test/core/census/trace_context_test.c

/*
 *
 * Copyright 2016, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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#include <grpc/census.h>
#include <grpc/support/log.h>
#include <grpc/support/port_platform.h>
#include <grpc/support/useful.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include "src/core/ext/census/base_resources.h"
#include "src/core/ext/census/resource.h"
#include "test/core/util/test_config.h"

#include "src/core/ext/census/gen/trace_context.pb.h"
#include "src/core/ext/census/trace_context.h"
#include "third_party/nanopb/pb_decode.h"
#include "third_party/nanopb/pb_encode.h"

#define BUF_SIZE 256

/* Encodes a TraceContext structure (ctxt1) to a buffer, and then decodes it
to a second TraceContext (ctxt2).  Validates that the resulting TraceContext
has a span_id, trace_id, and that the values are equal to those in initial
TraceContext. On success, returns true.  If encode_trace_context returns 0,
decode_trace_context fails, or the resulting TraceContext is missing a trace_id
or span_id, it will return false. */
bool validate_encode_decode_context(google_trace_TraceContext *ctxt1,
                                    uint8_t *buffer, size_t buf_size) {
  google_trace_TraceContext ctxt2 = google_trace_TraceContext_init_zero;
  size_t msg_length;
  GPR_ASSERT(ctxt1->has_trace_id && ctxt1->has_span_id);

  msg_length = encode_trace_context(ctxt1, buffer, buf_size);
  if (msg_length == 0) {
    return false;
  }

  if (!decode_trace_context(&ctxt2, buffer, msg_length)) {
    return false;
  }

  if (!ctxt2.has_trace_id || !ctxt2.has_span_id) {
    return false;
  }

  GPR_ASSERT(
      ctxt1->trace_id.hi == ctxt2.trace_id.hi &&
      ctxt1->trace_id.lo == ctxt2.trace_id.lo &&
      ctxt1->span_id == ctxt2.span_id &&
      ctxt1->has_is_sampled == ctxt2.has_is_sampled &&
      (ctxt1->has_is_sampled ? ctxt1->is_sampled == ctxt2.is_sampled : true));

  return true;
}

/* Decodes a proto-encoded TraceContext from a buffer.  If decode_trace_context
fails or the resulting TraceContext is missing a trace_id or span_id it will
return false, otherwise returns true. */
bool validate_decode_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
                             size_t msg_length) {
  // Validate the decoding of a context written to buffer.
  if (!decode_trace_context(ctxt, buffer, msg_length)) {
    return false;
  }

  if (!ctxt->has_trace_id || !ctxt->has_span_id) {
    return false;
  }

  return true;
}

/* Read an encoded trace context from a file.  Validates that the decoding
gives the expected result (succeed). */
static void read_and_validate_context_from_file(google_trace_TraceContext *ctxt,
                                                const char *file,
                                                const bool succeed) {
  uint8_t buffer[BUF_SIZE];
  FILE *input = fopen(file, "rb");
  GPR_ASSERT(input != NULL);
  size_t nbytes = fread(buffer, 1, BUF_SIZE, input);
  GPR_ASSERT(nbytes <= BUF_SIZE && feof(input) && !ferror(input));
  bool res = validate_decode_context(ctxt, buffer, nbytes);
  GPR_ASSERT(res == succeed);
  GPR_ASSERT(fclose(input) == 0);
}

// Test full proto-buffer.
static void test_full() {
  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
  read_and_validate_context_from_file(
      &ctxt, "test/core/census/data/context_full.pb", true);
}

// Test empty proto-buffer.
static void test_empty() {
  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
  read_and_validate_context_from_file(
      &ctxt, "test/core/census/data/context_empty.pb", false);
}

// Test proto-buffer with only trace_id.
static void test_trace_only() {
  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
  read_and_validate_context_from_file(
      &ctxt, "test/core/census/data/context_trace_only.pb", false);
}

// Test proto-buffer with only span_id.
static void test_span_only() {
  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
  read_and_validate_context_from_file(
      &ctxt, "test/core/census/data/context_span_only.pb", false);
}

// Test proto-buffer without is_sampled value.
static void test_no_sample() {
  google_trace_TraceContext ctxt = google_trace_TraceContext_init_zero;
  read_and_validate_context_from_file(
      &ctxt, "test/core/census/data/context_no_sample.pb", true);
  GPR_ASSERT(ctxt.has_is_sampled == false && ctxt.is_sampled == false);
}

static void test_encode_decode() {
  uint8_t buffer[BUF_SIZE] = {0};

  google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
  ctxt1.has_trace_id = true;
  ctxt1.trace_id.has_hi = true;
  ctxt1.trace_id.has_lo = true;
  ctxt1.trace_id.lo = 1;
  ctxt1.trace_id.hi = 2;
  ctxt1.has_span_id = true;
  ctxt1.span_id = 3;
  validate_encode_decode_context(&ctxt1, buffer, sizeof(buffer));

  google_trace_TraceContext ctxt2 = google_trace_TraceContext_init_zero;
  ctxt2.has_trace_id = true;
  ctxt2.trace_id.has_hi = false;
  ctxt2.trace_id.has_lo = false;
  ctxt2.has_span_id = true;
  validate_encode_decode_context(&ctxt2, buffer, sizeof(buffer));
}

// Test a corrupted proto-buffer.
static void test_corrupt() {
  uint8_t buffer[BUF_SIZE] = {0};
  google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
  size_t msg_length;

  ctxt1.has_trace_id = true;
  ctxt1.trace_id.has_hi = true;
  ctxt1.trace_id.has_lo = true;
  ctxt1.trace_id.lo = 1;
  ctxt1.trace_id.hi = 2;
  ctxt1.has_span_id = true;
  ctxt1.span_id = 3;
  ctxt1.is_sampled = true;
  msg_length = encode_trace_context(&ctxt1, buffer, sizeof(buffer));

  /* Corrupt some bytes.  255 (0xFF) should be illegal for the first byte of the
  proto encoded object. */
  buffer[0] = 255;

  bool res = validate_decode_context(&ctxt1, buffer, msg_length);
  GPR_ASSERT(res == false);
}

static void test_buffer_size() {
  // This buffer is too small, so the encode should fail.
  uint8_t buffer[16] = {0};
  google_trace_TraceContext ctxt1 = google_trace_TraceContext_init_zero;
  size_t msg_length;

  ctxt1.has_trace_id = true;
  ctxt1.trace_id.has_hi = true;
  ctxt1.trace_id.has_lo = true;
  ctxt1.trace_id.lo = 1;
  ctxt1.trace_id.hi = 2;
  ctxt1.has_span_id = true;
  ctxt1.span_id = 3;
  ctxt1.is_sampled = true;
  msg_length = encode_trace_context(&ctxt1, buffer, sizeof(buffer));

  GPR_ASSERT(msg_length == 0);
}

int main(int argc, char **argv) {
  grpc_test_init(argc, argv);
  test_full();
  test_empty();
  test_trace_only();
  test_span_only();
  test_encode_decode();
  test_corrupt();
  test_no_sample();
  test_buffer_size();

  fprintf(stderr, "sizeof(void*): %lu\n", sizeof(void *));
  return 0;
}