Quelle  ringbuf_multi.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <test_progs.h>
#include <sys/epoll.h>
#include "test_ringbuf_multi.skel.h"

static int duration = 0;

struct sample {
 int pid;
 int seq;
 long value;
 char comm[16];
};

static int process_sample(void *ctx, void *data, size_t len)
{
 int ring = (unsigned long)ctx;
 struct sample *s = data;

 switch (s->seq) {
 case 0:
  CHECK(ring != 1, "sample1_ring", "exp %d, got %d\n", 1, ring);
  CHECK(s->value != 333, "sample1_value", "exp %ld, got %ld\n",
        333L, s->value);
  break;
 case 1:
  CHECK(ring != 2, "sample2_ring", "exp %d, got %d\n", 2, ring);
  CHECK(s->value != 777, "sample2_value", "exp %ld, got %ld\n",
        777L, s->value);
  break;
 default:
  CHECK(true, "extra_sample", "unexpected sample seq %d, val %ld\n",
        s->seq, s->value);
  return -1;
 }

 return 0;
}

void test_ringbuf_multi(void)
{
 struct test_ringbuf_multi *skel;
 struct ring_buffer *ringbuf = NULL;
 struct ring *ring_old;
 struct ring *ring;
 int err;
 int page_size = getpagesize();
 int proto_fd = -1;

 skel = test_ringbuf_multi__open();
 if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
  return;

 /* validate ringbuf size adjustment logic */
 ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_before");
 ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size + 1), "rb1_resize");
 ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), 2 * page_size, "rb1_size_after");
 ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size), "rb1_reset");
 ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_final");

 proto_fd = bpf_map_create(BPF_MAP_TYPE_RINGBUF, NULL, 0, 0, page_size, NULL);
 if (CHECK(proto_fd < 0, "bpf_map_create", "bpf_map_create failed\n"))
  goto cleanup;

 err = bpf_map__set_inner_map_fd(skel->maps.ringbuf_hash, proto_fd);
 if (CHECK(err != 0, "bpf_map__set_inner_map_fd", "bpf_map__set_inner_map_fd failed\n"))
  goto cleanup;

 err = test_ringbuf_multi__load(skel);
 if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
  goto cleanup;

 close(proto_fd);
 proto_fd = -1;

 /* make sure we can't resize ringbuf after object load */
 if (!ASSERT_ERR(bpf_map__set_max_entries(skel->maps.ringbuf1, 3 * page_size), "rb1_resize_after_load"))
  goto cleanup;

 /* only trigger BPF program for current process */
 skel->bss->pid = getpid();

 ringbuf = ring_buffer__new(bpf_map__fd(skel->maps.ringbuf1),
       process_sample, (void *)(long)1, NULL);
 if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n"))
  goto cleanup;

 /* verify ring_buffer__ring returns expected results */
 ring = ring_buffer__ring(ringbuf, 0);
 if (!ASSERT_OK_PTR(ring, "ring_buffer__ring_idx_0"))
  goto cleanup;
 ring_old = ring;
 ring = ring_buffer__ring(ringbuf, 1);
 ASSERT_ERR_PTR(ring, "ring_buffer__ring_idx_1");

 err = ring_buffer__add(ringbuf, bpf_map__fd(skel->maps.ringbuf2),
         process_sample, (void *)(long)2);
 if (CHECK(err, "ringbuf_add", "failed to add another ring\n"))
  goto cleanup;

 /* verify adding a new ring didn't invalidate our older pointer */
 ring = ring_buffer__ring(ringbuf, 0);
 if (!ASSERT_EQ(ring, ring_old, "ring_buffer__ring_again"))
  goto cleanup;

 err = test_ringbuf_multi__attach(skel);
 if (CHECK(err, "skel_attach", "skeleton attachment failed: %d\n", err))
  goto cleanup;

 /* trigger few samples, some will be skipped */
 skel->bss->target_ring = 0;
 skel->bss->value = 333;
 syscall(__NR_getpgid);

 /* skipped, no ringbuf in slot 1 */
 skel->bss->target_ring = 1;
 skel->bss->value = 555;
 syscall(__NR_getpgid);

 skel->bss->target_ring = 2;
 skel->bss->value = 777;
 syscall(__NR_getpgid);

 /* poll for samples, should get 2 ringbufs back */
 err = ring_buffer__poll(ringbuf, -1);
 if (CHECK(err != 2, "poll_res", "expected 2 records, got %d\n", err))
  goto cleanup;

 /* expect extra polling to return nothing */
 err = ring_buffer__poll(ringbuf, 0);
 if (CHECK(err < 0, "extra_samples", "poll result: %d\n", err))
  goto cleanup;

 CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n",
       0L, skel->bss->dropped);
 CHECK(skel->bss->skipped != 1, "err_skipped", "exp %ld, got %ld\n",
       1L, skel->bss->skipped);
 CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n",
       2L, skel->bss->total);

cleanup:
 if (proto_fd >= 0)
  close(proto_fd);
 ring_buffer__free(ringbuf);
 test_ringbuf_multi__destroy(skel);
}