--- /dev/null
+/* XDP monitor tool, based on tracepoints
+ *
+ * Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
+ */
+#include <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+struct bpf_map_def SEC("maps") redirect_err_cnt = {
+ .type = BPF_MAP_TYPE_PERCPU_ARRAY,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(u64),
+ .max_entries = 2,
+ /* TODO: have entries for all possible errno's */
+};
+
+/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_redirect/format
+ * Code in: kernel/include/trace/events/xdp.h
+ */
+struct xdp_redirect_ctx {
+ unsigned short common_type; // offset:0; size:2; signed:0;
+ unsigned char common_flags; // offset:2; size:1; signed:0;
+ unsigned char common_preempt_count;// offset:3; size:1; signed:0;
+ int common_pid; // offset:4; size:4; signed:1;
+
+ int prog_id; // offset:8; size:4; signed:1;
+ u32 act; // offset:12 size:4; signed:0;
+ int ifindex; // offset:16 size:4; signed:1;
+ int err; // offset:20 size:4; signed:1;
+ int to_ifindex; // offset:24 size:4; signed:1;
+ u32 map_id; // offset:28 size:4; signed:0;
+ int map_index; // offset:32 size:4; signed:1;
+}; // offset:36
+
+enum {
+ XDP_REDIRECT_SUCCESS = 0,
+ XDP_REDIRECT_ERROR = 1
+};
+
+static __always_inline
+int xdp_redirect_collect_stat(struct xdp_redirect_ctx *ctx)
+{
+ u32 key = XDP_REDIRECT_ERROR;
+ int err = ctx->err;
+ u64 *cnt;
+
+ if (!err)
+ key = XDP_REDIRECT_SUCCESS;
+
+ cnt = bpf_map_lookup_elem(&redirect_err_cnt, &key);
+ if (!cnt)
+ return 0;
+ *cnt += 1;
+
+ return 0; /* Indicate event was filtered (no further processing)*/
+ /*
+ * Returning 1 here would allow e.g. a perf-record tracepoint
+ * to see and record these events, but it doesn't work well
+ * in-practice as stopping perf-record also unload this
+ * bpf_prog. Plus, there is additional overhead of doing so.
+ */
+}
+
+SEC("tracepoint/xdp/xdp_redirect_err")
+int trace_xdp_redirect_err(struct xdp_redirect_ctx *ctx)
+{
+ return xdp_redirect_collect_stat(ctx);
+}
+
+
+SEC("tracepoint/xdp/xdp_redirect_map_err")
+int trace_xdp_redirect_map_err(struct xdp_redirect_ctx *ctx)
+{
+ return xdp_redirect_collect_stat(ctx);
+}
+
+/* Likely unloaded when prog starts */
+SEC("tracepoint/xdp/xdp_redirect")
+int trace_xdp_redirect(struct xdp_redirect_ctx *ctx)
+{
+ return xdp_redirect_collect_stat(ctx);
+}
+
+/* Likely unloaded when prog starts */
+SEC("tracepoint/xdp/xdp_redirect_map")
+int trace_xdp_redirect_map(struct xdp_redirect_ctx *ctx)
+{
+ return xdp_redirect_collect_stat(ctx);
+}
--- /dev/null
+/* Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
+ */
+static const char *__doc__=
+ "XDP monitor tool, based on tracepoints\n"
+;
+
+static const char *__doc_err_only__=
+ " NOTICE: Only tracking XDP redirect errors\n"
+ " Enable TX success stats via '--stats'\n"
+ " (which comes with a per packet processing overhead)\n"
+;
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <locale.h>
+
+#include <getopt.h>
+#include <net/if.h>
+#include <time.h>
+
+#include "libbpf.h"
+#include "bpf_load.h"
+#include "bpf_util.h"
+
+static int verbose = 1;
+static bool debug = false;
+
+static const struct option long_options[] = {
+ {"help", no_argument, NULL, 'h' },
+ {"debug", no_argument, NULL, 'D' },
+ {"stats", no_argument, NULL, 'S' },
+ {"sec", required_argument, NULL, 's' },
+ {0, 0, NULL, 0 }
+};
+
+static void usage(char *argv[])
+{
+ 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(" --%-15s", long_options[i].name);
+ if (long_options[i].flag != NULL)
+ printf(" flag (internal value:%d)",
+ *long_options[i].flag);
+ else
+ printf("(internal short-option: -%c)",
+ long_options[i].val);
+ printf("\n");
+ }
+ printf("\n");
+}
+
+#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
+__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_FAILURE);
+ }
+ return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
+}
+
+enum {
+ REDIR_SUCCESS = 0,
+ REDIR_ERROR = 1,
+};
+#define REDIR_RES_MAX 2
+static const char *redir_names[REDIR_RES_MAX] = {
+ [REDIR_SUCCESS] = "Success",
+ [REDIR_ERROR] = "Error",
+};
+static const char *err2str(int err)
+{
+ if (err < REDIR_RES_MAX)
+ return redir_names[err];
+ return NULL;
+}
+
+struct record {
+ __u64 counter;
+ __u64 timestamp;
+};
+
+struct stats_record {
+ struct record xdp_redir[REDIR_RES_MAX];
+};
+
+static void stats_print_headers(bool err_only)
+{
+ if (err_only)
+ printf("\n%s\n", __doc_err_only__);
+
+ printf("%-14s %-10s %-18s %-9s\n",
+ "XDP_REDIRECT", "pps ", "pps-human-readable", "measure-period");
+}
+
+static void stats_print(struct stats_record *rec,
+ struct stats_record *prev,
+ bool err_only)
+{
+ int i = 0;
+
+ if (err_only)
+ i = REDIR_ERROR;
+
+ for (; i < REDIR_RES_MAX; i++) {
+ struct record *r = &rec->xdp_redir[i];
+ struct record *p = &prev->xdp_redir[i];
+ __u64 period = 0;
+ __u64 packets = 0;
+ double pps = 0;
+ double period_ = 0;
+
+ if (p->timestamp) {
+ packets = r->counter - p->counter;
+ period = r->timestamp - p->timestamp;
+ if (period > 0) {
+ period_ = ((double) period / NANOSEC_PER_SEC);
+ pps = packets / period_;
+ }
+ }
+
+ printf("%-14s %-10.0f %'-18.0f %f\n",
+ err2str(i), pps, pps, period_);
+ }
+}
+
+static __u64 get_key32_value64_percpu(int fd, __u32 key)
+{
+ /* For percpu maps, userspace gets a value per possible CPU */
+ unsigned int nr_cpus = bpf_num_possible_cpus();
+ __u64 values[nr_cpus];
+ __u64 sum = 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 0;
+ }
+
+ /* Sum values from each CPU */
+ for (i = 0; i < nr_cpus; i++) {
+ sum += values[i];
+ }
+ return sum;
+}
+
+static bool stats_collect(int fd, struct stats_record *rec)
+{
+ int i;
+
+ /* TODO: Detect if someone unloaded the perf event_fd's, as
+ * this can happen by someone running perf-record -e
+ */
+
+ for (i = 0; i < REDIR_RES_MAX; i++) {
+ rec->xdp_redir[i].timestamp = gettime();
+ rec->xdp_redir[i].counter = get_key32_value64_percpu(fd, i);
+ }
+ return true;
+}
+
+static void stats_poll(int interval, bool err_only)
+{
+ struct stats_record rec, prev;
+ int map_fd;
+
+ memset(&rec, 0, sizeof(rec));
+
+ /* Trick to pretty printf with thousands separators use %' */
+ setlocale(LC_NUMERIC, "en_US");
+
+ /* Header */
+ if (verbose)
+ printf("\n%s", __doc__);
+
+ /* TODO Need more advanced stats on error types */
+ if (verbose)
+ printf(" - Stats map: %s\n", map_data[0].name);
+ map_fd = map_data[0].fd;
+
+ stats_print_headers(err_only);
+ fflush(stdout);
+
+ while (1) {
+ memcpy(&prev, &rec, sizeof(rec));
+ stats_collect(map_fd, &rec);
+ stats_print(&rec, &prev, err_only);
+ fflush(stdout);
+ sleep(interval);
+ }
+}
+
+void print_bpf_prog_info(void)
+{
+ int i;
+
+ /* Prog info */
+ printf("Loaded BPF prog have %d bpf program(s)\n", prog_cnt);
+ for (i = 0; i < prog_cnt; i++) {
+ printf(" - prog_fd[%d] = fd(%d)\n", i, prog_fd[i]);
+ }
+
+ /* Maps info */
+ printf("Loaded BPF prog have %d map(s)\n", map_data_count);
+ for (i = 0; i < map_data_count; i++) {
+ char *name = map_data[i].name;
+ int fd = map_data[i].fd;
+
+ printf(" - map_data[%d] = fd(%d) name:%s\n", i, fd, name);
+ }
+
+ /* Event info */
+ printf("Searching for (max:%d) event file descriptor(s)\n", prog_cnt);
+ for (i = 0; i < prog_cnt; i++) {
+ if (event_fd[i] != -1)
+ printf(" - event_fd[%d] = fd(%d)\n", i, event_fd[i]);
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int longindex = 0, opt;
+ int ret = EXIT_SUCCESS;
+ char bpf_obj_file[256];
+
+ /* Default settings: */
+ bool errors_only = true;
+ int interval = 2;
+
+ snprintf(bpf_obj_file, sizeof(bpf_obj_file), "%s_kern.o", argv[0]);
+
+ /* Parse commands line args */
+ while ((opt = getopt_long(argc, argv, "h",
+ long_options, &longindex)) != -1) {
+ switch (opt) {
+ case 'D':
+ debug = true;
+ break;
+ case 'S':
+ errors_only = false;
+ break;
+ case 's':
+ interval = atoi(optarg);
+ break;
+ case 'h':
+ default:
+ usage(argv);
+ return EXIT_FAILURE;
+ }
+ }
+
+ if (load_bpf_file(bpf_obj_file)) {
+ printf("ERROR - bpf_log_buf: %s", bpf_log_buf);
+ return 1;
+ }
+ if (!prog_fd[0]) {
+ printf("ERROR - load_bpf_file: %s\n", strerror(errno));
+ return 1;
+ }
+
+ if (debug) {
+ print_bpf_prog_info();
+ }
+
+ /* Unload/stop tracepoint event by closing fd's */
+ if (errors_only) {
+ /* The prog_fd[i] and event_fd[i] depend on the
+ * order the functions was defined in _kern.c
+ */
+ close(event_fd[2]); /* tracepoint/xdp/xdp_redirect */
+ close(prog_fd[2]); /* func: trace_xdp_redirect */
+ close(event_fd[3]); /* tracepoint/xdp/xdp_redirect_map */
+ close(prog_fd[3]); /* func: trace_xdp_redirect_map */
+ }
+
+ stats_poll(interval, errors_only);
+
+ return ret;
+}