pgh->tv_sec = 0;
 		pgh->tv_usec = 0;
 	} else {
 		/*
 		 * pgh->tv_sec wraps in y2106 when interpreted as unsigned
 		 * as done by wireshark, or y2038 when interpreted as signed.
 		 * This is probably harmless, but if anyone wants to improve
 		 * it, we could introduce a variant that puts 64-bit nanoseconds
 		 * into the respective header bytes.
 		 * This would also be slightly faster to read.
 		 */
 		ktime_get_real_ts64(&timestamp);
 		pgh->tv_sec = htonl(timestamp.tv_sec);
 		pgh->tv_usec = htonl(timestamp.tv_nsec / NSEC_PER_USEC);
 	}
 }

 static struct sk_buff *pktgen_alloc_skb(struct net_device *dev,
 					struct pktgen_dev *pkt_dev)
 {
 	unsigned int extralen = LL_RESERVED_SPACE(dev);
 	struct sk_buff *skb = NULL;
 	unsigned int size;

 	size = pkt_dev->cur_pkt_size + 64 + extralen + pkt_dev->pkt_overhead;
 	if (pkt_dev->flags & F_NODE) {
 		int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id();

 		skb = __alloc_skb(NET_SKB_PAD + size, GFP_NOWAIT, 0, node);
 		if (likely(skb)) {
 			skb_reserve(skb, NET_SKB_PAD);
 			skb->dev = dev;
 		}
 	} else {
 		 skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT);
 	}

 	/* the caller pre-fetches from skb->data and reserves for the mac hdr */
 	if (likely(skb))
 		skb_reserve(skb, extralen - 16);

 	return skb;
 }

 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;
 	__be16 protocol = htons(ETH_P_IP);
 	__be32 *mpls;
 	__be16 *vlan_tci = NULL;                 /* Encapsulates priority and VLAN ID */
 	__be16 *vlan_encapsulated_proto = NULL;  /* packet type ID field (or len) for VLAN tag */
 	__be16 *svlan_tci = NULL;                /* Encapsulates priority and SVLAN ID */
 	__be16 *svlan_encapsulated_proto = NULL; /* packet type ID field (or len) for SVLAN tag */
 	u16 queue_map;

 	if (pkt_dev->nr_labels)
 		protocol = htons(ETH_P_MPLS_UC);

 	if (pkt_dev->vlan_id != 0xffff)
 		protocol = htons(ETH_P_8021Q);

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

 	skb = pktgen_alloc_skb(odev, pkt_dev);
 	if (!skb) {
 		sprintf(pkt_dev->result, "No memory");
 		return NULL;
 	}

 	prefetchw(skb->data);
 	skb_reserve(skb, 16);

 	/*  Reserve for ethernet and IP header  */
 	eth = skb_push(skb, 14);
 	mpls = skb_put(skb, pkt_dev->nr_labels * sizeof(__u32));
 	if (pkt_dev->nr_labels)
 		mpls_push(mpls, pkt_dev);

 	if (pkt_dev->vlan_id != 0xffff) {
 		if (pkt_dev->svlan_id != 0xffff) {
 			svlan_tci = skb_put(skb, sizeof(__be16));
 			*svlan_tci = build_tci(pkt_dev->svlan_id,
 					       pkt_dev->svlan_cfi,
 					       pkt_dev->svlan_p);
 			svlan_encapsulated_proto = skb_put(skb,
 							   sizeof(__be16));
 			*svlan_encapsulated_proto = htons(ETH_P_8021Q);
 		}
 		vlan_tci = skb_put(skb, sizeof(__be16));
 		*vlan_tci = build_tci(pkt_dev->vlan_id,
 				      pkt_dev->vlan_cfi,
 				      pkt_dev->vlan_p);
 		vlan_encapsulated_proto = skb_put(skb, sizeof(__be16));
 		*vlan_encapsulated_proto = htons(ETH_P_IP);
 	}

 	skb_reset_mac_header(skb);
 	skb_set_network_header(skb, skb->len);
 	iph = skb_put(skb, sizeof(struct iphdr));

 	skb_set_transport_header(skb, skb->len);
 	udph = skb_put(skb, sizeof(struct udphdr));
 	skb_set_queue_mapping(skb, queue_map);
 	skb->priority = pkt_dev->skb_priority;

 	memcpy(eth, pkt_dev->hh, 12);
 	*(__be16 *) & eth[12] = protocol;

 	/* Eth + IPh + UDPh + mpls */
 	datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 -
 		  pkt_dev->pkt_overhead;
 	if (datalen < 0 || 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;

 	iph->ihl = 5;
 	iph->version = 4;
 	iph->ttl = 32;
 	iph->tos = pkt_dev->tos;
 	iph->protocol = IPPROTO_UDP;	/* UDP */
 	iph->saddr = pkt_dev->cur_saddr;
 	iph->daddr = pkt_dev->cur_daddr;
 	iph->id = htons(pkt_dev->ip_id);
 	pkt_dev->ip_id++;
 	iph->frag_off = 0;
 	iplen = 20 + 8 + datalen;
 	iph->tot_len = htons(iplen);
 	ip_send_check(iph);
 	skb->protocol = protocol;
 	skb->dev = odev;
 	skb->pkt_type = PACKET_HOST;

 	pktgen_finalize_skb(pkt_dev, skb, datalen);

 	if (!(pkt_dev->flags & F_UDPCSUM)) {
 		skb->ip_summed = CHECKSUM_NONE;
 	} else if (odev->features & (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)) {
 		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb->csum = 0;
 		udp4_hwcsum(skb, iph->saddr, iph->daddr);
 	} else {
 		__wsum csum = skb_checksum(skb, skb_transport_offset(skb), datalen + 8, 0);

 		/* add protocol-dependent pseudo-header */
 		udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
 						datalen + 8, IPPROTO_UDP, csum);

 		if (udph->check == 0)
 			udph->check = CSUM_MANGLED_0;
 	}

 #ifdef CONFIG_XFRM
 	if (!process_ipsec(pkt_dev, skb, protocol))
 		return NULL;
 #endif

 	return skb;
 }

 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, udplen;
 	struct ipv6hdr *iph;
 	__be16 protocol = htons(ETH_P_IPV6);
 	__be32 *mpls;
 	__be16 *vlan_tci = NULL;                 /* Encapsulates priority and VLAN ID */
 	__be16 *vlan_encapsulated_proto = NULL;  /* packet type ID field (or len) for VLAN tag */
 	__be16 *svlan_tci = NULL;                /* Encapsulates priority and SVLAN ID */
 	__be16 *svlan_encapsulated_proto = NULL; /* packet type ID field (or len) for SVLAN tag */
 	u16 queue_map;

 	if (pkt_dev->nr_labels)
 		protocol = htons(ETH_P_MPLS_UC);

 	if (pkt_dev->vlan_id != 0xffff)
 		protocol = htons(ETH_P_8021Q);

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

 	skb = pktgen_alloc_skb(odev, pkt_dev);
 	if (!skb) {
 		sprintf(pkt_dev->result, "No memory");
 		return NULL;
 	}

 	prefetchw(skb->data);
 	skb_reserve(skb, 16);

 	/*  Reserve for ethernet and IP header  */
 	eth = skb_push(skb, 14);
 	mpls = skb_put(skb, pkt_dev->nr_labels * sizeof(__u32));
 	if (pkt_dev->nr_labels)
 		mpls_push(mpls, pkt_dev);

 	if (pkt_dev->vlan_id != 0xffff) {
 		if (pkt_dev->svlan_id != 0xffff) {
 			svlan_tci = skb_put(skb, sizeof(__be16));
 			*svlan_tci = build_tci(pkt_dev->svlan_id,
 					       pkt_dev->svlan_cfi,
 					       pkt_dev->svlan_p);
 			svlan_encapsulated_proto = skb_put(skb,
 							   sizeof(__be16));
 			*svlan_encapsulated_proto = htons(ETH_P_8021Q);
 		}
 		vlan_tci = skb_put(skb, sizeof(__be16));
 		*vlan_tci = build_tci(pkt_dev->vlan_id,
 				      pkt_dev->vlan_cfi,
 				      pkt_dev->vlan_p);
 		vlan_encapsulated_proto = skb_put(skb, sizeof(__be16));
 		*vlan_encapsulated_proto = htons(ETH_P_IPV6);
 	}

 	skb_reset_mac_header(skb);
 	skb_set_network_header(skb, skb->len);
 	iph = skb_put(skb, sizeof(struct ipv6hdr));

 	skb_set_transport_header(skb, skb->len);
 	udph = skb_put(skb, sizeof(struct udphdr));
 	skb_set_queue_mapping(skb, queue_map);
 	skb->priority = pkt_dev->skb_priority;

 	memcpy(eth, pkt_dev->hh, 12);
 	*(__be16 *) &eth[12] = protocol;

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

 	if (datalen < 0 || datalen < sizeof(struct pktgen_hdr)) {
 		datalen = sizeof(struct pktgen_hdr);
 		net_info_ratelimited("increased datalen to %d\n", datalen);
 	}

 	udplen = datalen + sizeof(struct udphdr);
 	udph->source = htons(pkt_dev->cur_udp_src);
 	udph->dest = htons(pkt_dev->cur_udp_dst);
 	udph->len = htons(udplen);
 	udph->check = 0;

 	*(__be32 *) iph = htonl(0x60000000);	/* Version + flow */

 	if (pkt_dev->traffic_class) {
 		/* Version + traffic class + flow (0) */
 		*(__be32 *)iph |= htonl(0x60000000 | (pkt_dev->traffic_class << 20));
 	}

 	iph->hop_limit = 32;

 	iph->payload_len = htons(udplen);
 	iph->nexthdr = IPPROTO_UDP;

 	iph->daddr = pkt_dev->cur_in6_daddr;
 	iph->saddr = pkt_dev->cur_in6_saddr;

 	skb->protocol = protocol;
 	skb->dev = odev;
 	skb->pkt_type = PACKET_HOST;

 	pktgen_finalize_skb(pkt_dev, skb, datalen);

 	if (!(pkt_dev->flags & F_UDPCSUM)) {
 		skb->ip_summed = CHECKSUM_NONE;
 	} else if (odev->features & (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM)) {
 		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb->csum_start = skb_transport_header(skb) - skb->head;
 		skb->csum_offset = offsetof(struct udphdr, check);
 		udph->check = ~csum_ipv6_magic(&iph->saddr, &iph->daddr, udplen, IPPROTO_UDP, 0);
 	} else {
 		__wsum csum = skb_checksum(skb, skb_transport_offset(skb), udplen, 0);

 		/* add protocol-dependent pseudo-header */
 		udph->check = csum_ipv6_magic(&iph->saddr, &iph->daddr, udplen, IPPROTO_UDP, csum);

 		if (udph->check == 0)
 			udph->check = CSUM_MANGLED_0;
 	}

 	return skb;
 }

 static 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;

 	func_enter();

 	rcu_read_lock();
 	list_for_each_entry_rcu(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->skb = NULL;
 			pkt_dev->started_at = pkt_dev->next_tx = ktime_get();

 			set_pkt_overhead(pkt_dev);

 			strcpy(pkt_dev->result, "Starting");
 			pkt_dev->running = 1;	/* Cranke yeself! */
 			started++;
 		} else
 			strcpy(pkt_dev->result, "Error starting");
 	}
 	rcu_read_unlock();
 	if (started)
 		t->control &= ~(T_STOP);
 }

 static void pktgen_handle_all_threads(struct pktgen_net *pn, u32 flags)
 {
 	struct pktgen_thread *t;

 	mutex_lock(&pktgen_thread_lock);

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

 	mutex_unlock(&pktgen_thread_lock);
 }

 static void pktgen_stop_all_threads(struct pktgen_net *pn)
 {
 	func_enter();

 	pktgen_handle_all_threads(pn, T_STOP);
 }

 static int thread_is_running(const struct pktgen_thread *t)
 {
 	const struct pktgen_dev *pkt_dev;

 	rcu_read_lock();
 	list_for_each_entry_rcu(pkt_dev, &t->if_list, list)
 		if (pkt_dev->running) {
 			rcu_read_unlock();
 			return 1;
 		}
 	rcu_read_unlock();
 	return 0;
 }

 static int pktgen_wait_thread_run(struct pktgen_thread *t)
 {
 	while (thread_is_running(t)) {

 		/* note: 't' will still be around even after the unlock/lock
 		 * cycle because pktgen_thread threads are only cleared at
 		 * net exit
 		 */
 		mutex_unlock(&pktgen_thread_lock);
 		msleep_interruptible(100);
 		mutex_lock(&pktgen_thread_lock);

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

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

 	/* prevent from racing with rmmod */
 	if (!try_module_get(THIS_MODULE))
 		return sig;

 	mutex_lock(&pktgen_thread_lock);

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

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

 	mutex_unlock(&pktgen_thread_lock);
 	module_put(THIS_MODULE);
 	return sig;
 }

 static void pktgen_run_all_threads(struct pktgen_net *pn)
 {
 	func_enter();

 	pktgen_handle_all_threads(pn, T_RUN);

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

 	pktgen_wait_all_threads_run(pn);
 }

 static void pktgen_reset_all_threads(struct pktgen_net *pn)
 {
 	func_enter();

 	pktgen_handle_all_threads(pn, T_REMDEVALL);

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

 	pktgen_wait_all_threads_run(pn);
 }

 static void show_results(struct pktgen_dev *pkt_dev, int nr_frags)
 {
 	__u64 bps, mbps, pps;
 	char *p = pkt_dev->result;
 	ktime_t elapsed = ktime_sub(pkt_dev->stopped_at,
 				    pkt_dev->started_at);
 	ktime_t idle = ns_to_ktime(pkt_dev->idle_acc);

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

 	pps = div64_u64(pkt_dev->sofar * NSEC_PER_SEC,
 			ktime_to_ns(elapsed));

 	if (pkt_dev->n_imix_entries > 0) {
 		int i;
 		struct imix_pkt *entry;

 		bps = 0;
 		for (i = 0; i < pkt_dev->n_imix_entries; i++) {
 			entry = &pkt_dev->imix_entries[i];
 			bps += entry->size * entry->count_so_far;
 		}
 		bps = div64_u64(bps * 8 * NSEC_PER_SEC, ktime_to_ns(elapsed));
 	} else {
 		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) {
 		pr_warn("interface: %s is already stopped\n",
 			pkt_dev->odevname);
 		return -EINVAL;
 	}

 	pkt_dev->running = 0;
 	kfree_skb(pkt_dev->skb);
 	pkt_dev->skb = NULL;
 	pkt_dev->stopped_at = ktime_get();

 	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;

 	rcu_read_lock();
 	list_for_each_entry_rcu(pkt_dev, &t->if_list, list) {
 		if (!pkt_dev->running)
 			continue;
 		if (best == NULL)
 			best = pkt_dev;
 		else if (ktime_compare(pkt_dev->next_tx, best->next_tx) < 0)
 			best = pkt_dev;
 	}
 	rcu_read_unlock();

 	return best;
 }

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

 	func_enter();

 	rcu_read_lock();

 	list_for_each_entry_rcu(pkt_dev, &t->if_list, list) {
 		pktgen_stop_device(pkt_dev);
 	}

 	rcu_read_unlock();
 }

 /*
  * 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;

 	func_enter();

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

 		if (!cur->removal_mark)
 			continue;

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

 		pktgen_remove_device(t, cur);

 		break;
 	}
 }

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

 	func_enter();

 	/* Remove all devices, free mem */

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

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

 		pktgen_remove_device(t, cur);
 	}
 }

 static void pktgen_rem_thread(struct pktgen_thread *t)
 {
 	/* Remove from the thread list */
 	remove_proc_entry(t->tsk->comm, t->net->proc_dir);
 }

 static void pktgen_resched(struct pktgen_dev *pkt_dev)
 {
 	ktime_t idle_start = ktime_get();
 	schedule();
 	pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_get(), idle_start));
 }

 static void pktgen_wait_for_skb(struct pktgen_dev *pkt_dev)
 {
 	ktime_t idle_start = ktime_get();

 	while (refcount_read(&(pkt_dev->skb->users)) != 1) {
 		if (signal_pending(current))
 			break;

 		if (need_resched())
 			pktgen_resched(pkt_dev);
 		else
 			cpu_relax();
 	}
 	pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_get(), idle_start));
 }

 static void pktgen_xmit(struct pktgen_dev *pkt_dev)
 {
 	bool skb_shared = !!(READ_ONCE(pkt_dev->flags) & F_SHARED);
 	struct net_device *odev = pkt_dev->odev;
 	struct netdev_queue *txq;
 	unsigned int burst = 1;
 	struct sk_buff *skb;
 	int clone_skb = 0;
 	int ret;

 	/* If 'skb_shared' is false, the read of possible
 	 * new values (if any) for 'burst' and 'clone_skb' will be skipped to
 	 * prevent some concurrent changes from slipping in. And the stabilized
 	 * config will be read in during the next run of pktgen_xmit.
 	 */
 	if (skb_shared) {
 		burst = READ_ONCE(pkt_dev->burst);
 		clone_skb = READ_ONCE(pkt_dev->clone_skb);
 	}

 	/* If device is offline, then don't send */
 	if (unlikely(!netif_running(odev) || !netif_carrier_ok(odev))) {
 		pktgen_stop_device(pkt_dev);
 		return;
 	}

 	/* This is max DELAY, this has special meaning of
 	 * "never transmit"
 	 */
 	if (unlikely(pkt_dev->delay == ULLONG_MAX)) {
 		pkt_dev->next_tx = ktime_add_ns(ktime_get(), ULONG_MAX);
 		return;
 	}

 	/* If no skb or clone count exhausted then get new one */
 	if (!pkt_dev->skb || (pkt_dev->last_ok &&
 			      ++pkt_dev->clone_count >= clone_skb)) {
 		/* build a new pkt */
 		kfree_skb(pkt_dev->skb);

 		pkt_dev->skb = fill_packet(odev, pkt_dev);
 		if (pkt_dev->skb == NULL) {
 			pr_err("ERROR: couldn't allocate skb in fill_packet\n");
 			schedule();
 			pkt_dev->clone_count--;	/* back out increment, OOM */
 			return;
 		}
 		pkt_dev->last_pkt_size = pkt_dev->skb->len;
 		pkt_dev->clone_count = 0;	/* reset counter */
 	}

 	if (pkt_dev->delay && pkt_dev->last_ok)
 		spin(pkt_dev, pkt_dev->next_tx);

 	if (pkt_dev->xmit_mode == M_NETIF_RECEIVE) {
 		skb = pkt_dev->skb;
 		skb->protocol = eth_type_trans(skb, skb->dev);
 		if (skb_shared)
 			refcount_add(burst, &skb->users);
 		local_bh_disable();
 		do {
 			ret = netif_receive_skb(skb);
 			if (ret == NET_RX_DROP)
 				pkt_dev->errors++;
 			pkt_dev->sofar++;
 			pkt_dev->seq_num++;
 			if (unlikely(!skb_shared)) {
 				pkt_dev->skb = NULL;
 				break;
 			}
 			if (refcount_read(&skb->users) != burst) {
 				/* skb was queued by rps/rfs or taps,
 				 * so cannot reuse this skb
 				 */
 				WARN_ON(refcount_sub_and_test(burst - 1, &skb->users));
 				/* get out of the loop and wait
 				 * until skb is consumed
 				 */
 				break;
 			}
 			/* skb was 'freed' by stack, so clean few
 			 * bits and reuse it
 			 */
 			skb_reset_redirect(skb);
 		} while (--burst > 0);
 		goto out; /* Skips xmit_mode M_START_XMIT */
 	} else if (pkt_dev->xmit_mode == M_QUEUE_XMIT) {
 		local_bh_disable();
 		if (skb_shared)
 			refcount_inc(&pkt_dev->skb->users);

 		ret = dev_queue_xmit(pkt_dev->skb);

 		if (!skb_shared && dev_xmit_complete(ret))
 			pkt_dev->skb = NULL;

 		switch (ret) {
 		case NET_XMIT_SUCCESS:
 			pkt_dev->sofar++;
 			pkt_dev->seq_num++;
 			pkt_dev->tx_bytes += pkt_dev->last_pkt_size;
 			break;
 		case NET_XMIT_DROP:
 		case NET_XMIT_CN:
 		/* These are all valid return codes for a qdisc but
 		 * indicate packets are being dropped or will likely
 		 * be dropped soon.
 		 */
 		case NETDEV_TX_BUSY:
 		/* qdisc may call dev_hard_start_xmit directly in cases
 		 * where no queues exist e.g. loopback device, virtual
 		 * devices, etc. In this case we need to handle
 		 * NETDEV_TX_ codes.
 		 */
 		default:
 			pkt_dev->errors++;
 			net_info_ratelimited("%s xmit error: %d\n",
 					     pkt_dev->odevname, ret);
 			break;
 		}
 		goto out;
 	}

 	txq = skb_get_tx_queue(odev, pkt_dev->skb);

 	local_bh_disable();

 	HARD_TX_LOCK(odev, txq, smp_processor_id());

 	if (unlikely(netif_xmit_frozen_or_drv_stopped(txq))) {
 		pkt_dev->last_ok = 0;
 		goto unlock;
 	}
 	if (skb_shared)
 		refcount_add(burst, &pkt_dev->skb->users);

 xmit_more:
 	ret = netdev_start_xmit(pkt_dev->skb, odev, txq, --burst > 0);

 	if (!skb_shared && dev_xmit_complete(ret))
 		pkt_dev->skb = NULL;

 	switch (ret) {
 	case NETDEV_TX_OK:
 		pkt_dev->last_ok = 1;
 		pkt_dev->sofar++;
 		pkt_dev->seq_num++;
 		pkt_dev->tx_bytes += pkt_dev->last_pkt_size;
 		if (burst > 0 && !netif_xmit_frozen_or_drv_stopped(txq))
 			goto xmit_more;
 		break;
 	case NET_XMIT_DROP:
 	case NET_XMIT_CN:
 		/* skb has been consumed */
 		pkt_dev->errors++;
 		break;
 	default: /* Drivers are not supposed to return other values! */
 		net_info_ratelimited("%s xmit error: %d\n",
 				     pkt_dev->odevname, ret);
 		pkt_dev->errors++;
 		fallthrough;
 	case NETDEV_TX_BUSY:
 		/* Retry it next time */
 		if (skb_shared)
 			refcount_dec(&pkt_dev->skb->users);
 		pkt_dev->last_ok = 0;
 	}
 	if (unlikely(burst))
 		WARN_ON(refcount_sub_and_test(burst, &pkt_dev->skb->users));
 unlock:
 	HARD_TX_UNLOCK(odev, txq);

 out:
 	local_bh_enable();

 	/* If pkt_dev->count is zero, then run forever */
 	if ((pkt_dev->count != 0) && (pkt_dev->sofar >= pkt_dev->count)) {
 		if (pkt_dev->skb)
 			pktgen_wait_for_skb(pkt_dev);

 		/* Done with this */
 		pktgen_stop_device(pkt_dev);
 	}
 }

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

 static int pktgen_thread_worker(void *arg)
 {
 	struct pktgen_thread *t = arg;
 	struct pktgen_dev *pkt_dev = NULL;
 	int cpu = t->cpu;

 	WARN_ON(smp_processor_id() != cpu);

 	init_waitqueue_head(&t->queue);
 	complete(&t->start_done);

 	pr_debug("starting pktgen/%d:  pid=%d\n", cpu, task_pid_nr(current));

 	set_freezable();

 	while (!kthread_should_stop()) {
 		pkt_dev = next_to_run(t);

 		if (unlikely(!pkt_dev && t->control == 0)) {
 			if (t->net->pktgen_exiting)
 				break;
 			wait_event_freezable_timeout(t->queue,
 						     t->control != 0, HZ / 10);
 			continue;
 		}

 		if (likely(pkt_dev)) {
 			pktgen_xmit(pkt_dev);

 			if (need_resched())
 				pktgen_resched(pkt_dev);
 			else
 				cpu_relax();
 		}

 		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);
 		}

 		try_to_freeze();
 	}

 	pr_debug("%s stopping all device\n", t->tsk->comm);
 	pktgen_stop(t);

 	pr_debug("%s removing all device\n", t->tsk->comm);
 	pktgen_rem_all_ifs(t);

 	pr_debug("%s removing thread\n", t->tsk->comm);
 	pktgen_rem_thread(t);

 	return 0;
 }

 static struct pktgen_dev *pktgen_find_dev(struct pktgen_thread *t,
 					  const char *ifname, bool exact)
 {
 	struct pktgen_dev *p, *pkt_dev = NULL;
 	size_t len = strlen(ifname);

 	rcu_read_lock();
 	list_for_each_entry_rcu(p, &t->if_list, list)
 		if (strncmp(p->odevname, ifname, len) == 0) {
 			if (p->odevname[len]) {
 				if (exact || p->odevname[len] != '@')
 					continue;
 			}
 			pkt_dev = p;
 			break;
 		}

 	rcu_read_unlock();
 	pr_debug("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;

 	/* This function cannot be called concurrently, as its called
 	 * under pktgen_thread_lock mutex, but it can run from
 	 * userspace on another CPU than the kthread.  The if_lock()
 	 * is used here to sync with concurrent instances of
 	 * _rem_dev_from_if_list() invoked via kthread, which is also
 	 * updating the if_list */
 	if_lock(t);

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

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

 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;
 	int err;
 	int node = cpu_to_node(t->cpu);

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

 	pkt_dev = __pktgen_NN_threads(t->net, ifname, FIND);
 	if (pkt_dev) {
 		pr_err("ERROR: interface already used\n");
 		return -EBUSY;
 	}

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

 	strcpy(pkt_dev->odevname, ifname);
 	pkt_dev->flows = vzalloc_node(array_size(MAX_CFLOWS,
 						 sizeof(struct flow_state)),
 				      node);
 	if (pkt_dev->flows == NULL) {
 		kfree(pkt_dev);
 		return -ENOMEM;
 	}

 	pkt_dev->removal_mark = 0;
 	pkt_dev->nfrags = 0;
 	pkt_dev->delay = pg_delay_d;
 	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;
 	pkt_dev->vlan_p = 0;
 	pkt_dev->vlan_cfi = 0;
 	pkt_dev->vlan_id = 0xffff;
 	pkt_dev->svlan_p = 0;
 	pkt_dev->svlan_cfi = 0;
 	pkt_dev->svlan_id = 0xffff;
 	pkt_dev->burst = 1;
 	pkt_dev->node = NUMA_NO_NODE;
 	pkt_dev->flags = F_SHARED;	/* SKB shared by default */

 	err = pktgen_setup_dev(t->net, pkt_dev, ifname);
 	if (err)
 		goto out1;
 	if (pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)
 		pkt_dev->clone_skb = pg_clone_skb_d;

 	pkt_dev->entry = proc_create_data(ifname, 0600, t->net->proc_dir,
 					  &pktgen_if_proc_ops, pkt_dev);
 	if (!pkt_dev->entry) {
 		pr_err("cannot create %s/%s procfs entry\n",
 		       PG_PROC_DIR, ifname);
 		err = -EINVAL;
 		goto out2;
 	}
 #ifdef CONFIG_XFRM
 	pkt_dev->ipsmode = XFRM_MODE_TRANSPORT;
 	pkt_dev->ipsproto = IPPROTO_ESP;

 	/* xfrm tunnel mode needs additional dst to extract outter
 	 * ip header protocol/ttl/id field, here creat a phony one.
 	 * instead of looking for a valid rt, which definitely hurting
 	 * performance under such circumstance.
 	 */
 	pkt_dev->dstops.family = AF_INET;
 	pkt_dev->xdst.u.dst.dev = pkt_dev->odev;
 	dst_init_metrics(&pkt_dev->xdst.u.dst, pktgen_dst_metrics, false);
 	pkt_dev->xdst.child = &pkt_dev->xdst.u.dst;
 	pkt_dev->xdst.u.dst.ops = &pkt_dev->dstops;
 #endif

 	return add_dev_to_thread(t, pkt_dev);
 out2:
 	netdev_put(pkt_dev->odev, &pkt_dev->dev_tracker);
 out1:
 #ifdef CONFIG_XFRM
 	free_SAs(pkt_dev);
 #endif
 	vfree(pkt_dev->flows);
 	kfree(pkt_dev);
 	return err;
 }

 static int __net_init pktgen_create_thread(int cpu, struct pktgen_net *pn)
 {
 	struct pktgen_thread *t;
 	struct proc_dir_entry *pe;
 	struct task_struct *p;

 	t = kzalloc_node(sizeof(struct pktgen_thread), GFP_KERNEL,
 			 cpu_to_node(cpu));
 	if (!t) {
 		pr_err("ERROR: out of memory, can't create new thread\n");
 		return -ENOMEM;
 	}

 	mutex_init(&t->if_lock);
 	t->cpu = cpu;

 	INIT_LIST_HEAD(&t->if_list);

 	list_add_tail(&t->th_list, &pn->pktgen_threads);
 	init_completion(&t->start_done);

 	p = kthread_create_on_node(pktgen_thread_worker,
 				   t,
 				   cpu_to_node(cpu),
 				   "kpktgend_%d", cpu);
 	if (IS_ERR(p)) {
 		pr_err("kthread_create_on_node() failed for cpu %d\n", t->cpu);
 		list_del(&t->th_list);
 		kfree(t);
 		return PTR_ERR(p);
 	}
 	kthread_bind(p, cpu);
 	t->tsk = p;

 	pe = proc_create_data(t->tsk->comm, 0600, pn->proc_dir,
 			      &pktgen_thread_proc_ops, t);
 	if (!pe) {
 		pr_err("cannot create %s/%s procfs entry\n",
 		       PG_PROC_DIR, t->tsk->comm);
 		kthread_stop(p);
 		list_del(&t->th_list);
 		kfree(t);
 		return -EINVAL;
 	}

 	t->net = pn;
 	get_task_struct(p);
 	wake_up_process(p);
 	wait_for_completion(&t->start_done);

 	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;

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

 static int pktgen_remove_device(struct pktgen_thread *t,
 				struct pktgen_dev *pkt_dev)
 {
 	pr_debug("remove_device pkt_dev=%p\n", pkt_dev);

 	if (pkt_dev->running) {
 		pr_warn("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) {
 		netdev_put(pkt_dev->odev, &pkt_dev->dev_tracker);
 		pkt_dev->odev = NULL;
 	}

 	/* Remove proc before if_list entry, because add_device uses
 	 * list to determine if interface already exist, avoid race
 	 * with proc_create_data() */
 	proc_remove(pkt_dev->entry);

 	/* And update the thread if_list */
 	_rem_dev_from_if_list(t, pkt_dev);

 #ifdef CONFIG_XFRM
 	free_SAs(pkt_dev);
 #endif
 	vfree(pkt_dev->flows);
 	if (pkt_dev->page)
 		put_page(pkt_dev->page);
 	kfree_rcu(pkt_dev, rcu);
 	return 0;
 }

 static int __net_init pg_net_init(struct net *net)
 {
 	struct pktgen_net *pn = net_generic(net, pg_net_id);
 	struct proc_dir_entry *pe;
 	int cpu, ret = 0;

 	pn->net = net;
 	INIT_LIST_HEAD(&pn->pktgen_threads);
 	pn->pktgen_exiting = false;
 	pn->proc_dir = proc_mkdir(PG_PROC_DIR, pn->net->proc_net);
 	if (!pn->proc_dir) {
 		pr_warn("cannot create /proc/net/%s\n", PG_PROC_DIR);
 		return -ENODEV;
 	}
 	pe = proc_create(PGCTRL, 0600, pn->proc_dir, &pktgen_proc_ops);
 	if (pe == NULL) {
 		pr_err("cannot create %s procfs entry\n", PGCTRL);
 		ret = -EINVAL;
 		goto remove;
 	}

 	for_each_online_cpu(cpu) {
 		int err;

 		err = pktgen_create_thread(cpu, pn);
 		if (err)
 			pr_warn("Cannot create thread for cpu %d (%d)\n",
 				   cpu, err);
 	}

 	if (list_empty(&pn->pktgen_threads)) {
 		pr_err("Initialization failed for all threads\n");
 		ret = -ENODEV;
 		goto remove_entry;
 	}

 	return 0;

 remove_entry:
 	remove_proc_entry(PGCTRL, pn->proc_dir);
 remove:
 	remove_proc_entry(PG_PROC_DIR, pn->net->proc_net);
 	return ret;
 }

 static void __net_exit pg_net_exit(struct net *net)
 {
 	struct pktgen_net *pn = net_generic(net, pg_net_id);
 	struct pktgen_thread *t;
 	struct list_head *q, *n;
 	LIST_HEAD(list);

 	/* Stop all interfaces & threads */
 	pn->pktgen_exiting = true;

 	mutex_lock(&pktgen_thread_lock);
 	list_splice_init(&pn->pktgen_threads, &list);
 	mutex_unlock(&pktgen_thread_lock);

 	list_for_each_safe(q, n, &list) {
 		t = list_entry(q, struct pktgen_thread, th_list);
 		list_del(&t->th_list);
 		kthread_stop_put(t->tsk);
 		kfree(t);
 	}

 	remove_proc_entry(PGCTRL, pn->proc_dir);
 	remove_proc_entry(PG_PROC_DIR, pn->net->proc_net);
 }

 static struct pernet_operations pg_net_ops = {
 	.init = pg_net_init,
 	.exit = pg_net_exit,
 	.id   = &pg_net_id,
 	.size = sizeof(struct pktgen_net),
 };

 static int __init pg_init(void)
 {
 	int ret = 0;

 	pr_info("%s", version);
 	ret = register_pernet_subsys(&pg_net_ops);
 	if (ret)
 		return ret;
 	ret = register_netdevice_notifier(&pktgen_notifier_block);
 	if (ret)
 		unregister_pernet_subsys(&pg_net_ops);

 	return ret;
 }

 static void __exit pg_cleanup(void)
 {
 	unregister_netdevice_notifier(&pktgen_notifier_block);
 	unregister_pernet_subsys(&pg_net_ops);
 	/* Don't need rcu_barrier() due to use of kfree_rcu() */
 }

 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_VERSION(VERSION);
 module_param(pg_count_d, int, 0);
 MODULE_PARM_DESC(pg_count_d, "Default number of packets to inject");
 module_param(pg_delay_d, int, 0);
 MODULE_PARM_DESC(pg_delay_d, "Default delay between packets (nanoseconds)");
 module_param(pg_clone_skb_d, int, 0);
 MODULE_PARM_DESC(pg_clone_skb_d, "Default number of copies of the same packet");
 module_param(debug, int, 0);
 MODULE_PARM_DESC(debug, "Enable debugging of pktgen module");