root/samples/bpf/xdp_sample_user.c
// SPDX-License-Identifier: GPL-2.0-only
#define _GNU_SOURCE

#include <arpa/inet.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <linux/ethtool.h>
#include <linux/hashtable.h>
#include <linux/if_link.h>
#include <linux/jhash.h>
#include <linux/limits.h>
#include <linux/list.h>
#include <linux/sockios.h>
#include <locale.h>
#include <math.h>
#include <net/if.h>
#include <poll.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/signalfd.h>
#include <sys/sysinfo.h>
#include <sys/timerfd.h>
#include <sys/utsname.h>
#include <time.h>
#include <unistd.h>

#include "bpf_util.h"
#include "xdp_sample_user.h"

#define __sample_print(fmt, cond, ...)                                         \
        ({                                                                     \
                if (cond)                                                      \
                        printf(fmt, ##__VA_ARGS__);                            \
        })

#define print_always(fmt, ...) __sample_print(fmt, 1, ##__VA_ARGS__)
#define print_default(fmt, ...)                                                \
        __sample_print(fmt, sample_log_level & LL_DEFAULT, ##__VA_ARGS__)
#define __print_err(err, fmt, ...)                                             \
        ({                                                                     \
                __sample_print(fmt, err > 0 || sample_log_level & LL_DEFAULT,  \
                               ##__VA_ARGS__);                                 \
                sample_err_exp = sample_err_exp ? true : err > 0;              \
        })
#define print_err(err, fmt, ...) __print_err(err, fmt, ##__VA_ARGS__)

#define __COLUMN(x) "%'10" x " %-13s"
#define FMT_COLUMNf __COLUMN(".0f")
#define FMT_COLUMNd __COLUMN("d")
#define FMT_COLUMNl __COLUMN("llu")
#define RX(rx) rx, "rx/s"
#define PPS(pps) pps, "pkt/s"
#define DROP(drop) drop, "drop/s"
#define ERR(err) err, "error/s"
#define HITS(hits) hits, "hit/s"
#define XMIT(xmit) xmit, "xmit/s"
#define PASS(pass) pass, "pass/s"
#define REDIR(redir) redir, "redir/s"
#define NANOSEC_PER_SEC 1000000000 /* 10^9 */

#define XDP_UNKNOWN (XDP_REDIRECT + 1)
#define XDP_ACTION_MAX (XDP_UNKNOWN + 1)
#define XDP_REDIRECT_ERR_MAX 7

enum map_type {
        MAP_RX,
        MAP_REDIRECT_ERR,
        MAP_CPUMAP_ENQUEUE,
        MAP_CPUMAP_KTHREAD,
        MAP_EXCEPTION,
        MAP_DEVMAP_XMIT,
        MAP_DEVMAP_XMIT_MULTI,
        NUM_MAP,
};

enum log_level {
        LL_DEFAULT = 1U << 0,
        LL_SIMPLE = 1U << 1,
        LL_DEBUG = 1U << 2,
};

struct record {
        __u64 timestamp;
        struct datarec total;
        struct datarec *cpu;
};

struct map_entry {
        struct hlist_node node;
        __u64 pair;
        struct record val;
};

struct stats_record {
        struct record rx_cnt;
        struct record redir_err[XDP_REDIRECT_ERR_MAX];
        struct record kthread;
        struct record exception[XDP_ACTION_MAX];
        struct record devmap_xmit;
        DECLARE_HASHTABLE(xmit_map, 5);
        struct record enq[];
};

struct sample_output {
        struct {
                __u64 rx;
                __u64 redir;
                __u64 drop;
                __u64 drop_xmit;
                __u64 err;
                __u64 xmit;
        } totals;
        struct {
                union {
                        __u64 pps;
                        __u64 num;
                };
                __u64 drop;
                __u64 err;
        } rx_cnt;
        struct {
                __u64 suc;
                __u64 err;
        } redir_cnt;
        struct {
                __u64 hits;
        } except_cnt;
        struct {
                __u64 pps;
                __u64 drop;
                __u64 err;
                double bavg;
        } xmit_cnt;
};

struct xdp_desc {
        int ifindex;
        __u32 prog_id;
        int flags;
} sample_xdp_progs[32];

struct datarec *sample_mmap[NUM_MAP];
struct bpf_map *sample_map[NUM_MAP];
size_t sample_map_count[NUM_MAP];
enum log_level sample_log_level;
struct sample_output sample_out;
unsigned long sample_interval;
bool sample_err_exp;
int sample_xdp_cnt;
int sample_n_cpus;
int sample_sig_fd;
int sample_mask;

static const char *xdp_redirect_err_names[XDP_REDIRECT_ERR_MAX] = {
        /* Key=1 keeps unknown errors */
        "Success",
        "Unknown",
        "EINVAL",
        "ENETDOWN",
        "EMSGSIZE",
        "EOPNOTSUPP",
        "ENOSPC",
};

/* Keyed from Unknown */
static const char *xdp_redirect_err_help[XDP_REDIRECT_ERR_MAX - 1] = {
        "Unknown error",
        "Invalid redirection",
        "Device being redirected to is down",
        "Packet length too large for device",
        "Operation not supported",
        "No space in ptr_ring of cpumap kthread",
};

static const char *xdp_action_names[XDP_ACTION_MAX] = {
        [XDP_ABORTED]  = "XDP_ABORTED",
        [XDP_DROP]     = "XDP_DROP",
        [XDP_PASS]     = "XDP_PASS",
        [XDP_TX]       = "XDP_TX",
        [XDP_REDIRECT] = "XDP_REDIRECT",
        [XDP_UNKNOWN]  = "XDP_UNKNOWN",
};

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);
                return UINT64_MAX;
        }
        return (__u64)t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
}

static const char *action2str(int action)
{
        if (action < XDP_ACTION_MAX)
                return xdp_action_names[action];
        return NULL;
}

static void sample_print_help(int mask)
{
        printf("Output format description\n\n"
               "By default, redirect success statistics are disabled, use -s to enable.\n"
               "The terse output mode is default, verbose mode can be activated using -v\n"
               "Use SIGQUIT (Ctrl + \\) to switch the mode dynamically at runtime\n\n"
               "Terse mode displays at most the following fields:\n"
               "  rx/s        Number of packets received per second\n"
               "  redir/s     Number of packets successfully redirected per second\n"
               "  err,drop/s  Aggregated count of errors per second (including dropped packets)\n"
               "  xmit/s      Number of packets transmitted on the output device per second\n\n"
               "Output description for verbose mode:\n"
               "  FIELD                 DESCRIPTION\n");

        if (mask & SAMPLE_RX_CNT) {
                printf("  receive\t\tDisplays the number of packets received & errors encountered\n"
                       " \t\t\tWhenever an error or packet drop occurs, details of per CPU error\n"
                       " \t\t\tand drop statistics will be expanded inline in terse mode.\n"
                       " \t\t\t\tpkt/s     - Packets received per second\n"
                       " \t\t\t\tdrop/s    - Packets dropped per second\n"
                       " \t\t\t\terror/s   - Errors encountered per second\n\n");
        }
        if (mask & (SAMPLE_REDIRECT_CNT | SAMPLE_REDIRECT_ERR_CNT)) {
                printf("  redirect\t\tDisplays the number of packets successfully redirected\n"
                       "  \t\t\tErrors encountered are expanded under redirect_err field\n"
                       "  \t\t\tNote that passing -s to enable it has a per packet overhead\n"
                       "  \t\t\t\tredir/s   - Packets redirected successfully per second\n\n"
                       "  redirect_err\t\tDisplays the number of packets that failed redirection\n"
                       "  \t\t\tThe errno is expanded under this field with per CPU count\n"
                       "  \t\t\tThe recognized errors are:\n");

                for (int i = 2; i < XDP_REDIRECT_ERR_MAX; i++)
                        printf("\t\t\t  %s: %s\n", xdp_redirect_err_names[i],
                               xdp_redirect_err_help[i - 1]);

                printf("  \n\t\t\t\terror/s   - Packets that failed redirection per second\n\n");
        }

        if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT) {
                printf("  enqueue to cpu N\tDisplays the number of packets enqueued to bulk queue of CPU N\n"
                       "  \t\t\tExpands to cpu:FROM->N to display enqueue stats for each CPU enqueuing to CPU N\n"
                       "  \t\t\tReceived packets can be associated with the CPU redirect program is enqueuing \n"
                       "  \t\t\tpackets to.\n"
                       "  \t\t\t\tpkt/s    - Packets enqueued per second from other CPU to CPU N\n"
                       "  \t\t\t\tdrop/s   - Packets dropped when trying to enqueue to CPU N\n"
                       "  \t\t\t\tbulk-avg - Average number of packets processed for each event\n\n");
        }

        if (mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
                printf("  kthread\t\tDisplays the number of packets processed in CPUMAP kthread for each CPU\n"
                       "  \t\t\tPackets consumed from ptr_ring in kthread, and its xdp_stats (after calling \n"
                       "  \t\t\tCPUMAP bpf prog) are expanded below this. xdp_stats are expanded as a total and\n"
                       "  \t\t\tthen per-CPU to associate it to each CPU's pinned CPUMAP kthread.\n"
                       "  \t\t\t\tpkt/s    - Packets consumed per second from ptr_ring\n"
                       "  \t\t\t\tdrop/s   - Packets dropped per second in kthread\n"
                       "  \t\t\t\tsched    - Number of times kthread called schedule()\n\n"
                       "  \t\t\txdp_stats (also expands to per-CPU counts)\n"
                       "  \t\t\t\tpass/s  - XDP_PASS count for CPUMAP program execution\n"
                       "  \t\t\t\tdrop/s  - XDP_DROP count for CPUMAP program execution\n"
                       "  \t\t\t\tredir/s - XDP_REDIRECT count for CPUMAP program execution\n\n");
        }

        if (mask & SAMPLE_EXCEPTION_CNT) {
                printf("  xdp_exception\t\tDisplays xdp_exception tracepoint events\n"
                       "  \t\t\tThis can occur due to internal driver errors, unrecognized\n"
                       "  \t\t\tXDP actions and due to explicit user trigger by use of XDP_ABORTED\n"
                       "  \t\t\tEach action is expanded below this field with its count\n"
                       "  \t\t\t\thit/s     - Number of times the tracepoint was hit per second\n\n");
        }

        if (mask & SAMPLE_DEVMAP_XMIT_CNT) {
                printf("  devmap_xmit\t\tDisplays devmap_xmit tracepoint events\n"
                       "  \t\t\tThis tracepoint is invoked for successful transmissions on output\n"
                       "  \t\t\tdevice but these statistics are not available for generic XDP mode,\n"
                       "  \t\t\thence they will be omitted from the output when using SKB mode\n"
                       "  \t\t\t\txmit/s    - Number of packets that were transmitted per second\n"
                       "  \t\t\t\tdrop/s    - Number of packets that failed transmissions per second\n"
                       "  \t\t\t\tdrv_err/s - Number of internal driver errors per second\n"
                       "  \t\t\t\tbulk-avg  - Average number of packets processed for each event\n\n");
        }
}

void sample_usage(char *argv[], const struct option *long_options,
                  const char *doc, int mask, bool error)
{
        int i;

        if (!error)
                sample_print_help(mask);

        printf("\n%s\nOption for %s:\n", doc, argv[0]);
        for (i = 0; long_options[i].name != 0; i++) {
                printf(" --%-15s", long_options[i].name);
                if (long_options[i].flag != NULL)
                        printf(" flag (internal value: %d)",
                               *long_options[i].flag);
                else
                        printf("\t short-option: -%c", long_options[i].val);
                printf("\n");
        }
        printf("\n");
}

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

        array = calloc(nr_cpus, sizeof(*array));
        if (!array) {
                fprintf(stderr, "Failed to allocate memory (nr_cpus: %u)\n",
                        nr_cpus);
                return NULL;
        }
        return array;
}

static int map_entry_init(struct map_entry *e, __u64 pair)
{
        e->pair = pair;
        INIT_HLIST_NODE(&e->node);
        e->val.timestamp = gettime();
        e->val.cpu = alloc_record_per_cpu();
        if (!e->val.cpu)
                return -ENOMEM;
        return 0;
}

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

        /* 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 = READ_ONCE(values[i].processed);
                rec->cpu[i].dropped = READ_ONCE(values[i].dropped);
                rec->cpu[i].issue = READ_ONCE(values[i].issue);
                rec->cpu[i].xdp_pass = READ_ONCE(values[i].xdp_pass);
                rec->cpu[i].xdp_drop = READ_ONCE(values[i].xdp_drop);
                rec->cpu[i].xdp_redirect = READ_ONCE(values[i].xdp_redirect);

                sum_processed += rec->cpu[i].processed;
                sum_dropped += rec->cpu[i].dropped;
                sum_issue += rec->cpu[i].issue;
                sum_xdp_pass += rec->cpu[i].xdp_pass;
                sum_xdp_drop += rec->cpu[i].xdp_drop;
                sum_xdp_redirect += rec->cpu[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;
}

static int map_collect_percpu_devmap(int map_fd, struct stats_record *rec)
{
        unsigned int nr_cpus = bpf_num_possible_cpus();
        __u32 batch, count = 32;
        struct datarec *values;
        bool init = false;
        __u64 *keys;
        int i, ret;

        keys = calloc(count, sizeof(__u64));
        if (!keys)
                return -ENOMEM;
        values = calloc(count * nr_cpus, sizeof(struct datarec));
        if (!values) {
                free(keys);
                return -ENOMEM;
        }

        for (;;) {
                bool exit = false;

                ret = bpf_map_lookup_batch(map_fd, init ? &batch : NULL, &batch,
                                           keys, values, &count, NULL);
                if (ret < 0 && errno != ENOENT)
                        break;
                if (errno == ENOENT)
                        exit = true;

                init = true;
                for (i = 0; i < count; i++) {
                        struct map_entry *e, *x = NULL;
                        __u64 pair = keys[i];
                        struct datarec *arr;

                        arr = &values[i * nr_cpus];
                        hash_for_each_possible(rec->xmit_map, e, node, pair) {
                                if (e->pair == pair) {
                                        x = e;
                                        break;
                                }
                        }
                        if (!x) {
                                x = calloc(1, sizeof(*x));
                                if (!x)
                                        goto cleanup;
                                if (map_entry_init(x, pair) < 0) {
                                        free(x);
                                        goto cleanup;
                                }
                                hash_add(rec->xmit_map, &x->node, pair);
                        }
                        map_collect_percpu(arr, &x->val);
                }

                if (exit)
                        break;
                count = 32;
        }

        free(values);
        free(keys);
        return 0;
cleanup:
        free(values);
        free(keys);
        return -ENOMEM;
}

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

        rec = calloc(1, sizeof(*rec) + sample_n_cpus * sizeof(struct record));
        if (!rec) {
                fprintf(stderr, "Failed to allocate memory\n");
                return NULL;
        }

        if (sample_mask & SAMPLE_RX_CNT) {
                rec->rx_cnt.cpu = alloc_record_per_cpu();
                if (!rec->rx_cnt.cpu) {
                        fprintf(stderr,
                                "Failed to allocate rx_cnt per-CPU array\n");
                        goto end_rec;
                }
        }
        if (sample_mask & (SAMPLE_REDIRECT_CNT | SAMPLE_REDIRECT_ERR_CNT)) {
                for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++) {
                        rec->redir_err[i].cpu = alloc_record_per_cpu();
                        if (!rec->redir_err[i].cpu) {
                                fprintf(stderr,
                                        "Failed to allocate redir_err per-CPU array for "
                                        "\"%s\" case\n",
                                        xdp_redirect_err_names[i]);
                                while (i--)
                                        free(rec->redir_err[i].cpu);
                                goto end_rx_cnt;
                        }
                }
        }
        if (sample_mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
                rec->kthread.cpu = alloc_record_per_cpu();
                if (!rec->kthread.cpu) {
                        fprintf(stderr,
                                "Failed to allocate kthread per-CPU array\n");
                        goto end_redir;
                }
        }
        if (sample_mask & SAMPLE_EXCEPTION_CNT) {
                for (i = 0; i < XDP_ACTION_MAX; i++) {
                        rec->exception[i].cpu = alloc_record_per_cpu();
                        if (!rec->exception[i].cpu) {
                                fprintf(stderr,
                                        "Failed to allocate exception per-CPU array for "
                                        "\"%s\" case\n",
                                        action2str(i));
                                while (i--)
                                        free(rec->exception[i].cpu);
                                goto end_kthread;
                        }
                }
        }
        if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT) {
                rec->devmap_xmit.cpu = alloc_record_per_cpu();
                if (!rec->devmap_xmit.cpu) {
                        fprintf(stderr,
                                "Failed to allocate devmap_xmit per-CPU array\n");
                        goto end_exception;
                }
        }
        if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
                hash_init(rec->xmit_map);
        if (sample_mask & SAMPLE_CPUMAP_ENQUEUE_CNT) {
                for (i = 0; i < sample_n_cpus; i++) {
                        rec->enq[i].cpu = alloc_record_per_cpu();
                        if (!rec->enq[i].cpu) {
                                fprintf(stderr,
                                        "Failed to allocate enqueue per-CPU array for "
                                        "CPU %d\n",
                                        i);
                                while (i--)
                                        free(rec->enq[i].cpu);
                                goto end_devmap_xmit;
                        }
                }
        }

        return rec;

end_devmap_xmit:
        free(rec->devmap_xmit.cpu);
end_exception:
        for (i = 0; i < XDP_ACTION_MAX; i++)
                free(rec->exception[i].cpu);
end_kthread:
        free(rec->kthread.cpu);
end_redir:
        for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++)
                free(rec->redir_err[i].cpu);
end_rx_cnt:
        free(rec->rx_cnt.cpu);
end_rec:
        free(rec);
        return NULL;
}

static void free_stats_record(struct stats_record *r)
{
        struct hlist_node *tmp;
        struct map_entry *e;
        int i;

        for (i = 0; i < sample_n_cpus; i++)
                free(r->enq[i].cpu);
        hash_for_each_safe(r->xmit_map, i, tmp, e, node) {
                hash_del(&e->node);
                free(e->val.cpu);
                free(e);
        }
        free(r->devmap_xmit.cpu);
        for (i = 0; i < XDP_ACTION_MAX; i++)
                free(r->exception[i].cpu);
        free(r->kthread.cpu);
        for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++)
                free(r->redir_err[i].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 double sample_round(double val)
{
        if (val - floor(val) < 0.5)
                return floor(val);
        return ceil(val);
}

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 = sample_round(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 = sample_round(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 = sample_round(packets / period_);
        }
        return pps;
}

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

        if (period_ > 0) {
                packets = r->info - p->info;
                pps = sample_round(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_get_rx_cnt(struct stats_record *stats_rec,
                             struct stats_record *stats_prev,
                             unsigned int nr_cpus, struct sample_output *out)
{
        struct record *rec, *prev;
        double t, pps, drop, err;
        int i;

        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];
                char str[64];

                pps = calc_pps(r, p, t);
                drop = calc_drop_pps(r, p, t);
                err = calc_errs_pps(r, p, t);
                if (!pps && !drop && !err)
                        continue;

                snprintf(str, sizeof(str), "cpu:%d", i);
                print_default("    %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
                              "\n",
                              str, PPS(pps), DROP(drop), ERR(err));
        }

        if (out) {
                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);

                out->rx_cnt.pps = pps;
                out->rx_cnt.drop = drop;
                out->rx_cnt.err = err;
                out->totals.rx += pps;
                out->totals.drop += drop;
                out->totals.err += err;
        }
}

static void stats_get_cpumap_enqueue(struct stats_record *stats_rec,
                                     struct stats_record *stats_prev,
                                     unsigned int nr_cpus)
{
        struct record *rec, *prev;
        double t, pps, drop, err;
        int i, to_cpu;

        /* cpumap enqueue stats */
        for (to_cpu = 0; to_cpu < sample_n_cpus; to_cpu++) {
                rec = &stats_rec->enq[to_cpu];
                prev = &stats_prev->enq[to_cpu];
                t = calc_period(rec, prev);

                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 (pps > 0 || drop > 0) {
                        char str[64];

                        snprintf(str, sizeof(str), "enqueue to cpu %d", to_cpu);

                        if (err > 0)
                                err = pps / err; /* calc average bulk size */

                        print_err(drop,
                                  "  %-20s " FMT_COLUMNf FMT_COLUMNf __COLUMN(
                                          ".2f") "\n",
                                  str, PPS(pps), DROP(drop), err, "bulk-avg");
                }

                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];
                        char str[64];

                        pps = calc_pps(r, p, t);
                        drop = calc_drop_pps(r, p, t);
                        err = calc_errs_pps(r, p, t);
                        if (!pps && !drop && !err)
                                continue;

                        snprintf(str, sizeof(str), "cpu:%d->%d", i, to_cpu);
                        if (err > 0)
                                err = pps / err; /* calc average bulk size */
                        print_default(
                                "    %-18s " FMT_COLUMNf FMT_COLUMNf __COLUMN(
                                        ".2f") "\n",
                                str, PPS(pps), DROP(drop), err, "bulk-avg");
                }
        }
}

static void stats_get_cpumap_remote(struct stats_record *stats_rec,
                                    struct stats_record *stats_prev,
                                    unsigned int nr_cpus)
{
        double xdp_pass, xdp_drop, xdp_redirect;
        struct record *rec, *prev;
        double t;
        int i;

        rec = &stats_rec->kthread;
        prev = &stats_prev->kthread;
        t = calc_period(rec, prev);

        calc_xdp_pps(&rec->total, &prev->total, &xdp_pass, &xdp_drop,
                     &xdp_redirect, t);
        if (xdp_pass || xdp_drop || xdp_redirect) {
                print_err(xdp_drop,
                          "    %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf "\n",
                          "xdp_stats", PASS(xdp_pass), DROP(xdp_drop),
                          REDIR(xdp_redirect));
        }

        for (i = 0; i < nr_cpus; i++) {
                struct datarec *r = &rec->cpu[i];
                struct datarec *p = &prev->cpu[i];
                char str[64];

                calc_xdp_pps(r, p, &xdp_pass, &xdp_drop, &xdp_redirect, t);
                if (!xdp_pass && !xdp_drop && !xdp_redirect)
                        continue;

                snprintf(str, sizeof(str), "cpu:%d", i);
                print_default("      %-16s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
                              "\n",
                              str, PASS(xdp_pass), DROP(xdp_drop),
                              REDIR(xdp_redirect));
        }
}

static void stats_get_cpumap_kthread(struct stats_record *stats_rec,
                                     struct stats_record *stats_prev,
                                     unsigned int nr_cpus)
{
        struct record *rec, *prev;
        double t, pps, drop, err;
        int i;

        rec = &stats_rec->kthread;
        prev = &stats_prev->kthread;
        t = calc_period(rec, prev);

        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);

        print_err(drop, "  %-20s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf "\n",
                  pps ? "kthread total" : "kthread", PPS(pps), DROP(drop), err,
                  "sched");

        for (i = 0; i < nr_cpus; i++) {
                struct datarec *r = &rec->cpu[i];
                struct datarec *p = &prev->cpu[i];
                char str[64];

                pps = calc_pps(r, p, t);
                drop = calc_drop_pps(r, p, t);
                err = calc_errs_pps(r, p, t);
                if (!pps && !drop && !err)
                        continue;

                snprintf(str, sizeof(str), "cpu:%d", i);
                print_default("    %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
                              "\n",
                              str, PPS(pps), DROP(drop), err, "sched");
        }
}

static void stats_get_redirect_cnt(struct stats_record *stats_rec,
                                   struct stats_record *stats_prev,
                                   unsigned int nr_cpus,
                                   struct sample_output *out)
{
        struct record *rec, *prev;
        double t, pps;
        int i;

        rec = &stats_rec->redir_err[0];
        prev = &stats_prev->redir_err[0];
        t = calc_period(rec, prev);
        for (i = 0; i < nr_cpus; i++) {
                struct datarec *r = &rec->cpu[i];
                struct datarec *p = &prev->cpu[i];
                char str[64];

                pps = calc_pps(r, p, t);
                if (!pps)
                        continue;

                snprintf(str, sizeof(str), "cpu:%d", i);
                print_default("    %-18s " FMT_COLUMNf "\n", str, REDIR(pps));
        }

        if (out) {
                pps = calc_pps(&rec->total, &prev->total, t);
                out->redir_cnt.suc = pps;
                out->totals.redir += pps;
        }
}

static void stats_get_redirect_err_cnt(struct stats_record *stats_rec,
                                       struct stats_record *stats_prev,
                                       unsigned int nr_cpus,
                                       struct sample_output *out)
{
        struct record *rec, *prev;
        double t, drop, sum = 0;
        int rec_i, i;

        for (rec_i = 1; rec_i < XDP_REDIRECT_ERR_MAX; rec_i++) {
                char str[64];

                rec = &stats_rec->redir_err[rec_i];
                prev = &stats_prev->redir_err[rec_i];
                t = calc_period(rec, prev);

                drop = calc_drop_pps(&rec->total, &prev->total, t);
                if (drop > 0 && !out) {
                        snprintf(str, sizeof(str),
                                 sample_log_level & LL_DEFAULT ? "%s total" :
                                                                       "%s",
                                 xdp_redirect_err_names[rec_i]);
                        print_err(drop, "    %-18s " FMT_COLUMNf "\n", str,
                                  ERR(drop));
                }

                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *r = &rec->cpu[i];
                        struct datarec *p = &prev->cpu[i];
                        double drop;

                        drop = calc_drop_pps(r, p, t);
                        if (!drop)
                                continue;

                        snprintf(str, sizeof(str), "cpu:%d", i);
                        print_default("       %-16s" FMT_COLUMNf "\n", str,
                                      ERR(drop));
                }

                sum += drop;
        }

        if (out) {
                out->redir_cnt.err = sum;
                out->totals.err += sum;
        }
}

static void stats_get_exception_cnt(struct stats_record *stats_rec,
                                    struct stats_record *stats_prev,
                                    unsigned int nr_cpus,
                                    struct sample_output *out)
{
        double t, drop, sum = 0;
        struct record *rec, *prev;
        int rec_i, i;

        for (rec_i = 0; rec_i < XDP_ACTION_MAX; rec_i++) {
                rec = &stats_rec->exception[rec_i];
                prev = &stats_prev->exception[rec_i];
                t = calc_period(rec, prev);

                drop = calc_drop_pps(&rec->total, &prev->total, t);
                /* Fold out errors after heading */
                sum += drop;

                if (drop > 0 && !out) {
                        print_always("    %-18s " FMT_COLUMNf "\n",
                                     action2str(rec_i), ERR(drop));

                        for (i = 0; i < nr_cpus; i++) {
                                struct datarec *r = &rec->cpu[i];
                                struct datarec *p = &prev->cpu[i];
                                char str[64];
                                double drop;

                                drop = calc_drop_pps(r, p, t);
                                if (!drop)
                                        continue;

                                snprintf(str, sizeof(str), "cpu:%d", i);
                                print_default("       %-16s" FMT_COLUMNf "\n",
                                              str, ERR(drop));
                        }
                }
        }

        if (out) {
                out->except_cnt.hits = sum;
                out->totals.err += sum;
        }
}

static void stats_get_devmap_xmit(struct stats_record *stats_rec,
                                  struct stats_record *stats_prev,
                                  unsigned int nr_cpus,
                                  struct sample_output *out)
{
        double pps, drop, info, err;
        struct record *rec, *prev;
        double t;
        int i;

        rec = &stats_rec->devmap_xmit;
        prev = &stats_prev->devmap_xmit;
        t = calc_period(rec, prev);
        for (i = 0; i < nr_cpus; i++) {
                struct datarec *r = &rec->cpu[i];
                struct datarec *p = &prev->cpu[i];
                char str[64];

                pps = calc_pps(r, p, t);
                drop = calc_drop_pps(r, p, t);
                err = calc_errs_pps(r, p, t);

                if (!pps && !drop && !err)
                        continue;

                snprintf(str, sizeof(str), "cpu:%d", i);
                info = calc_info_pps(r, p, t);
                if (info > 0)
                        info = (pps + drop) / info; /* calc avg bulk */
                print_default("     %-18s" FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
                                      __COLUMN(".2f") "\n",
                              str, XMIT(pps), DROP(drop), err, "drv_err/s",
                              info, "bulk-avg");
        }
        if (out) {
                pps = calc_pps(&rec->total, &prev->total, t);
                drop = calc_drop_pps(&rec->total, &prev->total, t);
                info = calc_info_pps(&rec->total, &prev->total, t);
                if (info > 0)
                        info = (pps + drop) / info; /* calc avg bulk */
                err = calc_errs_pps(&rec->total, &prev->total, t);

                out->xmit_cnt.pps = pps;
                out->xmit_cnt.drop = drop;
                out->xmit_cnt.bavg = info;
                out->xmit_cnt.err = err;
                out->totals.xmit += pps;
                out->totals.drop_xmit += drop;
                out->totals.err += err;
        }
}

static void stats_get_devmap_xmit_multi(struct stats_record *stats_rec,
                                        struct stats_record *stats_prev,
                                        unsigned int nr_cpus,
                                        struct sample_output *out,
                                        bool xmit_total)
{
        double pps, drop, info, err;
        struct map_entry *entry;
        struct record *r, *p;
        double t;
        int bkt;

        hash_for_each(stats_rec->xmit_map, bkt, entry, node) {
                struct map_entry *e, *x = NULL;
                char ifname_from[IFNAMSIZ];
                char ifname_to[IFNAMSIZ];
                const char *fstr, *tstr;
                unsigned long prev_time;
                struct record beg = {};
                __u32 from_idx, to_idx;
                char str[128];
                __u64 pair;
                int i;

                prev_time = sample_interval * NANOSEC_PER_SEC;

                pair = entry->pair;
                from_idx = pair >> 32;
                to_idx = pair & 0xFFFFFFFF;

                r = &entry->val;
                beg.timestamp = r->timestamp - prev_time;

                /* Find matching entry from stats_prev map */
                hash_for_each_possible(stats_prev->xmit_map, e, node, pair) {
                        if (e->pair == pair) {
                                x = e;
                                break;
                        }
                }
                if (x)
                        p = &x->val;
                else
                        p = &beg;
                t = calc_period(r, p);
                pps = calc_pps(&r->total, &p->total, t);
                drop = calc_drop_pps(&r->total, &p->total, t);
                info = calc_info_pps(&r->total, &p->total, t);
                if (info > 0)
                        info = (pps + drop) / info; /* calc avg bulk */
                err = calc_errs_pps(&r->total, &p->total, t);

                if (out) {
                        /* We are responsible for filling out totals */
                        out->totals.xmit += pps;
                        out->totals.drop_xmit += drop;
                        out->totals.err += err;
                        continue;
                }

                fstr = tstr = NULL;
                if (if_indextoname(from_idx, ifname_from))
                        fstr = ifname_from;
                if (if_indextoname(to_idx, ifname_to))
                        tstr = ifname_to;

                snprintf(str, sizeof(str), "xmit %s->%s", fstr ?: "?",
                         tstr ?: "?");
                /* Skip idle streams of redirection */
                if (pps || drop || err) {
                        print_err(drop,
                                  "  %-20s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
                                  __COLUMN(".2f") "\n", str, XMIT(pps), DROP(drop),
                                  err, "drv_err/s", info, "bulk-avg");
                }

                for (i = 0; i < nr_cpus; i++) {
                        struct datarec *rc = &r->cpu[i];
                        struct datarec *pc, p_beg = {};
                        char str[64];

                        pc = p == &beg ? &p_beg : &p->cpu[i];

                        pps = calc_pps(rc, pc, t);
                        drop = calc_drop_pps(rc, pc, t);
                        err = calc_errs_pps(rc, pc, t);

                        if (!pps && !drop && !err)
                                continue;

                        snprintf(str, sizeof(str), "cpu:%d", i);
                        info = calc_info_pps(rc, pc, t);
                        if (info > 0)
                                info = (pps + drop) / info; /* calc avg bulk */

                        print_default("     %-18s" FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
                                      __COLUMN(".2f") "\n", str, XMIT(pps),
                                      DROP(drop), err, "drv_err/s", info, "bulk-avg");
                }
        }
}

static void stats_print(const char *prefix, int mask, struct stats_record *r,
                        struct stats_record *p, struct sample_output *out)
{
        int nr_cpus = libbpf_num_possible_cpus();
        const char *str;

        print_always("%-23s", prefix ?: "Summary");
        if (mask & SAMPLE_RX_CNT)
                print_always(FMT_COLUMNl, RX(out->totals.rx));
        if (mask & SAMPLE_REDIRECT_CNT)
                print_always(FMT_COLUMNl, REDIR(out->totals.redir));
        printf(FMT_COLUMNl,
               out->totals.err + out->totals.drop + out->totals.drop_xmit,
               "err,drop/s");
        if (mask & SAMPLE_DEVMAP_XMIT_CNT ||
            mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
                printf(FMT_COLUMNl, XMIT(out->totals.xmit));
        printf("\n");

        if (mask & SAMPLE_RX_CNT) {
                str = (sample_log_level & LL_DEFAULT) && out->rx_cnt.pps ?
                                    "receive total" :
                                    "receive";
                print_err((out->rx_cnt.err || out->rx_cnt.drop),
                          "  %-20s " FMT_COLUMNl FMT_COLUMNl FMT_COLUMNl "\n",
                          str, PPS(out->rx_cnt.pps), DROP(out->rx_cnt.drop),
                          ERR(out->rx_cnt.err));

                stats_get_rx_cnt(r, p, nr_cpus, NULL);
        }

        if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT)
                stats_get_cpumap_enqueue(r, p, nr_cpus);

        if (mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
                stats_get_cpumap_kthread(r, p, nr_cpus);
                stats_get_cpumap_remote(r, p, nr_cpus);
        }

        if (mask & SAMPLE_REDIRECT_CNT) {
                str = out->redir_cnt.suc ? "redirect total" : "redirect";
                print_default("  %-20s " FMT_COLUMNl "\n", str,
                              REDIR(out->redir_cnt.suc));

                stats_get_redirect_cnt(r, p, nr_cpus, NULL);
        }

        if (mask & SAMPLE_REDIRECT_ERR_CNT) {
                str = (sample_log_level & LL_DEFAULT) && out->redir_cnt.err ?
                                    "redirect_err total" :
                                    "redirect_err";
                print_err(out->redir_cnt.err, "  %-20s " FMT_COLUMNl "\n", str,
                          ERR(out->redir_cnt.err));

                stats_get_redirect_err_cnt(r, p, nr_cpus, NULL);
        }

        if (mask & SAMPLE_EXCEPTION_CNT) {
                str = out->except_cnt.hits ? "xdp_exception total" :
                                                   "xdp_exception";

                print_err(out->except_cnt.hits, "  %-20s " FMT_COLUMNl "\n", str,
                          HITS(out->except_cnt.hits));

                stats_get_exception_cnt(r, p, nr_cpus, NULL);
        }

        if (mask & SAMPLE_DEVMAP_XMIT_CNT) {
                str = (sample_log_level & LL_DEFAULT) && out->xmit_cnt.pps ?
                                    "devmap_xmit total" :
                                    "devmap_xmit";

                print_err(out->xmit_cnt.err || out->xmit_cnt.drop,
                          "  %-20s " FMT_COLUMNl FMT_COLUMNl FMT_COLUMNl
                                  __COLUMN(".2f") "\n",
                          str, XMIT(out->xmit_cnt.pps),
                          DROP(out->xmit_cnt.drop), out->xmit_cnt.err,
                          "drv_err/s", out->xmit_cnt.bavg, "bulk-avg");

                stats_get_devmap_xmit(r, p, nr_cpus, NULL);
        }

        if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
                stats_get_devmap_xmit_multi(r, p, nr_cpus, NULL,
                                            mask & SAMPLE_DEVMAP_XMIT_CNT);

        if (sample_log_level & LL_DEFAULT ||
            ((sample_log_level & LL_SIMPLE) && sample_err_exp)) {
                sample_err_exp = false;
                printf("\n");
        }
}

int sample_setup_maps(struct bpf_map **maps)
{
        sample_n_cpus = libbpf_num_possible_cpus();

        for (int i = 0; i < MAP_DEVMAP_XMIT_MULTI; i++) {
                sample_map[i] = maps[i];

                switch (i) {
                case MAP_RX:
                case MAP_CPUMAP_KTHREAD:
                case MAP_DEVMAP_XMIT:
                        sample_map_count[i] = sample_n_cpus;
                        break;
                case MAP_REDIRECT_ERR:
                        sample_map_count[i] =
                                XDP_REDIRECT_ERR_MAX * sample_n_cpus;
                        break;
                case MAP_EXCEPTION:
                        sample_map_count[i] = XDP_ACTION_MAX * sample_n_cpus;
                case MAP_CPUMAP_ENQUEUE:
                        sample_map_count[i] = sample_n_cpus * sample_n_cpus;
                        break;
                default:
                        return -EINVAL;
                }
                if (bpf_map__set_max_entries(sample_map[i], sample_map_count[i]) < 0)
                        return -errno;
        }
        sample_map[MAP_DEVMAP_XMIT_MULTI] = maps[MAP_DEVMAP_XMIT_MULTI];
        return 0;
}

static int sample_setup_maps_mappings(void)
{
        for (int i = 0; i < MAP_DEVMAP_XMIT_MULTI; i++) {
                size_t size = sample_map_count[i] * sizeof(struct datarec);

                sample_mmap[i] = mmap(NULL, size, PROT_READ | PROT_WRITE,
                                      MAP_SHARED, bpf_map__fd(sample_map[i]), 0);
                if (sample_mmap[i] == MAP_FAILED)
                        return -errno;
        }
        return 0;
}

int __sample_init(int mask)
{
        sigset_t st;

        sigemptyset(&st);
        sigaddset(&st, SIGQUIT);
        sigaddset(&st, SIGINT);
        sigaddset(&st, SIGTERM);

        if (sigprocmask(SIG_BLOCK, &st, NULL) < 0)
                return -errno;

        sample_sig_fd = signalfd(-1, &st, SFD_CLOEXEC | SFD_NONBLOCK);
        if (sample_sig_fd < 0)
                return -errno;

        sample_mask = mask;

        return sample_setup_maps_mappings();
}

static int __sample_remove_xdp(int ifindex, __u32 prog_id, int xdp_flags)
{
        __u32 cur_prog_id = 0;
        int ret;

        if (prog_id) {
                ret = bpf_xdp_query_id(ifindex, xdp_flags, &cur_prog_id);
                if (ret < 0)
                        return -errno;

                if (prog_id != cur_prog_id) {
                        print_always(
                                "Program on ifindex %d does not match installed "
                                "program, skipping unload\n",
                                ifindex);
                        return -ENOENT;
                }
        }

        return bpf_xdp_detach(ifindex, xdp_flags, NULL);
}

int sample_install_xdp(struct bpf_program *xdp_prog, int ifindex, bool generic,
                       bool force)
{
        int ret, xdp_flags = 0;
        __u32 prog_id = 0;

        if (sample_xdp_cnt == 32) {
                fprintf(stderr,
                        "Total limit for installed XDP programs in a sample reached\n");
                return -ENOTSUP;
        }

        xdp_flags |= !force ? XDP_FLAGS_UPDATE_IF_NOEXIST : 0;
        xdp_flags |= generic ? XDP_FLAGS_SKB_MODE : XDP_FLAGS_DRV_MODE;
        ret = bpf_xdp_attach(ifindex, bpf_program__fd(xdp_prog), xdp_flags, NULL);
        if (ret < 0) {
                ret = -errno;
                fprintf(stderr,
                        "Failed to install program \"%s\" on ifindex %d, mode = %s, "
                        "force = %s: %s\n",
                        bpf_program__name(xdp_prog), ifindex,
                        generic ? "skb" : "native", force ? "true" : "false",
                        strerror(-ret));
                return ret;
        }

        ret = bpf_xdp_query_id(ifindex, xdp_flags, &prog_id);
        if (ret < 0) {
                ret = -errno;
                fprintf(stderr,
                        "Failed to get XDP program id for ifindex %d, removing program: %s\n",
                        ifindex, strerror(errno));
                __sample_remove_xdp(ifindex, 0, xdp_flags);
                return ret;
        }
        sample_xdp_progs[sample_xdp_cnt++] =
                (struct xdp_desc){ ifindex, prog_id, xdp_flags };

        return 0;
}

static void sample_summary_print(void)
{
        double num = sample_out.rx_cnt.num;

        if (sample_out.totals.rx) {
                double pkts = sample_out.totals.rx;

                print_always("  Packets received    : %'-10llu\n",
                             sample_out.totals.rx);
                print_always("  Average packets/s   : %'-10.0f\n",
                             sample_round(pkts / num));
        }
        if (sample_out.totals.redir) {
                double pkts = sample_out.totals.redir;

                print_always("  Packets redirected  : %'-10llu\n",
                             sample_out.totals.redir);
                print_always("  Average redir/s     : %'-10.0f\n",
                             sample_round(pkts / num));
        }
        if (sample_out.totals.drop)
                print_always("  Rx dropped          : %'-10llu\n",
                             sample_out.totals.drop);
        if (sample_out.totals.drop_xmit)
                print_always("  Tx dropped          : %'-10llu\n",
                             sample_out.totals.drop_xmit);
        if (sample_out.totals.err)
                print_always("  Errors recorded     : %'-10llu\n",
                             sample_out.totals.err);
        if (sample_out.totals.xmit) {
                double pkts = sample_out.totals.xmit;

                print_always("  Packets transmitted : %'-10llu\n",
                             sample_out.totals.xmit);
                print_always("  Average transmit/s  : %'-10.0f\n",
                             sample_round(pkts / num));
        }
}

void sample_exit(int status)
{
        size_t size;

        for (int i = 0; i < NUM_MAP; i++) {
                size = sample_map_count[i] * sizeof(**sample_mmap);
                munmap(sample_mmap[i], size);
        }
        while (sample_xdp_cnt--) {
                int i = sample_xdp_cnt, ifindex, xdp_flags;
                __u32 prog_id;

                prog_id = sample_xdp_progs[i].prog_id;
                ifindex = sample_xdp_progs[i].ifindex;
                xdp_flags = sample_xdp_progs[i].flags;

                __sample_remove_xdp(ifindex, prog_id, xdp_flags);
        }
        sample_summary_print();
        close(sample_sig_fd);
        exit(status);
}

static int sample_stats_collect(struct stats_record *rec)
{
        int i;

        if (sample_mask & SAMPLE_RX_CNT)
                map_collect_percpu(sample_mmap[MAP_RX], &rec->rx_cnt);

        if (sample_mask & SAMPLE_REDIRECT_CNT)
                map_collect_percpu(sample_mmap[MAP_REDIRECT_ERR], &rec->redir_err[0]);

        if (sample_mask & SAMPLE_REDIRECT_ERR_CNT) {
                for (i = 1; i < XDP_REDIRECT_ERR_MAX; i++)
                        map_collect_percpu(&sample_mmap[MAP_REDIRECT_ERR][i * sample_n_cpus],
                                           &rec->redir_err[i]);
        }

        if (sample_mask & SAMPLE_CPUMAP_ENQUEUE_CNT)
                for (i = 0; i < sample_n_cpus; i++)
                        map_collect_percpu(&sample_mmap[MAP_CPUMAP_ENQUEUE][i * sample_n_cpus],
                                           &rec->enq[i]);

        if (sample_mask & SAMPLE_CPUMAP_KTHREAD_CNT)
                map_collect_percpu(sample_mmap[MAP_CPUMAP_KTHREAD],
                                   &rec->kthread);

        if (sample_mask & SAMPLE_EXCEPTION_CNT)
                for (i = 0; i < XDP_ACTION_MAX; i++)
                        map_collect_percpu(&sample_mmap[MAP_EXCEPTION][i * sample_n_cpus],
                                           &rec->exception[i]);

        if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT)
                map_collect_percpu(sample_mmap[MAP_DEVMAP_XMIT], &rec->devmap_xmit);

        if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) {
                if (map_collect_percpu_devmap(bpf_map__fd(sample_map[MAP_DEVMAP_XMIT_MULTI]), rec) < 0)
                        return -EINVAL;
        }
        return 0;
}

static void sample_summary_update(struct sample_output *out)
{
        sample_out.totals.rx += out->totals.rx;
        sample_out.totals.redir += out->totals.redir;
        sample_out.totals.drop += out->totals.drop;
        sample_out.totals.drop_xmit += out->totals.drop_xmit;
        sample_out.totals.err += out->totals.err;
        sample_out.totals.xmit += out->totals.xmit;
        sample_out.rx_cnt.num++;
}

static void sample_stats_print(int mask, struct stats_record *cur,
                               struct stats_record *prev, char *prog_name)
{
        struct sample_output out = {};

        if (mask & SAMPLE_RX_CNT)
                stats_get_rx_cnt(cur, prev, 0, &out);
        if (mask & SAMPLE_REDIRECT_CNT)
                stats_get_redirect_cnt(cur, prev, 0, &out);
        if (mask & SAMPLE_REDIRECT_ERR_CNT)
                stats_get_redirect_err_cnt(cur, prev, 0, &out);
        if (mask & SAMPLE_EXCEPTION_CNT)
                stats_get_exception_cnt(cur, prev, 0, &out);
        if (mask & SAMPLE_DEVMAP_XMIT_CNT)
                stats_get_devmap_xmit(cur, prev, 0, &out);
        else if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
                stats_get_devmap_xmit_multi(cur, prev, 0, &out,
                                            mask & SAMPLE_DEVMAP_XMIT_CNT);
        sample_summary_update(&out);

        stats_print(prog_name, mask, cur, prev, &out);
}

void sample_switch_mode(void)
{
        sample_log_level ^= LL_DEBUG - 1;
}

static int sample_signal_cb(void)
{
        struct signalfd_siginfo si;
        int r;

        r = read(sample_sig_fd, &si, sizeof(si));
        if (r < 0)
                return -errno;

        switch (si.ssi_signo) {
        case SIGQUIT:
                sample_switch_mode();
                printf("\n");
                break;
        default:
                printf("\n");
                return 1;
        }

        return 0;
}

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

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

static int sample_timer_cb(int timerfd, struct stats_record **rec,
                           struct stats_record **prev)
{
        char line[64] = "Summary";
        int ret;
        __u64 t;

        ret = read(timerfd, &t, sizeof(t));
        if (ret < 0)
                return -errno;

        swap(prev, rec);
        ret = sample_stats_collect(*rec);
        if (ret < 0)
                return ret;

        if (sample_xdp_cnt == 2 && !(sample_mask & SAMPLE_SKIP_HEADING)) {
                char fi[IFNAMSIZ];
                char to[IFNAMSIZ];
                const char *f, *t;

                f = t = NULL;
                if (if_indextoname(sample_xdp_progs[0].ifindex, fi))
                        f = fi;
                if (if_indextoname(sample_xdp_progs[1].ifindex, to))
                        t = to;

                snprintf(line, sizeof(line), "%s->%s", f ?: "?", t ?: "?");
        }

        sample_stats_print(sample_mask, *rec, *prev, line);
        return 0;
}

int sample_run(int interval, void (*post_cb)(void *), void *ctx)
{
        struct timespec ts = { interval, 0 };
        struct itimerspec its = { ts, ts };
        struct stats_record *rec, *prev;
        struct pollfd pfd[2] = {};
        int timerfd, ret;

        if (!interval) {
                fprintf(stderr, "Incorrect interval 0\n");
                return -EINVAL;
        }
        sample_interval = interval;
        /* Pretty print numbers */
        setlocale(LC_NUMERIC, "en_US.UTF-8");

        timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC | TFD_NONBLOCK);
        if (timerfd < 0)
                return -errno;
        timerfd_settime(timerfd, 0, &its, NULL);

        pfd[0].fd = sample_sig_fd;
        pfd[0].events = POLLIN;

        pfd[1].fd = timerfd;
        pfd[1].events = POLLIN;

        ret = -ENOMEM;
        rec = alloc_stats_record();
        if (!rec)
                goto end;
        prev = alloc_stats_record();
        if (!prev)
                goto end_rec;

        ret = sample_stats_collect(rec);
        if (ret < 0)
                goto end_rec_prev;

        for (;;) {
                ret = poll(pfd, 2, -1);
                if (ret < 0) {
                        if (errno == EINTR)
                                continue;
                        else
                                break;
                }

                if (pfd[0].revents & POLLIN)
                        ret = sample_signal_cb();
                else if (pfd[1].revents & POLLIN)
                        ret = sample_timer_cb(timerfd, &rec, &prev);

                if (ret)
                        break;

                if (post_cb)
                        post_cb(ctx);
        }

end_rec_prev:
        free_stats_record(prev);
end_rec:
        free_stats_record(rec);
end:
        close(timerfd);

        return ret;
}

const char *get_driver_name(int ifindex)
{
        struct ethtool_drvinfo drv = {};
        char ifname[IF_NAMESIZE];
        static char drvname[32];
        struct ifreq ifr = {};
        int fd, r = 0;

        fd = socket(AF_INET, SOCK_DGRAM, 0);
        if (fd < 0)
                return "[error]";

        if (!if_indextoname(ifindex, ifname))
                goto end;

        drv.cmd = ETHTOOL_GDRVINFO;
        safe_strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
        ifr.ifr_data = (void *)&drv;

        r = ioctl(fd, SIOCETHTOOL, &ifr);
        if (r)
                goto end;

        safe_strncpy(drvname, drv.driver, sizeof(drvname));

        close(fd);
        return drvname;

end:
        r = errno;
        close(fd);
        return r == EOPNOTSUPP ? "loopback" : "[error]";
}

int get_mac_addr(int ifindex, void *mac_addr)
{
        char ifname[IF_NAMESIZE];
        struct ifreq ifr = {};
        int fd, r;

        fd = socket(AF_INET, SOCK_DGRAM, 0);
        if (fd < 0)
                return -errno;

        if (!if_indextoname(ifindex, ifname)) {
                r = -errno;
                goto end;
        }

        safe_strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));

        r = ioctl(fd, SIOCGIFHWADDR, &ifr);
        if (r) {
                r = -errno;
                goto end;
        }

        memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));

end:
        close(fd);
        return r;
}

__attribute__((constructor)) static void sample_ctor(void)
{
        if (libbpf_set_strict_mode(LIBBPF_STRICT_ALL) < 0) {
                fprintf(stderr, "Failed to set libbpf strict mode: %s\n",
                        strerror(errno));
                /* Just exit, nothing to cleanup right now */
                exit(EXIT_FAIL_BPF);
        }
}