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- // SPDX-License-Identifier: GPL-2.0
- /* Copyright (c) 2019 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * Example program for Host Bandwidth Managment
- *
- * This program loads a cgroup skb BPF program to enforce cgroup output
- * (egress) or input (ingress) bandwidth limits.
- *
- * USAGE: hbm [-d] [-l] [-n <id>] [-r <rate>] [-s] [-t <secs>] [-w] [-h] [prog]
- * Where:
- * -d Print BPF trace debug buffer
- * -l Also limit flows doing loopback
- * -n <#> To create cgroup \"/hbm#\" and attach prog
- * Default is /hbm1
- * --no_cn Do not return cn notifications
- * -r <rate> Rate limit in Mbps
- * -s Get HBM stats (marked, dropped, etc.)
- * -t <time> Exit after specified seconds (default is 0)
- * -w Work conserving flag. cgroup can increase its bandwidth
- * beyond the rate limit specified while there is available
- * bandwidth. Current implementation assumes there is only
- * NIC (eth0), but can be extended to support multiple NICs.
- * Currrently only supported for egress.
- * -h Print this info
- * prog BPF program file name. Name defaults to hbm_out_kern.o
- */
- #define _GNU_SOURCE
- #include <stdio.h>
- #include <stdlib.h>
- #include <assert.h>
- #include <sys/time.h>
- #include <unistd.h>
- #include <errno.h>
- #include <fcntl.h>
- #include <linux/unistd.h>
- #include <linux/compiler.h>
- #include <linux/bpf.h>
- #include <bpf/bpf.h>
- #include <getopt.h>
- #include "cgroup_helpers.h"
- #include "hbm.h"
- #include "bpf_util.h"
- #include <bpf/libbpf.h>
- bool outFlag = true;
- int minRate = 1000; /* cgroup rate limit in Mbps */
- int rate = 1000; /* can grow if rate conserving is enabled */
- int dur = 1;
- bool stats_flag;
- bool loopback_flag;
- bool debugFlag;
- bool work_conserving_flag;
- bool no_cn_flag;
- bool edt_flag;
- static void Usage(void);
- static void read_trace_pipe2(void);
- static void do_error(char *msg, bool errno_flag);
- #define DEBUGFS "/sys/kernel/debug/tracing/"
- static struct bpf_program *bpf_prog;
- static struct bpf_object *obj;
- static int queue_stats_fd;
- static void read_trace_pipe2(void)
- {
- int trace_fd;
- FILE *outf;
- char *outFname = "hbm_out.log";
- trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
- if (trace_fd < 0) {
- printf("Error opening trace_pipe\n");
- return;
- }
- // Future support of ingress
- // if (!outFlag)
- // outFname = "hbm_in.log";
- outf = fopen(outFname, "w");
- if (outf == NULL)
- printf("Error creating %s\n", outFname);
- while (1) {
- static char buf[4097];
- ssize_t sz;
- sz = read(trace_fd, buf, sizeof(buf) - 1);
- if (sz > 0) {
- buf[sz] = 0;
- puts(buf);
- if (outf != NULL) {
- fprintf(outf, "%s\n", buf);
- fflush(outf);
- }
- }
- }
- }
- static void do_error(char *msg, bool errno_flag)
- {
- if (errno_flag)
- printf("ERROR: %s, errno: %d\n", msg, errno);
- else
- printf("ERROR: %s\n", msg);
- exit(1);
- }
- static int prog_load(char *prog)
- {
- struct bpf_program *pos;
- const char *sec_name;
- obj = bpf_object__open_file(prog, NULL);
- if (libbpf_get_error(obj)) {
- printf("ERROR: opening BPF object file failed\n");
- return 1;
- }
- /* load BPF program */
- if (bpf_object__load(obj)) {
- printf("ERROR: loading BPF object file failed\n");
- goto err;
- }
- bpf_object__for_each_program(pos, obj) {
- sec_name = bpf_program__section_name(pos);
- if (sec_name && !strcmp(sec_name, "cgroup_skb/egress")) {
- bpf_prog = pos;
- break;
- }
- }
- if (!bpf_prog) {
- printf("ERROR: finding a prog in obj file failed\n");
- goto err;
- }
- queue_stats_fd = bpf_object__find_map_fd_by_name(obj, "queue_stats");
- if (queue_stats_fd < 0) {
- printf("ERROR: finding a map in obj file failed\n");
- goto err;
- }
- return 0;
- err:
- bpf_object__close(obj);
- return 1;
- }
- static int run_bpf_prog(char *prog, int cg_id)
- {
- struct hbm_queue_stats qstats = {0};
- char cg_dir[100], cg_pin_path[100];
- struct bpf_link *link = NULL;
- int key = 0;
- int cg1 = 0;
- int rc = 0;
- sprintf(cg_dir, "/hbm%d", cg_id);
- rc = prog_load(prog);
- if (rc != 0)
- return rc;
- if (setup_cgroup_environment()) {
- printf("ERROR: setting cgroup environment\n");
- goto err;
- }
- cg1 = create_and_get_cgroup(cg_dir);
- if (!cg1) {
- printf("ERROR: create_and_get_cgroup\n");
- goto err;
- }
- if (join_cgroup(cg_dir)) {
- printf("ERROR: join_cgroup\n");
- goto err;
- }
- qstats.rate = rate;
- qstats.stats = stats_flag ? 1 : 0;
- qstats.loopback = loopback_flag ? 1 : 0;
- qstats.no_cn = no_cn_flag ? 1 : 0;
- if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY)) {
- printf("ERROR: Could not update map element\n");
- goto err;
- }
- if (!outFlag)
- bpf_program__set_expected_attach_type(bpf_prog, BPF_CGROUP_INET_INGRESS);
- link = bpf_program__attach_cgroup(bpf_prog, cg1);
- if (libbpf_get_error(link)) {
- fprintf(stderr, "ERROR: bpf_program__attach_cgroup failed\n");
- goto err;
- }
- sprintf(cg_pin_path, "/sys/fs/bpf/hbm%d", cg_id);
- rc = bpf_link__pin(link, cg_pin_path);
- if (rc < 0) {
- printf("ERROR: bpf_link__pin failed: %d\n", rc);
- goto err;
- }
- if (work_conserving_flag) {
- struct timeval t0, t_last, t_new;
- FILE *fin;
- unsigned long long last_eth_tx_bytes, new_eth_tx_bytes;
- signed long long last_cg_tx_bytes, new_cg_tx_bytes;
- signed long long delta_time, delta_bytes, delta_rate;
- int delta_ms;
- #define DELTA_RATE_CHECK 10000 /* in us */
- #define RATE_THRESHOLD 9500000000 /* 9.5 Gbps */
- bpf_map_lookup_elem(queue_stats_fd, &key, &qstats);
- if (gettimeofday(&t0, NULL) < 0)
- do_error("gettimeofday failed", true);
- t_last = t0;
- fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", "r");
- if (fscanf(fin, "%llu", &last_eth_tx_bytes) != 1)
- do_error("fscanf fails", false);
- fclose(fin);
- last_cg_tx_bytes = qstats.bytes_total;
- while (true) {
- usleep(DELTA_RATE_CHECK);
- if (gettimeofday(&t_new, NULL) < 0)
- do_error("gettimeofday failed", true);
- delta_ms = (t_new.tv_sec - t0.tv_sec) * 1000 +
- (t_new.tv_usec - t0.tv_usec)/1000;
- if (delta_ms > dur * 1000)
- break;
- delta_time = (t_new.tv_sec - t_last.tv_sec) * 1000000 +
- (t_new.tv_usec - t_last.tv_usec);
- if (delta_time == 0)
- continue;
- t_last = t_new;
- fin = fopen("/sys/class/net/eth0/statistics/tx_bytes",
- "r");
- if (fscanf(fin, "%llu", &new_eth_tx_bytes) != 1)
- do_error("fscanf fails", false);
- fclose(fin);
- printf(" new_eth_tx_bytes:%llu\n",
- new_eth_tx_bytes);
- bpf_map_lookup_elem(queue_stats_fd, &key, &qstats);
- new_cg_tx_bytes = qstats.bytes_total;
- delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes;
- last_eth_tx_bytes = new_eth_tx_bytes;
- delta_rate = (delta_bytes * 8000000) / delta_time;
- printf("%5d - eth_rate:%.1fGbps cg_rate:%.3fGbps",
- delta_ms, delta_rate/1000000000.0,
- rate/1000.0);
- if (delta_rate < RATE_THRESHOLD) {
- /* can increase cgroup rate limit, but first
- * check if we are using the current limit.
- * Currently increasing by 6.25%, unknown
- * if that is the optimal rate.
- */
- int rate_diff100;
- delta_bytes = new_cg_tx_bytes -
- last_cg_tx_bytes;
- last_cg_tx_bytes = new_cg_tx_bytes;
- delta_rate = (delta_bytes * 8000000) /
- delta_time;
- printf(" rate:%.3fGbps",
- delta_rate/1000000000.0);
- rate_diff100 = (((long long)rate)*1000000 -
- delta_rate) * 100 /
- (((long long) rate) * 1000000);
- printf(" rdiff:%d", rate_diff100);
- if (rate_diff100 <= 3) {
- rate += (rate >> 4);
- if (rate > RATE_THRESHOLD / 1000000)
- rate = RATE_THRESHOLD / 1000000;
- qstats.rate = rate;
- printf(" INC\n");
- } else {
- printf("\n");
- }
- } else {
- /* Need to decrease cgroup rate limit.
- * Currently decreasing by 12.5%, unknown
- * if that is optimal
- */
- printf(" DEC\n");
- rate -= (rate >> 3);
- if (rate < minRate)
- rate = minRate;
- qstats.rate = rate;
- }
- if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY))
- do_error("update map element fails", false);
- }
- } else {
- sleep(dur);
- }
- // Get stats!
- if (stats_flag && bpf_map_lookup_elem(queue_stats_fd, &key, &qstats)) {
- char fname[100];
- FILE *fout;
- if (!outFlag)
- sprintf(fname, "hbm.%d.in", cg_id);
- else
- sprintf(fname, "hbm.%d.out", cg_id);
- fout = fopen(fname, "w");
- fprintf(fout, "id:%d\n", cg_id);
- fprintf(fout, "ERROR: Could not lookup queue_stats\n");
- fclose(fout);
- } else if (stats_flag && qstats.lastPacketTime >
- qstats.firstPacketTime) {
- long long delta_us = (qstats.lastPacketTime -
- qstats.firstPacketTime)/1000;
- unsigned int rate_mbps = ((qstats.bytes_total -
- qstats.bytes_dropped) * 8 /
- delta_us);
- double percent_pkts, percent_bytes;
- char fname[100];
- FILE *fout;
- int k;
- static const char *returnValNames[] = {
- "DROP_PKT",
- "ALLOW_PKT",
- "DROP_PKT_CWR",
- "ALLOW_PKT_CWR"
- };
- #define RET_VAL_COUNT 4
- // Future support of ingress
- // if (!outFlag)
- // sprintf(fname, "hbm.%d.in", cg_id);
- // else
- sprintf(fname, "hbm.%d.out", cg_id);
- fout = fopen(fname, "w");
- fprintf(fout, "id:%d\n", cg_id);
- fprintf(fout, "rate_mbps:%d\n", rate_mbps);
- fprintf(fout, "duration:%.1f secs\n",
- (qstats.lastPacketTime - qstats.firstPacketTime) /
- 1000000000.0);
- fprintf(fout, "packets:%d\n", (int)qstats.pkts_total);
- fprintf(fout, "bytes_MB:%d\n", (int)(qstats.bytes_total /
- 1000000));
- fprintf(fout, "pkts_dropped:%d\n", (int)qstats.pkts_dropped);
- fprintf(fout, "bytes_dropped_MB:%d\n",
- (int)(qstats.bytes_dropped /
- 1000000));
- // Marked Pkts and Bytes
- percent_pkts = (qstats.pkts_marked * 100.0) /
- (qstats.pkts_total + 1);
- percent_bytes = (qstats.bytes_marked * 100.0) /
- (qstats.bytes_total + 1);
- fprintf(fout, "pkts_marked_percent:%6.2f\n", percent_pkts);
- fprintf(fout, "bytes_marked_percent:%6.2f\n", percent_bytes);
- // Dropped Pkts and Bytes
- percent_pkts = (qstats.pkts_dropped * 100.0) /
- (qstats.pkts_total + 1);
- percent_bytes = (qstats.bytes_dropped * 100.0) /
- (qstats.bytes_total + 1);
- fprintf(fout, "pkts_dropped_percent:%6.2f\n", percent_pkts);
- fprintf(fout, "bytes_dropped_percent:%6.2f\n", percent_bytes);
- // ECN CE markings
- percent_pkts = (qstats.pkts_ecn_ce * 100.0) /
- (qstats.pkts_total + 1);
- fprintf(fout, "pkts_ecn_ce:%6.2f (%d)\n", percent_pkts,
- (int)qstats.pkts_ecn_ce);
- // Average cwnd
- fprintf(fout, "avg cwnd:%d\n",
- (int)(qstats.sum_cwnd / (qstats.sum_cwnd_cnt + 1)));
- // Average rtt
- fprintf(fout, "avg rtt:%d\n",
- (int)(qstats.sum_rtt / (qstats.pkts_total + 1)));
- // Average credit
- if (edt_flag)
- fprintf(fout, "avg credit_ms:%.03f\n",
- (qstats.sum_credit /
- (qstats.pkts_total + 1.0)) / 1000000.0);
- else
- fprintf(fout, "avg credit:%d\n",
- (int)(qstats.sum_credit /
- (1500 * ((int)qstats.pkts_total ) + 1)));
- // Return values stats
- for (k = 0; k < RET_VAL_COUNT; k++) {
- percent_pkts = (qstats.returnValCount[k] * 100.0) /
- (qstats.pkts_total + 1);
- fprintf(fout, "%s:%6.2f (%d)\n", returnValNames[k],
- percent_pkts, (int)qstats.returnValCount[k]);
- }
- fclose(fout);
- }
- if (debugFlag)
- read_trace_pipe2();
- goto cleanup;
- err:
- rc = 1;
- cleanup:
- bpf_link__destroy(link);
- bpf_object__close(obj);
- if (cg1 != -1)
- close(cg1);
- if (rc != 0)
- cleanup_cgroup_environment();
- return rc;
- }
- static void Usage(void)
- {
- printf("This program loads a cgroup skb BPF program to enforce\n"
- "cgroup output (egress) bandwidth limits.\n\n"
- "USAGE: hbm [-o] [-d] [-l] [-n <id>] [--no_cn] [-r <rate>]\n"
- " [-s] [-t <secs>] [-w] [-h] [prog]\n"
- " Where:\n"
- " -o indicates egress direction (default)\n"
- " -d print BPF trace debug buffer\n"
- " --edt use fq's Earliest Departure Time\n"
- " -l also limit flows using loopback\n"
- " -n <#> to create cgroup \"/hbm#\" and attach prog\n"
- " Default is /hbm1\n"
- " --no_cn disable CN notifications\n"
- " -r <rate> Rate in Mbps\n"
- " -s Update HBM stats\n"
- " -t <time> Exit after specified seconds (default is 0)\n"
- " -w Work conserving flag. cgroup can increase\n"
- " bandwidth beyond the rate limit specified\n"
- " while there is available bandwidth. Current\n"
- " implementation assumes there is only eth0\n"
- " but can be extended to support multiple NICs\n"
- " -h print this info\n"
- " prog BPF program file name. Name defaults to\n"
- " hbm_out_kern.o\n");
- }
- int main(int argc, char **argv)
- {
- char *prog = "hbm_out_kern.o";
- int k;
- int cg_id = 1;
- char *optstring = "iodln:r:st:wh";
- struct option loptions[] = {
- {"no_cn", 0, NULL, 1},
- {"edt", 0, NULL, 2},
- {NULL, 0, NULL, 0}
- };
- while ((k = getopt_long(argc, argv, optstring, loptions, NULL)) != -1) {
- switch (k) {
- case 1:
- no_cn_flag = true;
- break;
- case 2:
- prog = "hbm_edt_kern.o";
- edt_flag = true;
- break;
- case'o':
- break;
- case 'd':
- debugFlag = true;
- break;
- case 'l':
- loopback_flag = true;
- break;
- case 'n':
- cg_id = atoi(optarg);
- break;
- case 'r':
- minRate = atoi(optarg) * 1.024;
- rate = minRate;
- break;
- case 's':
- stats_flag = true;
- break;
- case 't':
- dur = atoi(optarg);
- break;
- case 'w':
- work_conserving_flag = true;
- break;
- case '?':
- if (optopt == 'n' || optopt == 'r' || optopt == 't')
- fprintf(stderr,
- "Option -%c requires an argument.\n\n",
- optopt);
- case 'h':
- __fallthrough;
- default:
- Usage();
- return 0;
- }
- }
- if (optind < argc)
- prog = argv[optind];
- printf("HBM prog: %s\n", prog != NULL ? prog : "NULL");
- /* Use libbpf 1.0 API mode */
- libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
- return run_bpf_prog(prog, cg_id);
- }
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