// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
 */
static const char *__doc__ =
        " XDP redirect with a CPU-map type \"BPF_MAP_TYPE_CPUMAP\"";

#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>
#include <sys/resource.h>
#include <sys/sysinfo.h>
#include <getopt.h>
#include <net/if.h>
#include <time.h>
#include <linux/limits.h>

#include <arpa/inet.h>
#include <linux/if_link.h>

/* How many xdp_progs are defined in _kern.c */
#define MAX_PROG 6

#include <bpf/bpf.h>
#include <bpf/libbpf.h>

#include "bpf_util.h"

static int ifindex = -1;
static char ifname_buf[IF_NAMESIZE];
static char *ifname;
static __u32 prog_id;

static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static int n_cpus;

enum map_type {
        CPU_MAP,
        RX_CNT,
        REDIRECT_ERR_CNT,
        CPUMAP_ENQUEUE_CNT,
        CPUMAP_KTHREAD_CNT,
        CPUS_AVAILABLE,
        CPUS_COUNT,
        CPUS_ITERATOR,
        EXCEPTION_CNT,
};

static const char *const map_type_strings[] = {
        [CPU_MAP] = "cpu_map",
        [RX_CNT] = "rx_cnt",
        [REDIRECT_ERR_CNT] = "redirect_err_cnt",
        [CPUMAP_ENQUEUE_CNT] = "cpumap_enqueue_cnt",
        [CPUMAP_KTHREAD_CNT] = "cpumap_kthread_cnt",
        [CPUS_AVAILABLE] = "cpus_available",
        [CPUS_COUNT] = "cpus_count",
        [CPUS_ITERATOR] = "cpus_iterator",
        [EXCEPTION_CNT] = "exception_cnt",
};

#define NUM_TP 5
#define NUM_MAP 9
struct bpf_link *tp_links[NUM_TP] = {};
static int map_fds[NUM_MAP];
static int tp_cnt = 0;

/* Exit return codes */
#define EXIT_OK         0
#define EXIT_FAIL               1
#define EXIT_FAIL_OPTION        2
#define EXIT_FAIL_XDP           3
#define EXIT_FAIL_BPF           4
#define EXIT_FAIL_MEM           5

static const struct option long_options[] = {
        {"help",        no_argument,            NULL, 'h' },
        {"dev",         required_argument,      NULL, 'd' },
        {"skb-mode",    no_argument,            NULL, 'S' },
        {"sec",         required_argument,      NULL, 's' },
        {"progname",    required_argument,      NULL, 'p' },
        {"qsize",       required_argument,      NULL, 'q' },
        {"cpu",         required_argument,      NULL, 'c' },
        {"stress-mode", no_argument,            NULL, 'x' },
        {"no-separators", no_argument,          NULL, 'z' },
        {"force",       no_argument,            NULL, 'F' },
        {"mprog-disable", no_argument,          NULL, 'n' },
        {"mprog-name",  required_argument,      NULL, 'e' },
        {"mprog-filename", required_argument,   NULL, 'f' },
        {"redirect-device", required_argument,  NULL, 'r' },
        {"redirect-map", required_argument,     NULL, 'm' },
        {0, 0, NULL,  0 }
};

static void int_exit(int sig)
{
        __u32 curr_prog_id = 0;

        if (ifindex > -1) {
                if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
                        printf("bpf_get_link_xdp_id failed\n");
                        exit(EXIT_FAIL);
                }
                if (prog_id == curr_prog_id) {
                        fprintf(stderr,
                                "Interrupted: Removing XDP program on ifindex:%d device:%s\n",
                                ifindex, ifname);
                        bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
                } else if (!curr_prog_id) {
                        printf("couldn't find a prog id on a given iface\n");
                } else {
                        printf("program on interface changed, not removing\n");
                }
        }
        /* Detach tracepoints */
        while (tp_cnt)
                bpf_link__destroy(tp_links[--tp_cnt]);

        exit(EXIT_OK);
}

static void print_avail_progs(struct bpf_object *obj)
{
        struct bpf_program *pos;

        bpf_object__for_each_program(pos, obj) {
                if (bpf_program__is_xdp(pos))
                        printf(" %s\n", bpf_program__section_name(pos));
        }
}

static void usage(char *argv[], struct bpf_object *obj)
{
        int i;

        printf("\nDOCUMENTATION:\n%s\n", __doc__);
        printf("\n");
        printf(" Usage: %s (options-see-below)\n", argv[0]);
        printf(" Listing options:\n");
        for (i = 0; long_options[i].name != 0; i++) {
                printf(" --%-12s", long_options[i].name);
                if (long_options[i].flag != NULL)
                        printf(" flag (internal value:%d)",
                                *long_options[i].flag);
                else
                        printf(" short-option: -%c",
                                long_options[i].val);
                printf("\n");
        }
        printf("\n Programs to be used for --progname:\n");
        print_avail_progs(obj);
        printf("\n");
}

/* gettime returns the current time of day in nanoseconds.
 * Cost: clock_gettime (ns) => 26ns (CLOCK_MONOTONIC)
 *       clock_gettime (ns) =>  9ns (CLOCK_MONOTONIC_COARSE)
 */
#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
static __u64 gettime(void)
{
        struct timespec t;
        int res;

        res = clock_gettime(CLOCK_MONOTONIC, &t);
        if (res < 0) {
                fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
                exit(EXIT_FAIL);
        }
        return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
}

/* Common stats data record shared with _kern.c */
struct datarec {
        __u64 processed;
        __u64 dropped;
        __u64 issue;
        __u64 xdp_pass;
        __u64 xdp_drop;
        __u64 xdp_redirect;
};
struct record {
        __u64 timestamp;
        struct datarec total;
        struct datarec *cpu;
};
struct stats_record {
        struct record rx_cnt;
        struct record redir_err;
        struct record kthread;
        struct record exception;
        struct record enq[];
};

static bool map_collect_percpu(int fd, __u32 key, struct record *rec)
{
        /* For percpu maps, userspace gets a value per possible CPU */
        unsigned int nr_cpus = bpf_num_possible_cpus();
        struct datarec values[nr_cpus];
        __u64 sum_xdp_redirect = 0;
        __u64 sum_xdp_pass = 0;
        __u64 sum_xdp_drop = 0;
        __u64 sum_processed = 0;
        __u64 sum_dropped = 0;
        __u64 sum_issue = 0;
        int i;

        if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
                fprintf(stderr,
                        "ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
                return false;
        }
        /* Get time as close as possible to reading map contents */
        rec->timestamp = gettime();

        /* Record and sum values from each CPU */
        for (i = 0; i < nr_cpus; i++) {
                rec->cpu[i].processed = values[i].processed;
                sum_processed        += values[i].processed;
                rec->cpu[i].dropped = values[i].dropped;
                sum_dropped        += values[i].dropped;
                rec->cpu[i].issue = values[i].issue;
                sum_issue        += values[i].issue;
                rec->cpu[i].xdp_pass = values[i].xdp_pass;
                sum_xdp_pass += values[i].xdp_pass;
                rec->cpu[i].xdp_drop = values[i].xdp_drop;
                sum_xdp_drop += values[i].xdp_drop;
                rec->cpu[i].xdp_redirect = values[i].xdp_redirect;
                sum_xdp_redirect += values[i].xdp_redirect;
        }
        rec->total.processed = sum_processed;
        rec->total.dropped   = sum_dropped;
        rec->total.issue     = sum_issue;
        rec->total.xdp_pass  = sum_xdp_pass;
        rec->total.xdp_drop  = sum_xdp_drop;
        rec->total.xdp_redirect = sum_xdp_redirect;
        return true;
}

static struct datarec *alloc_record_per_cpu(void)
{
        unsigned int nr_cpus = bpf_num_possible_cpus();
        struct datarec *array;

        array = calloc(nr_cpus, sizeof(struct datarec));
        if (!array) {
                fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
                exit(EXIT_FAIL_MEM);
        }
        return array;
}

static struct stats_record *alloc_stats_record(void)
{
        struct stats_record *rec;
        int i, size;

        size = sizeof(*rec) + n_cpus * sizeof(struct record);
        rec = malloc(size);
        if (!rec) {
                fprintf(stderr, "Mem alloc error\n");
                exit(EXIT_FAIL_MEM);
        }
        memset(rec, 0, size);
        rec->rx_cnt.cpu    = alloc_record_per_cpu();
        rec->redir_err.cpu = alloc_record_per_cpu();
        rec->kthread.cpu   = alloc_record_per_cpu();
        rec->exception.cpu = alloc_record_per_cpu();
        for (i = 0; i < n_cpus; i++)
                rec->enq[i].cpu = alloc_record_per_cpu();

        return rec;
}

static void free_stats_record(struct stats_record *r)
{
        int i;

        for (i = 0; i < n_cpus; i++)
                free(r->enq[i].cpu);
        free(r->exception.cpu);
        free(r->kthread.cpu);
        free(r->redir_err.cpu);
        free(r->rx_cnt.cpu);
        free(r);
}

static double calc_period(struct record *r, struct record *p)
{
        double period_ = 0;
        __u64 period = 0;

        period = r->timestamp - p->timestamp;
        if (period > 0)
                period_ = ((double) period / NANOSEC_PER_SEC);

        return period_;
}

static __u64 calc_pps(struct datarec *r, struct datarec *p, double period_)
{
        __u64 packets = 0;
        __u64 pps = 0;

        if (period_ > 0) {
                packets = r->processed - p->processed;
                pps = packets / period_;
        }
        return pps;
}

static __u64 calc_drop_pps(struct datarec *r, struct datarec *p, double period_)
{
        __u64 packets = 0;
        __u64 pps = 0;

        if (period_ > 0) {
                packets = r->dropped - p->dropped;
                pps = packets / period_;
        }
        return pps;
}

static __u64 calc_errs_pps(struct datarec *r,
                            struct datarec *p, double period_)
{
        __u64 packets = 0;
        __u64 pps = 0;

        if (period_ > 0) {
                packets = r->issue - p->issue;
                pps = packets / period_;
        }
        return pps;
}

static void calc_xdp_pps(struct datarec *r, struct datarec *p,
                         double *xdp_pass, double *xdp_drop,
                         double *xdp_redirect, double period_)
{
        *xdp_pass = 0, *xdp_drop = 0, *xdp_redirect = 0;
        if (period_ > 0) {
                *xdp_redirect = (r->xdp_redirect - p->xdp_redirect) / period_;
                *xdp_pass = (r->xdp_pass - p->xdp_pass) / period_;
                *xdp_drop = (r->xdp_drop - p->xdp_drop) / period_;
        }
}

static void stats_print(struct stats_record *stats_rec,
                        struct stats_record *stats_prev,
                        char *prog_name, char *mprog_name, int mprog_fd)
{
        unsigned int nr_cpus = bpf_num_possible_cpus();
        double pps = 0, drop = 0, err = 0;
        bool mprog_enabled = false;
        struct record *rec, *prev;
        int to_cpu;
        double t;
        int i;

        if (mprog_fd > 0)
                mprog_enabled = true;

        /* Header */
        printf("Running XDP/eBPF prog_name:%s\n", prog_name);
        printf("%-15s %-7s %-14s %-11s %-9s\n",
               "XDP-cpumap", "CPU:to", "pps", "drop-pps", "extra-info");

        /* XDP rx_cnt */
        {
                char *fmt_rx = "%-15s %-7d %'-14.0f %'-11.0f %'-10.0f %s\n";
                char *fm2_rx = "%-15s %-7s %'-14.0f %'-11.0f\n";
                char *errstr = "";

                rec  = &stats_rec->rx_cnt;
                prev = &stats_prev->rx_cnt;
                t = calc_period(rec, prev);
                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];

                        pps = calc_pps(r, p, t);
                        drop = calc_drop_pps(r, p, t);
                        err  = calc_errs_pps(r, p, t);
                        if (err > 0)
                                errstr = "cpu-dest/err";
                        if (pps > 0)
                                printf(fmt_rx, "XDP-RX",
                                        i, pps, drop, err, errstr);
                }
                pps  = calc_pps(&rec->total, &prev->total, t);
                drop = calc_drop_pps(&rec->total, &prev->total, t);
                err  = calc_errs_pps(&rec->total, &prev->total, t);
                printf(fm2_rx, "XDP-RX", "total", pps, drop);
        }

        /* cpumap enqueue stats */
        for (to_cpu = 0; to_cpu < n_cpus; to_cpu++) {
                char *fmt = "%-15s %3d:%-3d %'-14.0f %'-11.0f %'-10.2f %s\n";
                char *fm2 = "%-15s %3s:%-3d %'-14.0f %'-11.0f %'-10.2f %s\n";
                char *errstr = "";

                rec  =  &stats_rec->enq[to_cpu];
                prev = &stats_prev->enq[to_cpu];
                t = calc_period(rec, prev);
                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];

                        pps  = calc_pps(r, p, t);
                        drop = calc_drop_pps(r, p, t);
                        err  = calc_errs_pps(r, p, t);
                        if (err > 0) {
                                errstr = "bulk-average";
                                err = pps / err; /* calc average bulk size */
                        }
                        if (pps > 0)
                                printf(fmt, "cpumap-enqueue",
                                       i, to_cpu, pps, drop, err, errstr);
                }
                pps = calc_pps(&rec->total, &prev->total, t);
                if (pps > 0) {
                        drop = calc_drop_pps(&rec->total, &prev->total, t);
                        err  = calc_errs_pps(&rec->total, &prev->total, t);
                        if (err > 0) {
                                errstr = "bulk-average";
                                err = pps / err; /* calc average bulk size */
                        }
                        printf(fm2, "cpumap-enqueue",
                               "sum", to_cpu, pps, drop, err, errstr);
                }
        }

        /* cpumap kthread stats */
        {
                char *fmt_k = "%-15s %-7d %'-14.0f %'-11.0f %'-10.0f %s\n";
                char *fm2_k = "%-15s %-7s %'-14.0f %'-11.0f %'-10.0f %s\n";
                char *e_str = "";

                rec  = &stats_rec->kthread;
                prev = &stats_prev->kthread;
                t = calc_period(rec, prev);
                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];

                        pps  = calc_pps(r, p, t);
                        drop = calc_drop_pps(r, p, t);
                        err  = calc_errs_pps(r, p, t);
                        if (err > 0)
                                e_str = "sched";
                        if (pps > 0)
                                printf(fmt_k, "cpumap_kthread",
                                       i, pps, drop, err, e_str);
                }
                pps = calc_pps(&rec->total, &prev->total, t);
                drop = calc_drop_pps(&rec->total, &prev->total, t);
                err  = calc_errs_pps(&rec->total, &prev->total, t);
                if (err > 0)
                        e_str = "sched-sum";
                printf(fm2_k, "cpumap_kthread", "total", pps, drop, err, e_str);
        }

        /* XDP redirect err tracepoints (very unlikely) */
        {
                char *fmt_err = "%-15s %-7d %'-14.0f %'-11.0f\n";
                char *fm2_err = "%-15s %-7s %'-14.0f %'-11.0f\n";

                rec  = &stats_rec->redir_err;
                prev = &stats_prev->redir_err;
                t = calc_period(rec, prev);
                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];

                        pps  = calc_pps(r, p, t);
                        drop = calc_drop_pps(r, p, t);
                        if (pps > 0)
                                printf(fmt_err, "redirect_err", i, pps, drop);
                }
                pps = calc_pps(&rec->total, &prev->total, t);
                drop = calc_drop_pps(&rec->total, &prev->total, t);
                printf(fm2_err, "redirect_err", "total", pps, drop);
        }

        /* XDP general exception tracepoints */
        {
                char *fmt_err = "%-15s %-7d %'-14.0f %'-11.0f\n";
                char *fm2_err = "%-15s %-7s %'-14.0f %'-11.0f\n";

                rec  = &stats_rec->exception;
                prev = &stats_prev->exception;
                t = calc_period(rec, prev);
                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];

                        pps  = calc_pps(r, p, t);
                        drop = calc_drop_pps(r, p, t);
                        if (pps > 0)
                                printf(fmt_err, "xdp_exception", i, pps, drop);
                }
                pps = calc_pps(&rec->total, &prev->total, t);
                drop = calc_drop_pps(&rec->total, &prev->total, t);
                printf(fm2_err, "xdp_exception", "total", pps, drop);
        }

        /* CPUMAP attached XDP program that runs on remote/destination CPU */
        if (mprog_enabled) {
                char *fmt_k = "%-15s %-7d %'-14.0f %'-11.0f %'-10.0f\n";
                char *fm2_k = "%-15s %-7s %'-14.0f %'-11.0f %'-10.0f\n";
                double xdp_pass, xdp_drop, xdp_redirect;

                printf("\n2nd remote XDP/eBPF prog_name: %s\n", mprog_name);
                printf("%-15s %-7s %-14s %-11s %-9s\n",
                       "XDP-cpumap", "CPU:to", "xdp-pass", "xdp-drop", "xdp-redir");

                rec  = &stats_rec->kthread;
                prev = &stats_prev->kthread;
                t = calc_period(rec, prev);
                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];

                        calc_xdp_pps(r, p, &xdp_pass, &xdp_drop,
                                     &xdp_redirect, t);
                        if (xdp_pass > 0 || xdp_drop > 0 || xdp_redirect > 0)
                                printf(fmt_k, "xdp-in-kthread", i, xdp_pass, xdp_drop,
                                       xdp_redirect);
                }
                calc_xdp_pps(&rec->total, &prev->total, &xdp_pass, &xdp_drop,
                             &xdp_redirect, t);
                printf(fm2_k, "xdp-in-kthread", "total", xdp_pass, xdp_drop, xdp_redirect);
        }

        printf("\n");
        fflush(stdout);
}

static void stats_collect(struct stats_record *rec)
{
        int fd, i;

        fd = map_fds[RX_CNT];
        map_collect_percpu(fd, 0, &rec->rx_cnt);

        fd = map_fds[REDIRECT_ERR_CNT];
        map_collect_percpu(fd, 1, &rec->redir_err);

        fd = map_fds[CPUMAP_ENQUEUE_CNT];
        for (i = 0; i < n_cpus; i++)
                map_collect_percpu(fd, i, &rec->enq[i]);

        fd = map_fds[CPUMAP_KTHREAD_CNT];
        map_collect_percpu(fd, 0, &rec->kthread);

        fd = map_fds[EXCEPTION_CNT];
        map_collect_percpu(fd, 0, &rec->exception);
}


/* Pointer swap trick */
static inline void swap(struct stats_record **a, struct stats_record **b)
{
        struct stats_record *tmp;

        tmp = *a;
        *a = *b;
        *b = tmp;
}

static int create_cpu_entry(__u32 cpu, struct bpf_cpumap_val *value,
                            __u32 avail_idx, bool new)
{
        __u32 curr_cpus_count = 0;
        __u32 key = 0;
        int ret;

        /* Add a CPU entry to cpumap, as this allocate a cpu entry in
         * the kernel for the cpu.
         */
        ret = bpf_map_update_elem(map_fds[CPU_MAP], &cpu, value, 0);
        if (ret) {
                fprintf(stderr, "Create CPU entry failed (err:%d)\n", ret);
                exit(EXIT_FAIL_BPF);
        }

        /* Inform bpf_prog's that a new CPU is available to select
         * from via some control maps.
         */
        ret = bpf_map_update_elem(map_fds[CPUS_AVAILABLE], &avail_idx, &cpu, 0);
        if (ret) {
                fprintf(stderr, "Add to avail CPUs failed\n");
                exit(EXIT_FAIL_BPF);
        }

        /* When not replacing/updating existing entry, bump the count */
        ret = bpf_map_lookup_elem(map_fds[CPUS_COUNT], &key, &curr_cpus_count);
        if (ret) {
                fprintf(stderr, "Failed reading curr cpus_count\n");
                exit(EXIT_FAIL_BPF);
        }
        if (new) {
                curr_cpus_count++;
                ret = bpf_map_update_elem(map_fds[CPUS_COUNT], &key,
                                          &curr_cpus_count, 0);
                if (ret) {
                        fprintf(stderr, "Failed write curr cpus_count\n");
                        exit(EXIT_FAIL_BPF);
                }
        }
        /* map_fd[7] = cpus_iterator */
        printf("%s CPU:%u as idx:%u qsize:%d prog_fd: %d (cpus_count:%u)\n",
               new ? "Add-new":"Replace", cpu, avail_idx,
               value->qsize, value->bpf_prog.fd, curr_cpus_count);

        return 0;
}

/* CPUs are zero-indexed. Thus, add a special sentinel default value
 * in map cpus_available to mark CPU index'es not configured
 */
static void mark_cpus_unavailable(void)
{
        __u32 invalid_cpu = n_cpus;
        int ret, i;

        for (i = 0; i < n_cpus; i++) {
                ret = bpf_map_update_elem(map_fds[CPUS_AVAILABLE], &i,
                                          &invalid_cpu, 0);
                if (ret) {
                        fprintf(stderr, "Failed marking CPU unavailable\n");
                        exit(EXIT_FAIL_BPF);
                }
        }
}

/* Stress cpumap management code by concurrently changing underlying cpumap */
static void stress_cpumap(struct bpf_cpumap_val *value)
{
        /* Changing qsize will cause kernel to free and alloc a new
         * bpf_cpu_map_entry, with an associated/complicated tear-down
         * procedure.
         */
        value->qsize = 1024;
        create_cpu_entry(1, value, 0, false);
        value->qsize = 8;
        create_cpu_entry(1, value, 0, false);
        value->qsize = 16000;
        create_cpu_entry(1, value, 0, false);
}

static void stats_poll(int interval, bool use_separators, char *prog_name,
                       char *mprog_name, struct bpf_cpumap_val *value,
                       bool stress_mode)
{
        struct stats_record *record, *prev;
        int mprog_fd;

        record = alloc_stats_record();
        prev   = alloc_stats_record();
        stats_collect(record);

        /* Trick to pretty printf with thousands separators use %' */
        if (use_separators)
                setlocale(LC_NUMERIC, "en_US");

        while (1) {
                swap(&prev, &record);
                mprog_fd = value->bpf_prog.fd;
                stats_collect(record);
                stats_print(record, prev, prog_name, mprog_name, mprog_fd);
                sleep(interval);
                if (stress_mode)
                        stress_cpumap(value);
        }

        free_stats_record(record);
        free_stats_record(prev);
}

static int init_tracepoints(struct bpf_object *obj)
{
        struct bpf_program *prog;

        bpf_object__for_each_program(prog, obj) {
                if (bpf_program__is_tracepoint(prog) != true)
                        continue;

                tp_links[tp_cnt] = bpf_program__attach(prog);
                if (libbpf_get_error(tp_links[tp_cnt])) {
                        tp_links[tp_cnt] = NULL;
                        return -EINVAL;
                }
                tp_cnt++;
        }

        return 0;
}

static int init_map_fds(struct bpf_object *obj)
{
        enum map_type type;

        for (type = 0; type < NUM_MAP; type++) {
                map_fds[type] =
                        bpf_object__find_map_fd_by_name(obj,
                                                        map_type_strings[type]);

                if (map_fds[type] < 0)
                        return -ENOENT;
        }

        return 0;
}

static int load_cpumap_prog(char *file_name, char *prog_name,
                            char *redir_interface, char *redir_map)
{
        struct bpf_prog_load_attr prog_load_attr = {
                .prog_type              = BPF_PROG_TYPE_XDP,
                .expected_attach_type   = BPF_XDP_CPUMAP,
                .file = file_name,
        };
        struct bpf_program *prog;
        struct bpf_object *obj;
        int fd;

        if (bpf_prog_load_xattr(&prog_load_attr, &obj, &fd))
                return -1;

        if (fd < 0) {
                fprintf(stderr, "ERR: bpf_prog_load_xattr: %s\n",
                        strerror(errno));
                return fd;
        }

        if (redir_interface && redir_map) {
                int err, map_fd, ifindex_out, key = 0;

                map_fd = bpf_object__find_map_fd_by_name(obj, redir_map);
                if (map_fd < 0)
                        return map_fd;

                ifindex_out = if_nametoindex(redir_interface);
                if (!ifindex_out)
                        return -1;

                err = bpf_map_update_elem(map_fd, &key, &ifindex_out, 0);
                if (err < 0)
                        return err;
        }

        prog = bpf_object__find_program_by_title(obj, prog_name);
        if (!prog) {
                fprintf(stderr, "bpf_object__find_program_by_title failed\n");
                return EXIT_FAIL;
        }

        return bpf_program__fd(prog);
}

int main(int argc, char **argv)
{
        char *prog_name = "xdp_cpu_map5_lb_hash_ip_pairs";
        char *mprog_filename = "xdp_redirect_kern.o";
        char *redir_interface = NULL, *redir_map = NULL;
        char *mprog_name = "xdp_redirect_dummy";
        bool mprog_disable = false;
        struct bpf_prog_load_attr prog_load_attr = {
                .prog_type      = BPF_PROG_TYPE_UNSPEC,
        };
        struct bpf_prog_info info = {};
        __u32 info_len = sizeof(info);
        struct bpf_cpumap_val value;
        bool use_separators = true;
        bool stress_mode = false;
        struct bpf_program *prog;
        struct bpf_object *obj;
        int err = EXIT_FAIL;
        char filename[256];
        int added_cpus = 0;
        int longindex = 0;
        int interval = 2;
        int add_cpu = -1;
        int opt, prog_fd;
        int *cpu, i;
        __u32 qsize;

        n_cpus = get_nprocs_conf();

        /* Notice: choosing he queue size is very important with the
         * ixgbe driver, because it's driver page recycling trick is
         * dependend on pages being returned quickly.  The number of
         * out-standing packets in the system must be less-than 2x
         * RX-ring size.
         */
        qsize = 128+64;

        snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
        prog_load_attr.file = filename;

        if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
                return err;

        if (prog_fd < 0) {
                fprintf(stderr, "ERR: bpf_prog_load_xattr: %s\n",
                        strerror(errno));
                return err;
        }

        if (init_tracepoints(obj) < 0) {
                fprintf(stderr, "ERR: bpf_program__attach failed\n");
                return err;
        }

        if (init_map_fds(obj) < 0) {
                fprintf(stderr, "bpf_object__find_map_fd_by_name failed\n");
                return err;
        }
        mark_cpus_unavailable();

        cpu = malloc(n_cpus * sizeof(int));
        if (!cpu) {
                fprintf(stderr, "failed to allocate cpu array\n");
                return err;
        }
        memset(cpu, 0, n_cpus * sizeof(int));

        /* Parse commands line args */
        while ((opt = getopt_long(argc, argv, "hSd:s:p:q:c:xzFf:e:r:m:",
                                  long_options, &longindex)) != -1) {
                switch (opt) {
                case 'd':
                        if (strlen(optarg) >= IF_NAMESIZE) {
                                fprintf(stderr, "ERR: --dev name too long\n");
                                goto error;
                        }
                        ifname = (char *)&ifname_buf;
                        strncpy(ifname, optarg, IF_NAMESIZE);
                        ifindex = if_nametoindex(ifname);
                        if (ifindex == 0) {
                                fprintf(stderr,
                                        "ERR: --dev name unknown err(%d):%s\n",
                                        errno, strerror(errno));
                                goto error;
                        }
                        break;
                case 's':
                        interval = atoi(optarg);
                        break;
                case 'S':
                        xdp_flags |= XDP_FLAGS_SKB_MODE;
                        break;
                case 'x':
                        stress_mode = true;
                        break;
                case 'z':
                        use_separators = false;
                        break;
                case 'p':
                        /* Selecting eBPF prog to load */
                        prog_name = optarg;
                        break;
                case 'n':
                        mprog_disable = true;
                        break;
                case 'f':
                        mprog_filename = optarg;
                        break;
                case 'e':
                        mprog_name = optarg;
                        break;
                case 'r':
                        redir_interface = optarg;
                        break;
                case 'm':
                        redir_map = optarg;
                        break;
                case 'c':
                        /* Add multiple CPUs */
                        add_cpu = strtoul(optarg, NULL, 0);
                        if (add_cpu >= n_cpus) {
                                fprintf(stderr,
                                "--cpu nr too large for cpumap err(%d):%s\n",
                                        errno, strerror(errno));
                                goto error;
                        }
                        cpu[added_cpus++] = add_cpu;
                        break;
                case 'q':
                        qsize = atoi(optarg);
                        break;
                case 'F':
                        xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
                        break;
                case 'h':
                error:
                default:
                        free(cpu);
                        usage(argv, obj);
                        return EXIT_FAIL_OPTION;
                }
        }

        if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
                xdp_flags |= XDP_FLAGS_DRV_MODE;

        /* Required option */
        if (ifindex == -1) {
                fprintf(stderr, "ERR: required option --dev missing\n");
                usage(argv, obj);
                err = EXIT_FAIL_OPTION;
                goto out;
        }
        /* Required option */
        if (add_cpu == -1) {
                fprintf(stderr, "ERR: required option --cpu missing\n");
                fprintf(stderr, " Specify multiple --cpu option to add more\n");
                usage(argv, obj);
                err = EXIT_FAIL_OPTION;
                goto out;
        }

        value.bpf_prog.fd = 0;
        if (!mprog_disable)
                value.bpf_prog.fd = load_cpumap_prog(mprog_filename, mprog_name,
                                                     redir_interface, redir_map);
        if (value.bpf_prog.fd < 0) {
                err = value.bpf_prog.fd;
                goto out;
        }
        value.qsize = qsize;

        for (i = 0; i < added_cpus; i++)
                create_cpu_entry(cpu[i], &value, i, true);

        /* Remove XDP program when program is interrupted or killed */
        signal(SIGINT, int_exit);
        signal(SIGTERM, int_exit);

        prog = bpf_object__find_program_by_title(obj, prog_name);
        if (!prog) {
                fprintf(stderr, "bpf_object__find_program_by_title failed\n");
                goto out;
        }

        prog_fd = bpf_program__fd(prog);
        if (prog_fd < 0) {
                fprintf(stderr, "bpf_program__fd failed\n");
                goto out;
        }

        if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
                fprintf(stderr, "link set xdp fd failed\n");
                err = EXIT_FAIL_XDP;
                goto out;
        }

        err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
        if (err) {
                printf("can't get prog info - %s\n", strerror(errno));
                goto out;
        }
        prog_id = info.id;

        stats_poll(interval, use_separators, prog_name, mprog_name,
                   &value, stress_mode);

        err = EXIT_OK;
out:
        free(cpu);
        return err;
}