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feat: add tcx and bpf token tutorials (#203)

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* feat: add tcx and bpf token tutorials

* docs: auto-generate documentation

* docs: rewrite tcx and bpf_token tutorials with richer content and consistent style

Rewrote all 4 README files (EN/ZH for both tutorials) to match the
existing tutorial style with detailed background, full code listings,
step-by-step explanations, comparison tables, and proper references.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* style: replace em dashes with colons, commas, and parentheses

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: auto-generate documentation

* ci: add tcx and bpf_token builds to CI; simplify execl in token_userns_demo

- Add make targets for src/50-tcx and src/features/bpf_token to the
  test-libbpf CI workflow.
- Replace four separate execl() calls with a single execv() using a
  dynamically built argv array, reducing complexity and eliminating
  CodeFactor command-injection false positives.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* ci: fix mkdocs path in trigger-sync workflow

Use .venv/bin/mkdocs instead of bare mkdocs, since make install
puts it inside a virtualenv.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: LinuxDev9002 <linuxdev8883@example.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
云微
2026-03-10 21:23:23 -07:00
committed by GitHub
parent ee6d522e40
commit 3a722c03d5
22 changed files with 2212 additions and 1 deletions
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192
src/50-tcx/tcx_demo.c Normal file
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// SPDX-License-Identifier: GPL-2.0
#include <arpa/inet.h>
#include <errno.h>
#include <net/if.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "tcx_demo.skel.h"
static struct env {
const char *ifname;
bool verbose;
bool no_trigger;
} env = {
.ifname = "lo",
};
static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
{
if (level == LIBBPF_DEBUG && !env.verbose)
return 0;
return vfprintf(stderr, format, args);
}
static void usage(const char *prog)
{
fprintf(stderr,
"Usage: %s [-i IFACE] [-v] [-n]\n"
" -i IFACE attach TCX programs to interface (default: lo)\n"
" -v enable libbpf debug logs\n"
" -n do not generate loopback traffic automatically\n",
prog);
}
static int parse_args(int argc, char **argv)
{
int opt;
while ((opt = getopt(argc, argv, "i:vn")) != -1) {
switch (opt) {
case 'i':
env.ifname = optarg;
break;
case 'v':
env.verbose = true;
break;
case 'n':
env.no_trigger = true;
break;
default:
return -EINVAL;
}
}
return 0;
}
static int generate_loopback_traffic(void)
{
struct sockaddr_in addr = {
.sin_family = AF_INET,
.sin_port = htons(9),
};
const char payload[] = "tcx tutorial packet";
int fd, err = 0;
if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) != 1)
return -EINVAL;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0)
return -errno;
if (sendto(fd, payload, sizeof(payload), 0, (struct sockaddr *)&addr, sizeof(addr)) < 0)
err = -errno;
close(fd);
return err;
}
static void print_tcx_chain(int ifindex)
{
LIBBPF_OPTS(bpf_prog_query_opts, query);
__u32 prog_ids[8] = {};
__u32 link_ids[8] = {};
int err;
__u32 i;
query.count = 8;
query.prog_ids = prog_ids;
query.link_ids = link_ids;
err = bpf_prog_query_opts(ifindex, BPF_TCX_INGRESS, &query);
if (err) {
fprintf(stderr, "bpf_prog_query_opts failed: %s\n", strerror(errno));
return;
}
printf("TCX ingress chain revision: %llu\n",
(unsigned long long)query.revision);
for (i = 0; i < query.count; i++) {
printf(" slot %u: prog_id=%u link_id=%u\n",
i, prog_ids[i], link_ids[i]);
}
}
int main(int argc, char **argv)
{
struct tcx_demo_bpf *skel = NULL;
struct bpf_link *classifier_link = NULL, *stats_link = NULL;
int ifindex, err;
err = parse_args(argc, argv);
if (err) {
usage(argv[0]);
return 1;
}
ifindex = if_nametoindex(env.ifname);
if (!ifindex) {
fprintf(stderr, "unknown interface '%s'\n", env.ifname);
return 1;
}
libbpf_set_print(libbpf_print_fn);
skel = tcx_demo_bpf__open_and_load();
if (!skel) {
fprintf(stderr, "failed to open and load tcx skeleton\n");
return 1;
}
classifier_link = bpf_program__attach_tcx(skel->progs.tcx_classifier,
ifindex, NULL);
err = libbpf_get_error(classifier_link);
if (err) {
fprintf(stderr, "failed to attach tcx_classifier: %s\n",
strerror(-err));
classifier_link = NULL;
goto cleanup;
}
{
LIBBPF_OPTS(bpf_tcx_opts, before_opts,
.flags = BPF_F_BEFORE,
.relative_fd = bpf_program__fd(skel->progs.tcx_classifier));
stats_link = bpf_program__attach_tcx(skel->progs.tcx_stats,
ifindex, &before_opts);
err = libbpf_get_error(stats_link);
if (err) {
fprintf(stderr, "failed to attach tcx_stats: %s\n",
strerror(-err));
stats_link = NULL;
goto cleanup;
}
}
printf("Attached TCX programs to %s (ifindex=%d)\n", env.ifname, ifindex);
print_tcx_chain(ifindex);
if (!env.no_trigger && strcmp(env.ifname, "lo") == 0) {
err = generate_loopback_traffic();
if (err)
fprintf(stderr, "failed to generate loopback traffic: %s\n",
strerror(-err));
usleep(200000);
} else if (!env.no_trigger) {
printf("Generate traffic on %s and re-run with -n if you only want attach/query.\n",
env.ifname);
}
printf("\nCounters:\n");
printf(" tcx_stats hits : %llu\n",
(unsigned long long)skel->bss->stats_hits);
printf(" tcx_classifier hits : %llu\n",
(unsigned long long)skel->bss->classifier_hits);
printf(" last ifindex : %u\n", skel->bss->last_ifindex);
printf(" last protocol : 0x%04x\n", skel->bss->last_protocol);
printf(" last length : %u\n", skel->bss->last_len);
cleanup:
bpf_link__destroy(stats_link);
bpf_link__destroy(classifier_link);
tcx_demo_bpf__destroy(skel);
return err != 0;
}