Lightning/Sources/HTTP/Parser.swift

442 lines
13 KiB
Swift

// Parser.swift
//
// The MIT License (MIT)
//
// Copyright (c) 2016 Edge
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
import CHTTPParser
import Foundation
typealias CParserPointer = UnsafeMutablePointer<http_parser>
typealias RawParserPointer = UnsafeMutablePointer<RawParser>
private func bridge<T: AnyObject>(_ obj: T) -> UnsafeMutableRawPointer {
return Unmanaged.passUnretained(obj).toOpaque()
}
private func bridge<T: AnyObject>(_ ptr: UnsafeMutableRawPointer) -> T {
return Unmanaged<T>.fromOpaque(ptr).takeUnretainedValue()
}
struct ParseError: Error {
let description: String
}
public class RequestParser {
private let parser: FullMessageParser!
var onRequest: ((Request) -> Void)?
init(onRequest: ((Request) -> Void)? = nil) {
self.onRequest = onRequest
self.parser = FullMessageParser(type: HTTP_REQUEST)
self.parser.onComplete = { [weak self] parseState in
guard let uri = URL(string: parseState.uri) else {
throw ParseError(description: "URL not valid.")
}
let request = Request(
method: Method(code: parseState.method),
uri: uri,
version: Version(major: parseState.version.major, minor: parseState.version.minor),
rawHeaders: parseState.rawHeaders,
body: parseState.body
)
self?.onRequest?(request)
}
}
public func parse(_ data: Data) throws {
try parser.parse(data)
}
}
public class ResponseParser {
private let parser: FullMessageParser
var onResponse: ((Response) -> Void)?
init(onResponse: ((Response) -> Void)? = nil) {
self.onResponse = onResponse
self.parser = FullMessageParser(type: HTTP_RESPONSE)
self.parser.onComplete = { [weak self] parseState in
let response = Response(
version: Version(major: parseState.version.major, minor: parseState.version.minor),
status: Status(code: parseState.statusCode),
rawHeaders: parseState.rawHeaders,
body: parseState.body
)
self?.onResponse?(response)
}
}
public func parse(_ data: Data) throws {
try parser.parse(data)
}
}
private final class FullMessageParser {
struct ParseState {
var version: (major: Int, minor: Int) = (0, 0)
var rawHeaders: [String] = []
var body: Data = Data()
// Response
var statusCode: Int! = nil
var statusPhrase = ""
// Request
var method: Int! = nil
var uri = ""
}
var state = ParseState()
var onComplete: ((ParseState) throws -> ())?
let rawParser: RawParser
init(type: http_parser_type, onComplete: ((ParseState) throws -> ())? = nil) {
self.onComplete = onComplete
self.rawParser = RawParser(type: type)
self.rawParser.delegate = self
}
func parse(_ data: Data) throws {
try rawParser.parse(data)
}
}
extension FullMessageParser: RawParserDelegate {
func onMessageBegin() throws {
// No state change
}
func onURL(data: UnsafeBufferPointer<UInt8>) throws {
guard let uri = String(bytes: data, encoding: .utf8) else {
throw ParseError(description: "URI could not be encoded as UTF8.")
}
state.uri += uri
}
func onStatus(data: UnsafeBufferPointer<UInt8>) throws {
guard let partialStatusPhrase = String(bytes: data, encoding: .utf8) else {
throw ParseError(description: "Status phrase could not be encoded as UTF8.")
}
state.statusPhrase += partialStatusPhrase
}
func onHeaderField(data: UnsafeBufferPointer<UInt8>) throws {
guard let partialHeaderField = String(bytes: data, encoding: .utf8) else {
throw ParseError(description: "Header field could not be encoded as UTF8.")
}
if state.rawHeaders.count % 2 == 0 {
state.rawHeaders.append("")
}
state.rawHeaders[state.rawHeaders.count - 1] += partialHeaderField
}
func onHeaderValue(data: UnsafeBufferPointer<UInt8>) throws {
guard let partialHeaderValue = String(bytes: data, encoding: .utf8) else {
throw ParseError(description: "Header value could not be encoded as UTF8.")
}
if state.rawHeaders.count % 2 == 1 {
state.rawHeaders.append("")
}
state.rawHeaders[state.rawHeaders.count - 1] += partialHeaderValue
}
func onHeadersComplete(
method: Int,
statusCode: Int,
majorVersion: Int,
minorVersion: Int
) throws -> HeadersCompleteDirective {
state.statusCode = statusCode
state.version = (major: majorVersion, minor: minorVersion)
state.method = method
return .none
}
func onBody(data: UnsafeBufferPointer<UInt8>) throws {
state.body += Array(data)
}
func onMessageComplete() throws {
try onComplete?(state)
// Reset state
state = ParseState()
}
func onChunkHeader() throws {
// No state change
}
func onChunkComplete() throws {
// No state change
}
}
public enum HeadersCompleteDirective {
case none
case noBody
case noBodyNoFurtherResponses
}
public protocol RawParserDelegate: class {
func onMessageBegin() throws
func onMessageComplete() throws
func onURL(data: UnsafeBufferPointer<UInt8>) throws
func onStatus(data: UnsafeBufferPointer<UInt8>) throws
func onHeaderField(data: UnsafeBufferPointer<UInt8>) throws
func onHeaderValue(data: UnsafeBufferPointer<UInt8>) throws
func onHeadersComplete(
method: Int,
statusCode: Int,
majorVersion: Int,
minorVersion: Int
) throws -> HeadersCompleteDirective
func onBody(data: UnsafeBufferPointer<UInt8>) throws
func onChunkHeader() throws
func onChunkComplete() throws
}
public final class RawParser {
// Sneaky sneaky, I'm a meanie.
// Here I create a constant private pointer to our "constant" http_parser
// The can be therefore mutated through the pointer, but only within the RawParser.
let parser = http_parser()
private let parserPointer: UnsafeMutablePointer<http_parser>
var type: http_parser_type
fileprivate weak var delegate: RawParserDelegate?
public init(type: http_parser_type, delegate: RawParserDelegate? = nil) {
self.type = type
self.delegate = delegate
parserPointer = withUnsafeMutablePointer(to: &parser) { $0 }
reset()
}
func reset() {
http_parser_init(parserPointer, self.type)
// Set self as the context. self must be a reference type.
parserPointer.pointee.data = bridge(self)
}
public func parse(_ data: Data) throws {
try data.withUnsafeBytes { (convertedPointer: UnsafePointer<Int8>) in
let bytesParsed = http_parser_execute(
parserPointer,
&requestSettings,
convertedPointer,
data.count
)
guard bytesParsed == data.count else {
reset()
let errorName = http_errno_name(http_errno(parser.http_errno))!
let errorDescription = http_errno_description(http_errno(parser.http_errno))!
let error = ParseError(
description: "\(String(validatingUTF8: errorName)!):" +
" \(String(validatingUTF8: errorDescription)!)"
)
throw error
}
}
}
}
var requestSettings: http_parser_settings = {
var settings = http_parser_settings()
http_parser_settings_init(&settings)
settings.on_message_begin = onMessageBegin
settings.on_url = onURL
settings.on_status = onStatus
settings.on_header_field = onHeaderField
settings.on_header_value = onHeaderValue
settings.on_headers_complete = onHeadersComplete
settings.on_body = onBody
settings.on_message_complete = onMessageComplete
settings.on_chunk_header = onChunkHeader
settings.on_chunk_complete = onChunkComplete
return settings
}()
// MARK: C function pointer spring boards
private func onMessageBegin(_ parser: CParserPointer?) -> Int32 {
let rawParser: RawParser = bridge(parser!.pointee.data)
do {
try rawParser.delegate?.onMessageBegin()
} catch {
return 1
}
return 0
}
private func onURL(_ parser: CParserPointer?, data: UnsafePointer<Int8>?, length: Int) -> Int32 {
let rawParser: RawParser = bridge(parser!.pointee.data)
do {
try data?.withMemoryRebound(to: UInt8.self, capacity: length) { convertedPointer in
try rawParser
.delegate?
.onURL(data: UnsafeBufferPointer(start: convertedPointer, count: length))
}
} catch {
return 1
}
return 0
}
private func onStatus(_ parser: CParserPointer?, data: UnsafePointer<Int8>?, length: Int) -> Int32 {
let rawParser: RawParser = bridge(parser!.pointee.data)
do {
try data?.withMemoryRebound(to: UInt8.self, capacity: length) { convertedPointer in
try rawParser
.delegate?
.onStatus(data: UnsafeBufferPointer(start: convertedPointer, count: length))
}
} catch {
return 1
}
return 0
}
private func onHeaderField(
_ parser: CParserPointer?,
data: UnsafePointer<Int8>?,
length: Int
) -> Int32 {
let rawParser: RawParser = bridge(parser!.pointee.data)
do {
try data?.withMemoryRebound(to: UInt8.self, capacity: length) { convertedPointer in
try rawParser
.delegate?
.onHeaderField(data: UnsafeBufferPointer(start: convertedPointer, count: length))
}
} catch {
return 1
}
return 0
}
private func onHeaderValue(
_ parser: CParserPointer?,
data: UnsafePointer<Int8>?,
length: Int
) -> Int32 {
let rawParser: RawParser = bridge(parser!.pointee.data)
do {
try data?.withMemoryRebound(to: UInt8.self, capacity: length) { convertedPointer in
try rawParser
.delegate?
.onHeaderValue(data: UnsafeBufferPointer(start: convertedPointer, count: length))
}
} catch {
return 1
}
return 0
}
private func onHeadersComplete(_ cParserPointer: CParserPointer?) -> Int32 {
let rawParser: RawParser = bridge(cParserPointer!.pointee.data)
let method = Int(rawParser.parser.method)
let statusCode = Int(rawParser.parser.status_code)
let majorVersion = Int(rawParser.parser.http_major)
let minorVersion = Int(rawParser.parser.http_minor)
do {
let directive = try rawParser.delegate?.onHeadersComplete(
method: method,
statusCode: statusCode,
majorVersion: majorVersion,
minorVersion: minorVersion
)
switch directive {
case .none: return 0
case .none?: return 0
case .noBody?: return 1
case .noBodyNoFurtherResponses?: return 2
}
} catch {
return 3 // on_headers_complete is a special snowflake
}
}
private func onBody(_ cParserPointer: CParserPointer?, data: UnsafePointer<Int8>?, length: Int) -> Int32 {
let rawParser: RawParser = bridge(cParserPointer!.pointee.data)
do {
try data?.withMemoryRebound(to: UInt8.self, capacity: length) { convertedPointer in
try rawParser
.delegate?
.onBody(data:UnsafeBufferPointer(start: convertedPointer, count: length))
}
} catch {
return 1
}
return 0
}
private func onMessageComplete(_ cParserPointer: CParserPointer?) -> Int32 {
let rawParser: RawParser = bridge(cParserPointer!.pointee.data)
do {
try rawParser.delegate?.onMessageComplete()
} catch {
return 1
}
return 0
}
private func onChunkHeader(_ cParserPointer: CParserPointer?) -> Int32 {
let rawParser: RawParser = bridge(cParserPointer!.pointee.data)
do {
try rawParser.delegate?.onChunkHeader()
} catch {
return 1
}
return 0
}
private func onChunkComplete(_ cParserPointer: CParserPointer?) -> Int32 {
let rawParser: RawParser = bridge(cParserPointer!.pointee.data)
do {
try rawParser.delegate?.onChunkComplete()
} catch {
return 1
}
return 0
}