1//===-- llvm/Debuginfod/HTTPServer.cpp - HTTP server library -----*- C++-*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10///
11/// This file defines the methods of the HTTPServer class and the streamFile
12/// function.
13///
14//===----------------------------------------------------------------------===//
15
16#include "llvm/Debuginfod/HTTPServer.h"
17#include "llvm/ADT/StringExtras.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/Support/Errc.h"
20#include "llvm/Support/Error.h"
21#include "llvm/Support/FileSystem.h"
22#include "llvm/Support/MemoryBuffer.h"
23#include "llvm/Support/Regex.h"
24
25#ifdef LLVM_ENABLE_HTTPLIB
26#include "httplib.h"
27#endif
28
29using namespace llvm;
30
31char HTTPServerError::ID = 0;
32
33HTTPServerError::HTTPServerError(const Twine &Msg) : Msg(Msg.str()) {}
34
35void HTTPServerError::log(raw_ostream &OS) const { OS << Msg; }
36
37bool llvm::streamFile(HTTPServerRequest &Request, StringRef FilePath) {
38 Expected<sys::fs::file_t> FDOrErr = sys::fs::openNativeFileForRead(Name: FilePath);
39 if (Error Err = FDOrErr.takeError()) {
40 consumeError(Err: std::move(Err));
41 Request.setResponse({.Code: 404u, .ContentType: "text/plain", .Body: "Could not open file to read.\n"});
42 return false;
43 }
44 ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
45 MemoryBuffer::getOpenFile(FD: *FDOrErr, Filename: FilePath,
46 /*FileSize=*/-1,
47 /*RequiresNullTerminator=*/false);
48 sys::fs::closeFile(F&: *FDOrErr);
49 if (Error Err = errorCodeToError(EC: MBOrErr.getError())) {
50 consumeError(Err: std::move(Err));
51 Request.setResponse({.Code: 404u, .ContentType: "text/plain", .Body: "Could not memory-map file.\n"});
52 return false;
53 }
54 // Lambdas are copied on conversion to std::function, preventing use of
55 // smart pointers.
56 MemoryBuffer *MB = MBOrErr->release();
57 Request.setResponse({.Code: 200u, .ContentType: "application/octet-stream", .ContentLength: MB->getBufferSize(),
58 .Provider: [=](size_t Offset, size_t Length) -> StringRef {
59 return MB->getBuffer().substr(Start: Offset, N: Length);
60 },
61 .CompletionHandler: [=](bool Success) { delete MB; }});
62 return true;
63}
64
65#ifdef LLVM_ENABLE_HTTPLIB
66
67bool HTTPServer::isAvailable() { return true; }
68
69HTTPServer::HTTPServer() { Server = std::make_unique<httplib::Server>(); }
70
71HTTPServer::~HTTPServer() { stop(); }
72
73static void expandUrlPathMatches(const std::smatch &Matches,
74 HTTPServerRequest &Request) {
75 bool UrlPathSet = false;
76 for (const auto &it : Matches) {
77 if (UrlPathSet)
78 Request.UrlPathMatches.push_back(it);
79 else {
80 Request.UrlPath = it;
81 UrlPathSet = true;
82 }
83 }
84}
85
86HTTPServerRequest::HTTPServerRequest(const httplib::Request &HTTPLibRequest,
87 httplib::Response &HTTPLibResponse)
88 : HTTPLibResponse(HTTPLibResponse) {
89 expandUrlPathMatches(HTTPLibRequest.matches, *this);
90}
91
92void HTTPServerRequest::setResponse(HTTPResponse Response) {
93 HTTPLibResponse.set_content(Response.Body.begin(), Response.Body.size(),
94 Response.ContentType);
95 HTTPLibResponse.status = Response.Code;
96}
97
98void HTTPServerRequest::setResponse(StreamingHTTPResponse Response) {
99 HTTPLibResponse.set_content_provider(
100 Response.ContentLength, Response.ContentType,
101 [=](size_t Offset, size_t Length, httplib::DataSink &Sink) {
102 if (Offset < Response.ContentLength) {
103 StringRef Chunk = Response.Provider(Offset, Length);
104 Sink.write(Chunk.begin(), Chunk.size());
105 }
106 return true;
107 },
108 [=](bool Success) { Response.CompletionHandler(Success); });
109
110 HTTPLibResponse.status = Response.Code;
111}
112
113Error HTTPServer::get(StringRef UrlPathPattern, HTTPRequestHandler Handler) {
114 std::string ErrorMessage;
115 if (!Regex(UrlPathPattern).isValid(ErrorMessage))
116 return createStringError(errc::argument_out_of_domain, ErrorMessage);
117 Server->Get(std::string(UrlPathPattern),
118 [Handler](const httplib::Request &HTTPLibRequest,
119 httplib::Response &HTTPLibResponse) {
120 HTTPServerRequest Request(HTTPLibRequest, HTTPLibResponse);
121 Handler(Request);
122 });
123 return Error::success();
124}
125
126Error HTTPServer::bind(unsigned ListenPort, const char *HostInterface) {
127 if (!Server->bind_to_port(HostInterface, ListenPort))
128 return createStringError(errc::io_error,
129 "Could not assign requested address.");
130 Port = ListenPort;
131 return Error::success();
132}
133
134Expected<unsigned> HTTPServer::bind(const char *HostInterface) {
135 int ListenPort = Server->bind_to_any_port(HostInterface);
136 if (ListenPort < 0)
137 return createStringError(errc::io_error,
138 "Could not assign any port on requested address.");
139 return Port = ListenPort;
140}
141
142Error HTTPServer::listen() {
143 if (!Port)
144 return createStringError(errc::io_error,
145 "Cannot listen without first binding to a port.");
146 if (!Server->listen_after_bind())
147 return createStringError(
148 errc::io_error,
149 "An unknown error occurred when cpp-httplib attempted to listen.");
150 return Error::success();
151}
152
153void HTTPServer::stop() {
154 Server->stop();
155 Port = 0;
156}
157
158#else
159
160// TODO: Implement barebones standalone HTTP server implementation.
161bool HTTPServer::isAvailable() { return false; }
162
163HTTPServer::HTTPServer() = default;
164
165HTTPServer::~HTTPServer() = default;
166
167void HTTPServerRequest::setResponse(HTTPResponse Response) {
168 llvm_unreachable("no httplib");
169}
170
171void HTTPServerRequest::setResponse(StreamingHTTPResponse Response) {
172 llvm_unreachable("no httplib");
173}
174
175Error HTTPServer::get(StringRef UrlPathPattern, HTTPRequestHandler Handler) {
176 // TODO(https://github.com/llvm/llvm-project/issues/63873) We would ideally
177 // return an error as well but that's going to require refactoring of error
178 // handling in DebuginfodServer.
179 return Error::success();
180}
181
182Error HTTPServer::bind(unsigned ListenPort, const char *HostInterface) {
183 return make_error<HTTPServerError>(Args: "no httplib");
184}
185
186Expected<unsigned> HTTPServer::bind(const char *HostInterface) {
187 return make_error<HTTPServerError>(Args: "no httplib");
188}
189
190Error HTTPServer::listen() {
191 return make_error<HTTPServerError>(Args: "no httplib");
192}
193
194void HTTPServer::stop() {
195 llvm_unreachable("no httplib");
196}
197
198#endif // LLVM_ENABLE_HTTPLIB
199