// 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.txt for how to use this.
 *
 * The new operation:
 * For each CPU one thread/process is created at start. This process checks
 * for running devices in the if_list and sends packets until count is 0 it
 * also the thread checks the thread->control which is used for inter-process
 * communication. controlling process "posts" operations to the threads this
 * way.
 * The if_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)

#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*/                  \

#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 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) */

        /* 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.)
                                  */
        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_ifs(struct pktgen_net *pn);

static void pktgen_stop(struct pktgen_thread *t);
static void pktgen_clear_counters(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_ifs(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 file_operations pktgen_fops = {
        .open    = pgctrl_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
        .write   = pgctrl_write,
        .release = single_release,
};

static int pktgen_if_show(struct seq_file *seq, void *v)
{
        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);

        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 == F_FLOW_SEQ)
                        if (!pkt_dev->cflows)
                                continue;

                if (pkt_dev->flags & (1 << i))
                        seq_printf(seq, "%s  ", pkt_flag_names[i]);
                else if (i == F_FLOW_SEQ)
                        seq_puts(seq, "FLOW_RND  ");

#ifdef CONFIG_XFRM
                if (i == F_IPSEC && pkt_dev->spi)
                        seq_printf(seq, "spi:%u", pkt_dev->spi);
#endif
        }

        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);

        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;
}

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

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

                i += len;
                if (value < 14 + 20 + 8)
                        value = 14 + 20 + 8;
                if (value != pkt_dev->max_pkt_size) {
                        pkt_dev->max_pkt_size = value;
                        pkt_dev->cur_pkt_size = value;
                }
                sprintf(pg_result, "OK: max_pkt_size=%u",
                        pkt_dev->max_pkt_size);
                return count;
        }

        /* Shortcut for min = max */

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

                i += len;
                if (value < 14 + 20 + 8)
                        value = 14 + 20 + 8;
                if (value != pkt_dev->min_pkt_size) {
                        pkt_dev->min_pkt_size = value;
                        pkt_dev->max_pkt_size = value;
                        pkt_dev->cur_pkt_size = value;
                }
                sprintf(pg_result, "OK: pkt_size=%u", pkt_dev->min_pkt_size);
                return count;
        }

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

                i += len;
                debug = value;
                sprintf(pg_result, "OK: debug=%u", debug);
                return count;
        }

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

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

                i += len;
                if (value == 0x7FFFFFFF)
                        pkt_dev->delay = 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;
                if ((value > 0) &&
                    ((pkt_dev->xmit_mode == M_NETIF_RECEIVE) ||
                     !(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
                        return -ENOTSUPP;
                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;
                pkt_dev->burst = value < 1 ? 1 : value;
                sprintf(pg_result, "OK: burst=%d", 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;

                        /* override clone_skb if user passed default value
                         * at module loading time
                         */
                        pkt_dev->clone_skb = 0;
                } 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")) {
                __u32 flag;
                char f[32];
                bool disable = false;

                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)
                                pkt_dev->flags &= ~flag;
                        else
                                pkt_dev->flags |= flag;
                } else {
                        sprintf(pg_result,
                                "Flag -:%s:- unknown\nAvailable flags, (prepend ! to un-set flag):\n%s",
                                f,
                                "IPSRC_RND, IPDST_RND, UDPSRC_RND, UDPDST_RND, "
                                "MACSRC_RND, MACDST_RND, TXSIZE_RND, IPV6, "
                                "MPLS_RND, VID_RND, SVID_RND, FLOW_SEQ, "
                                "QUEUE_MAP_RND, QUEUE_MAP_CPU, UDPCSUM, "
                                "NO_TIMESTAMP, "
#ifdef CONFIG_XFRM
                                "IPSEC, "
#endif
                                "NODE_ALLOC\n");
                        return count;
                }
                sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
                return count;
        }
        if (!strcmp(name, "dst_min") || !strcmp(name, "dst")) {
                len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_min) - 1);
                if (len < 0)
                        return len;

                if (copy_from_user(buf, &user_buffer[i], len))
                        return -EFAULT;
                buf[len] = 0;
                if (strcmp(buf, pkt_dev->dst_min) != 0) {
                        memset(pkt_dev->dst_min, 0, sizeof(pkt_dev->dst_min));
                        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 file_operations pktgen_if_fops = {
        .open    = pktgen_if_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
        .write   = pktgen_if_write,
        .release = single_release,
};

static int pktgen_thread_show(struct seq_file *seq, void *v)
{
        struct pktgen_thread *t = seq->private;
        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 file_operations pktgen_thread_fops = {
        .open    = pktgen_thread_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
        .write   = pktgen_thread_write,
        .release = single_release,
};

/* Think find or remove for NN */
static struct pktgen_dev *__pktgen_NN_threads(const 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_fops,
                                                          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) {
                dev_put(pkt_dev->odev);
                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) {
                pr_err("not an ethernet 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;
                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 = prandom_u32() % 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 = prandom_u32() %
                                (pkt_dev->queue_map_max -
                                 pkt_dev->queue_map_min + 1)
                                + pkt_dev->queue_map_min;
                } 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 = prandom_u32() % 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 = prandom_u32() % 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)prandom_u32() &
                                                      htonl(0x000fffff));
        }

        if ((pkt_dev->flags & F_VID_RND) && (pkt_dev->vlan_id != 0xffff)) {
                pkt_dev->vlan_id = prandom_u32() & (4096 - 1);
        }

        if ((pkt_dev->flags & F_SVID_RND) && (pkt_dev->svlan_id != 0xffff)) {
                pkt_dev->svlan_id = prandom_u32() & (4096 - 1);
        }

        if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
                if (pkt_dev->flags & F_UDPSRC_RND)
                        pkt_dev->cur_udp_src = prandom_u32() %
                                (pkt_dev->udp_src_max - pkt_dev->udp_src_min)
                                + pkt_dev->udp_src_min;

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

        if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
                if (pkt_dev->flags & F_UDPDST_RND) {
                        pkt_dev->cur_udp_dst = prandom_u32() %
                                (pkt_dev->udp_dst_max - pkt_dev->udp_dst_min)
                                + pkt_dev->udp_dst_min;
                } else {
                        pkt_dev->cur_udp_dst++;
                        if (pkt_dev->cur_udp_dst >= pkt_dev->udp_dst_max)
                                pkt_dev->cur_udp_dst = pkt_dev->udp_dst_min;
                }
        }

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

                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 = prandom_u32() % (imx - imn) + imn;
                        else {
                                t = ntohl(pkt_dev->cur_saddr);
                                t++;
                                if (t > imx)
                                        t = imn;

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

                if (pkt_dev->cflows && 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 = prandom_u32() %
                                                        (imx - imn) + imn;
                                                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)prandom_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 = prandom_u32() %
                                (pkt_dev->max_pkt_size - pkt_dev->min_pkt_size)
                                + pkt_dev->min_pkt_size;
                } else {
                        t = pkt_dev->cur_pkt_size + 1;
                        if (t > pkt_dev->max_pkt_size)
                                t = pkt_dev->min_pkt_size;
                }
                pkt_dev->cur_pkt_size = t;
        }

        set_cur_queue_map(pkt_dev);

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


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