| 1 | |
| 2 | #include <linux/unistd.h>
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| 3 | #include <linux/bpf.h>
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| 4 |
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| 5 | #include <stdlib.h>
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| 6 | #include <stdio.h>
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| 7 | #include <unistd.h>
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| 8 | #include <string.h>
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| 9 | #include <errno.h>
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| 10 | #include <arpa/inet.h>
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| 11 |
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| 12 | #include <bpf/bpf.h>
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| 13 | #include "bpf_util.h"
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| 14 |
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| 15 | #define MAX_INDEX 64
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| 16 | #define MAX_STARS 38
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| 17 |
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| 18 | static void stars(char *str, long val, long max, int width)
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| 19 | {
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| 20 | int i;
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| 21 |
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| 22 | for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
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| 23 | str[i] = '*';
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| 24 | if (val > max)
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| 25 | str[i - 1] = '+';
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| 26 | str[i] = '\0';
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| 27 | }
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| 28 |
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| 29 | int main(int argc, char **argv)
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| 30 | {
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| 31 | unsigned int nr_cpus = bpf_num_possible_cpus();
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| 32 | const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map";
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| 33 | uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {};
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| 34 | uint64_t key = 0, next_key, max_key = 0;
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| 35 | char starstr[MAX_STARS];
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| 36 | int i, map_fd;
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| 37 |
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| 38 | map_fd = bpf_obj_get(map_filename);
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| 39 | if (map_fd < 0) {
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| 40 | fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
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| 41 | map_filename, strerror(errno), errno);
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| 42 | return -1;
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| 43 | }
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| 44 |
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| 45 | while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
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| 46 | if (next_key >= MAX_INDEX) {
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| 47 | fprintf(stderr, "Key %lu out of bounds\n", next_key);
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| 48 | continue;
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| 49 | }
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| 50 |
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| 51 | bpf_map_lookup_elem(map_fd, &next_key, values);
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| 52 |
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| 53 | sum = 0;
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| 54 | for (i = 0; i < nr_cpus; i++)
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| 55 | sum += values[i];
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| 56 |
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| 57 | data[next_key] = sum;
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| 58 | if (sum && next_key > max_key)
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| 59 | max_key = next_key;
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| 60 |
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| 61 | if (sum > max_value)
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| 62 | max_value = sum;
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| 63 |
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| 64 | key = next_key;
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| 65 | }
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| 66 |
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| 67 | for (i = 1; i <= max_key + 1; i++) {
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| 68 | stars(starstr, data[i - 1], max_value, MAX_STARS);
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| 69 | printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
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| 70 | (1l << i) >> 1, (1l << i) - 1, data[i - 1],
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| 71 | MAX_STARS, starstr);
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| 72 | }
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| 73 |
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| 74 | close(map_fd);
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| 75 |
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| 76 | return 0;
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| 77 | }
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