network_traffic_annotation.h | Explore in Territory

// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40284755): Remove this and spanify to fix the errors.
#pragma allow_unsafe_buffers
#endif

#ifndef NET_TRAFFIC_ANNOTATION_NETWORK_TRAFFIC_ANNOTATION_H_
#define NET_TRAFFIC_ANNOTATION_NETWORK_TRAFFIC_ANNOTATION_H_

#include <cstdint>

#include "base/check.h"
#include "base/notreached.h"
#include "build/build_config.h"
#include "build/chromeos_buildflags.h"

#if BUILDFLAG(IS_ANDROID)
#include "base/android/scoped_java_ref.h"
#endif

namespace {

// Recursively compute hash code of the given string as a constant expression.
template <int N>
constexpr uint32_t recursive_hash(const char* str) { … }

// Recursion stopper for the above function. Note that string of size 0 will
// result in compile error.
template <>
constexpr uint32_t recursive_hash<1>(const char* str) { … }

// Entry point to function that computes hash as constant expression.
#define COMPUTE_NETWORK_TRAFFIC_ANNOTATION_ID_HASH(S) …

constexpr int TRAFFIC_ANNOTATION_UNINITIALIZED = …;

}  // namespace

namespace net {

struct PartialNetworkTrafficAnnotationTag;

// Defined types for network traffic annotation tags.
struct NetworkTrafficAnnotationTag { … };

struct PartialNetworkTrafficAnnotationTag { … };

// Function to convert a network traffic annotation's unique id and protobuf
// text into a NetworkTrafficAnnotationTag.
//
// This function serves as a tag that can be discovered and extracted via
// clang tools. This allows reviewing all network traffic that is generated
// and annotated by Chrome.
//
// |unique_id| should be a string that uniquely identifies this annotation
// across all of Chromium source code. |unique_id| should be kept unchanged
// as long as possible as its hashed value will be used for differnt logging,
// debugging, or auditing tasks. Unique ids should include only alphanumeric
// characters and underline.
// |proto| is a text-encoded NetworkTrafficAnnotation protobuf (see
// chrome/browser/privacy/traffic_annotation.proto)
//
// An empty and a sample template for the text-encoded protobuf can be found in
// tools/traffic_annotation/sample_traffic_annotation.cc.
// TODO(crbug.com/40505662): Add tools to check annotation text's format during
// presubmit checks.
template <size_t N1, size_t N2>
constexpr NetworkTrafficAnnotationTag DefineNetworkTrafficAnnotation(
    const char (&unique_id)[N1],
    const char (&proto)[N2]) { … }

// There are cases where the network traffic annotation cannot be fully
// specified in one place. For example, in one place we know the trigger of a
// network request and in another place we know the data that will be sent. In
// these cases, we prefer that both parts of the annotation appear in context so
// that they are updated if code changes. The following functions help splitting
// the network traffic annotation into two pieces. Please refer to
// tools/traffic_annotation/sample_traffic_annotation.cc for usage samples.

// This function can be used to define a partial annotation that will be
// completed later. The completing annotation can be defined with either of
// 'CompleteNetworkTrafficAnnotation' or
// 'BranchedCompleteNetworkTrafficAnnotation' functions. In case of
// CompleteNetworkTrafficAnnotation, |completing_id| is the unique id of the
// annotation that will complete it. In the case of
// BranchedCompleteNetworkTrafficAnnotation, |completing_id| is the group id
// of the completing annotations.
template <size_t N1, size_t N2, size_t N3>
constexpr PartialNetworkTrafficAnnotationTag
DefinePartialNetworkTrafficAnnotation(const char (&unique_id)[N1],
                                      const char (&completing_id)[N2],
                                      const char (&proto)[N3]) { … }

// This function can be used to define a completing partial annotation. This
// annotation adds details to another annotation that is defined before.
// |partial_annotation| is the PartialNetworkTrafficAnnotationTag returned
// by a call to DefinePartialNetworkTrafficAnnotation().
template <size_t N1, size_t N2>
NetworkTrafficAnnotationTag CompleteNetworkTrafficAnnotation(
    const char (&unique_id)[N1],
    const PartialNetworkTrafficAnnotationTag& partial_annotation,
    const char (&proto)[N2]) { … }

// This function can be used to define a completing partial annotation that is
// branched into several annotations. In this case, |group_id| is a common id
// that is used by all members of the branch and referenced by partial
// annotation that is completed by them.
template <size_t N1, size_t N2, size_t N3>
NetworkTrafficAnnotationTag BranchedCompleteNetworkTrafficAnnotation(
    const char (&unique_id)[N1],
    const char (&group_id)[N2],
    const PartialNetworkTrafficAnnotationTag& partial_annotation,
    const char (&proto)[N3]) { … }

// Example for joining N x 1 partial annotations:
// N functions foo1(), ..., fooN() call one function bar(). Each
// foo...() function defines part of a network traffic annotation.
// These N partial annotations are combined with a second part in
// bar().
//
// void foo1() {
//   auto tag = DefinePartialNetworkTrafficAnnotation(
//       "call_by_foo1", "completion_by_bar", [partial_proto]);
//   bar(tag);
// }
// void foo2() {
//   auto tag = DefinePartialNetworkTrafficAnnotation(
//       "call_by_foo2", "completion_by_bar", [partial_proto]);
//   bar(tag);
// }
// void bar(PartialNetworkTrafficAnnotationTag tag) {
//   auto final_tag = CompleteNetworkTrafficAnnotation(
//     "completion_by_bar", tag, [rest_of_proto]);
//   // final_tag matches the value of tag (which is hash code of
//   // "call_by_fooX" where X can be 1 or 2).
//   net::URLFetcher::Create(..., final_tag);
// }

// Example for joining 1 x N partial annotations:
// A function foo() calls a function bar(bool param), that sends
// different network requests depending on param. Both functions
// define parts of the network traffic annotation.
//
// void foo(bool param) {
//   auto tag = DefinePartialNetworkTrafficAnnotation(
//       "call_by_foo1", "completion_by_bar", [partial_proto]);
//   bar(param, tag);
// }
// void bar(bool param, PartialNetworkTrafficAnnotationTag tag) {
//   if (param) {
//     auto final_tag = BranchedCompleteNetworkTrafficAnnotation(
//       "call_bool_branch_1", "completion_by_bar", tag, [rest_of_proto]);
//     // final_tag is hash code of "call_bool_branch_1".
//     net::URLFetcher::Create(url1, ..., final_tag);
//   } else {
//     auto final_tag = BranchedCompleteNetworkTrafficAnnotation(
//       "call_bool_branch_2", "completion_by_bar", tag, [rest_of_proto]);
//     // final_tag is hash code of "call_bool_branch_2".
//     net::URLFetcher::Create(url2, ..., final_tag);
//   }
// }

// Please do not use this unless uninitialized annotations are required.
// Mojo interfaces for this class and the next one are defined in
// '/services/network/public/mojom'.
struct MutableNetworkTrafficAnnotationTag { … };

inline MutableNetworkTrafficAnnotationTag
CreateMutableNetworkTrafficAnnotationTag(int32_t unique_id_hash_code) { … }

struct MutablePartialNetworkTrafficAnnotationTag { … };

}  // namespace net

// Placeholder for unannotated usages.
#if !BUILDFLAG(IS_WIN) && !BUILDFLAG(IS_LINUX) && !BUILDFLAG(IS_CHROMEOS)
#define TRAFFIC_ANNOTATION_WITHOUT_PROTO …
#endif

// These annotations are unavailable on desktop Linux + Windows. They are
// available on other platforms, since we only audit network annotations on
// Linux & Windows.
//
// On Linux and Windows, use MISSING_TRAFFIC_ANNOTATION or
// TRAFFIC_ANNOTATION_FOR_TESTS.
// TODO(crbug.com/40118868): Revisit once build flag switch of lacros-chrome is
// complete.
#if !BUILDFLAG(IS_WIN) && \
    !(BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS_LACROS))

#define NO_TRAFFIC_ANNOTATION_YET …

#endif

#define MISSING_TRAFFIC_ANNOTATION …

#endif  // NET_TRAFFIC_ANNOTATION_NETWORK_TRAFFIC_ANNOTATION_H_
chromium/net/traffic_annotation/network_traffic_annotation.h
