Fork of the espurna firmware for `mhsw` switches
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/*
API & WEB API MODULE
Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
Copyright (C) 2020-2021 by Maxim Prokhorov <prokhorov dot max at outlook dot com>
*/
#include "api.h"
// -----------------------------------------------------------------------------
#include "system.h"
#include "rpc.h"
#if WEB_SUPPORT
#include "web.h"
#include <ESPAsyncTCP.h>
#include <ArduinoJson.h>
#endif
#include <algorithm>
#include <memory>
#include <cstring>
#include <forward_list>
#include <vector>
// -----------------------------------------------------------------------------
PathParts::PathParts(const String& path) :
_path(path)
{
if (!_path.length()) {
_ok = false;
return;
}
PathPart::Type type { PathPart::Type::Unknown };
size_t length { 0ul };
size_t offset { 0ul };
const char* p { _path.c_str() };
if (*p == '\0') {
goto error;
}
_parts.reserve(std::count(_path.begin(), _path.end(), '/') + 1);
start:
type = PathPart::Type::Unknown;
length = 0;
offset = p - _path.c_str();
switch (*p) {
case '+':
goto parse_single_wildcard;
case '#':
goto parse_multi_wildcard;
case '/':
default:
goto parse_value;
}
parse_value:
type = PathPart::Type::Value;
switch (*p) {
case '+':
case '#':
goto error;
case '/':
case '\0':
goto push_result;
}
++p;
++length;
goto parse_value;
parse_single_wildcard:
type = PathPart::Type::SingleWildcard;
++p;
switch (*p) {
case '/':
++p;
case '\0':
goto push_result;
}
goto error;
parse_multi_wildcard:
type = PathPart::Type::MultiWildcard;
++p;
if (*p == '\0') {
goto push_result;
}
goto error;
push_result:
emplace_back(type, offset, length);
if (*p == '/') {
++p;
goto start;
} else if (*p != '\0') {
goto start;
}
goto success;
error:
_ok = false;
_parts.clear();
return;
success:
_ok = true;
}
// match when, for example, given the path 'topic/one/two/three' and pattern 'topic/+/two/+'
bool PathParts::match(const PathParts& path) const {
if (!_ok || !path) {
return false;
}
auto lhs = begin();
auto lhs_end = end();
auto rhs = path.begin();
auto rhs_end = path.end();
loop:
if (lhs == lhs_end) {
goto check_end;
}
switch ((*lhs).type) {
case PathPart::Type::Value:
if (
(rhs != rhs_end)
&& ((*rhs).type == PathPart::Type::Value)
&& ((*rhs).length == (*lhs).length)
) {
if (0 == std::memcmp(
_path.c_str() + (*lhs).offset,
path.path().c_str() + (*rhs).offset,
(*rhs).length))
{
std::advance(lhs, 1);
std::advance(rhs, 1);
goto loop;
}
}
goto error;
case PathPart::Type::SingleWildcard:
if (
(rhs != rhs_end)
&& ((*rhs).type == PathPart::Type::Value)
) {
std::advance(lhs, 1);
std::advance(rhs, 1);
goto loop;
}
goto error;
case PathPart::Type::MultiWildcard:
if (std::next(lhs) == lhs_end) {
while (rhs != rhs_end) {
if ((*rhs).type != PathPart::Type::Value) {
goto error;
}
std::advance(rhs, 1);
}
lhs = lhs_end;
break;
}
goto error;
case PathPart::Type::Unknown:
goto error;
};
check_end:
if ((lhs == lhs_end) && (rhs == rhs_end)) {
return true;
}
error:
return false;
}
String ApiRequest::wildcard(int index) const {
if (index < 0) {
index = std::abs(index + 1);
}
if (std::abs(index) >= _pattern.parts().size()) {
return _empty_string();
}
int counter { 0 };
auto& pattern = _pattern.parts();
for (unsigned int part = 0; part < pattern.size(); ++part) {
auto& lhs = pattern[part];
if (PathPart::Type::SingleWildcard == lhs.type) {
if (counter == index) {
auto& rhs = _parts.parts()[part];
return _parts.path().substring(rhs.offset, rhs.offset + rhs.length);
}
++counter;
}
}
return _empty_string();
}
size_t ApiRequest::wildcards() const {
size_t result { 0ul };
for (auto& part : _pattern) {
if (PathPart::Type::SingleWildcard == part.type) {
++result;
}
}
return result;
}
// -----------------------------------------------------------------------------
#if API_SUPPORT
bool _apiAccepts(AsyncWebServerRequest* request, const __FlashStringHelper* str) {
auto* header = request->getHeader(F("Accept"));
if (header) {
return
(header->value().indexOf(F("*/*")) >= 0)
|| (header->value().indexOf(str) >= 0);
}
return false;
}
bool _apiAcceptsText(AsyncWebServerRequest* request) {
return _apiAccepts(request, F("text/plain"));
}
bool _apiAcceptsJson(AsyncWebServerRequest* request) {
return _apiAccepts(request, F("application/json"));
}
bool _apiMatchHeader(AsyncWebServerRequest* request, const __FlashStringHelper* key, const __FlashStringHelper* value) {
auto* header = request->getHeader(key);
if (header) {
return header->value().equals(value);
}
return false;
}
bool _apiIsJsonContent(AsyncWebServerRequest* request) {
return _apiMatchHeader(request, F("Content-Type"), F("application/json"));
}
bool _apiIsFormDataContent(AsyncWebServerRequest* request) {
return _apiMatchHeader(request, F("Content-Type"), F("application/x-www-form-urlencoded"));
}
// Because the webserver request is split between multiple separate function invocations, we need to preserve some state.
// TODO: in case we are dealing with multicore, perhaps enforcing static-size data structs instead of the vector would we better,
// to avoid calling generic malloc when paths are parsed?
//
// Some quirks to deal with:
// - handleBody is called before handleRequest, and there's no way to signal completion / success of both callbacks to the server
// - Server never checks for request closing in filter or canHandle, so if we don't want to handle large content-length, it
// will still flow through the lwip backend.
// - `request->_tempObject` is used to keep API request state, but it's just a plain void pointer
// - `request->send(..., payload)` creates a heap-allocated `reponse` object that will copy the payload and tracks it by a basic pointer.
// In case we call `request->send` a 2nd time (regardless of the type of the send()), it creates a 2nd object without de-allocating the 1st one.
// - espasyncwebserver will `free(_tempObject)` when request is disconnected, but only after this callbackhandler is done.
// make sure it's set to nullptr via `AsyncWebServerRequest::onDisconnect`
// - ALL headers are parsed (and we could access those during filter and canHandle callbacks), but we need to explicitly
// request them to stay in memory so that the actual handler can work with them
void _apiAttachHelper(AsyncWebServerRequest& request, ApiRequestHelper&& helper) {
request._tempObject = new ApiRequestHelper(std::move(helper));
request.onDisconnect([&]() {
auto* ptr = reinterpret_cast<ApiRequestHelper*>(request._tempObject);
delete ptr;
request._tempObject = nullptr;
});
request.addInterestingHeader(F("Api-Key"));
}
class ApiBaseWebHandler : public AsyncWebHandler {
public:
ApiBaseWebHandler() = delete;
ApiBaseWebHandler(const ApiBaseWebHandler&) = delete;
ApiBaseWebHandler(ApiBaseWebHandler&&) = delete;
// In case this needs to be copied or moved, ensure PathParts copy references the new object's string
template <typename Pattern>
explicit ApiBaseWebHandler(Pattern&& pattern) :
_pattern(std::forward<Pattern>(pattern)),
_parts(_pattern)
{}
const String& pattern() const {
return _pattern;
}
const PathParts& parts() const {
return _parts;
}
private:
String _pattern;
PathParts _parts;
};
// 'Modernized' API configuration:
// - `Api-Key` header for both GET and PUT
// - Parse request body as JSON object. Limited to LWIP internal buffer size, and will also break when client
// does weird stuff and PUTs data in multiple packets b/c only the initial packet is parsed.
// - Same as the text/plain, when ApiRequest::handle was not called it will then call GET
//
// TODO: bump to arduinojson v6 to handle partial / broken data payloads
// TODO: somehow detect partial data and buffer (optionally)
// TODO: POST instead of PUT?
class ApiJsonWebHandler final : public ApiBaseWebHandler {
public:
static constexpr size_t BufferSize { API_JSON_BUFFER_SIZE };
struct ReadOnlyStream : public Stream {
ReadOnlyStream() = delete;
explicit ReadOnlyStream(const uint8_t* buffer, size_t size) :
_buffer(buffer),
_size(size)
{}
int available() override {
return _size - _index;
}
int peek() override {
if (_index < _size) {
return static_cast<int>(_buffer[_index]);
}
return -1;
}
int read() override {
auto peeked = peek();
if (peeked >= 0) {
++_index;
}
return peeked;
}
// since we are fixed in size, no need for any timeouts and the only available option is to return full chunk of data
size_t readBytes(uint8_t* ptr, size_t size) override {
if ((_index < _size) && ((_size - _index) >= size)) {
std::copy(_buffer + _index, _buffer + _index + size, ptr);
_index += size;
return size;
}
return 0;
}
size_t readBytes(char* ptr, size_t size) override {
return readBytes(reinterpret_cast<uint8_t*>(ptr), size);
}
void flush() override {
}
size_t write(const uint8_t*, size_t) override {
return 0;
}
size_t write(uint8_t) override {
return 0;
}
const uint8_t* _buffer;
const size_t _size;
size_t _index { 0 };
};
ApiJsonWebHandler() = delete;
ApiJsonWebHandler(const ApiJsonWebHandler&) = delete;
ApiJsonWebHandler(ApiJsonWebHandler&&) = delete;
template <typename Path, typename Callback>
ApiJsonWebHandler(Path&& path, Callback&& get, Callback&& put) :
ApiBaseWebHandler(std::forward<Path>(path)),
_get(std::forward<Callback>(get)),
_put(std::forward<Callback>(put))
{}
bool isRequestHandlerTrivial() override {
return true;
}
bool canHandle(AsyncWebServerRequest* request) override {
if (!apiEnabled()) {
return false;
}
if (!_apiAcceptsJson(request)) {
return false;
}
auto helper = ApiRequestHelper(*request, parts());
if (helper.match() && apiAuthenticate(request)) {
switch (request->method()) {
case HTTP_HEAD:
return true;
case HTTP_PUT:
if (!_apiIsJsonContent(request)) {
return false;
}
if (!_put) {
return false;
}
case HTTP_GET:
if (!_get) {
return false;
}
break;
default:
return false;
}
_apiAttachHelper(*request, std::move(helper));
return true;
}
return false;
}
void _handleGet(AsyncWebServerRequest* request, ApiRequest& apireq) {
DynamicJsonBuffer jsonBuffer(API_JSON_BUFFER_SIZE);
JsonObject& root = jsonBuffer.createObject();
if (!_get(apireq, root)) {
request->send(500);
return;
}
if (!apireq.done()) {
AsyncResponseStream *response = request->beginResponseStream("application/json", root.measureLength() + 1);
root.printTo(*response);
request->send(response);
return;
}
request->send(500);
}
void _handlePut(AsyncWebServerRequest* request, uint8_t* data, size_t size) {
// XXX: arduinojson v5 de-serializer will happily read garbage from raw ptr, since there's no length limit
// this is fixed in v6 though. for now, use a wrapper, but be aware that this actually uses more mem for the jsonbuffer
DynamicJsonBuffer jsonBuffer(API_JSON_BUFFER_SIZE);
ReadOnlyStream stream(data, size);
JsonObject& root = jsonBuffer.parseObject(stream);
if (!root.success()) {
request->send(500);
return;
}
auto& helper = *reinterpret_cast<ApiRequestHelper*>(request->_tempObject);
auto apireq = helper.request();
if (!_put(apireq, root)) {
request->send(500);
return;
}
if (!apireq.done()) {
_handleGet(request, apireq);
}
return;
}
void handleBody(AsyncWebServerRequest* request, uint8_t* data, size_t len, size_t, size_t total) override {
if (total && (len == total)) {
_handlePut(request, data, total);
}
}
void handleRequest(AsyncWebServerRequest* request) override {
auto& helper = *reinterpret_cast<ApiRequestHelper*>(request->_tempObject);
switch (request->method()) {
case HTTP_HEAD:
request->send(204);
return;
case HTTP_GET: {
auto apireq = helper.request();
_handleGet(request, apireq);
return;
}
// see handleBody()
case HTTP_PUT:
break;
default:
request->send(405);
break;
}
}
const String& pattern() const {
return ApiBaseWebHandler::pattern();
}
const PathParts& parts() const {
return ApiBaseWebHandler::parts();
}
private:
ApiJsonHandler _get;
ApiJsonHandler _put;
};
// ESPurna legacy API configuration
// - ?apikey=... to authorize in GET or PUT
// - ?anything=... for input data (common key is "value")
// MUST correctly override isRequestHandlerTrivial() to allow auth with PUT
// (i.e. so that ESPAsyncWebServer parses the body and adds form-data to request params list)
class ApiBasicWebHandler final : public ApiBaseWebHandler {
public:
template <typename Path, typename Callback>
ApiBasicWebHandler(Path&& path, Callback&& get, Callback&& put) :
ApiBaseWebHandler(std::forward<Path>(path)),
_get(std::forward<Callback>(get)),
_put(std::forward<Callback>(put))
{}
bool isRequestHandlerTrivial() override {
return false;
}
bool canHandle(AsyncWebServerRequest* request) override {
if (!apiEnabled()) {
return false;
}
if (!_apiAcceptsText(request)) {
return false;
}
switch (request->method()) {
case HTTP_HEAD:
case HTTP_GET:
break;
case HTTP_PUT:
if (!_apiIsFormDataContent(request)) {
return false;
}
break;
default:
return false;
}
auto helper = ApiRequestHelper(*request, parts());
if (helper.match()) {
_apiAttachHelper(*request, std::move(helper));
return true;
}
return false;
}
void handleRequest(AsyncWebServerRequest* request) override {
if (!apiAuthenticate(request)) {
request->send(403);
return;
}
auto method = request->method();
const bool is_put = (
(!apiRestFul()|| (HTTP_PUT == method))
&& request->hasParam("value", HTTP_PUT == method)
);
switch (method) {
case HTTP_HEAD:
request->send(204);
return;
case HTTP_GET:
case HTTP_PUT: {
auto& helper = *reinterpret_cast<ApiRequestHelper*>(request->_tempObject);
auto apireq = helper.request();
if (is_put) {
if (!_put(apireq)) {
request->send(500);
return;
}
if (apireq.done()) {
return;
}
}
if (!_get(apireq)) {
request->send(500);
return;
}
if (!apireq.done()) {
request->send(204);
return;
}
break;
}
default:
request->send(405);
break;
}
}
const ApiBasicHandler& get() const {
return _get;
}
const ApiBasicHandler& put() const {
return _put;
}
const String& pattern() const {
return ApiBaseWebHandler::pattern();
}
const PathParts& parts() const {
return ApiBaseWebHandler::parts();
}
private:
ApiBasicHandler _get;
ApiBasicHandler _put;
};
// -----------------------------------------------------------------------------
namespace {
std::forward_list<ApiBaseWebHandler*> _apis;
template <typename Handler, typename Callback>
void _apiRegister(const String& path, Callback&& get, Callback&& put) {
// `String` is a given, since we *do* need to construct this dynamically in sensors
auto* ptr = new Handler(String(F(API_BASE_PATH)) + path, std::forward<Callback>(get), std::forward<Callback>(put));
webServer().addHandler(reinterpret_cast<AsyncWebHandler*>(ptr));
_apis.emplace_front(ptr);
}
} // namespace
void apiRegister(const String& path, ApiBasicHandler&& get, ApiBasicHandler&& put) {
_apiRegister<ApiBasicWebHandler>(path, std::move(get), std::move(put));
}
void apiRegister(const String& path, ApiJsonHandler&& get, ApiJsonHandler&& put) {
_apiRegister<ApiJsonWebHandler>(path, std::move(get), std::move(put));
}
void apiSetup() {
apiRegister(F("list"),
[](ApiRequest& request) {
String paths;
for (auto& api : _apis) {
paths += api->pattern() + "\r\n";
}
request.send(paths);
return true;
},
nullptr
);
apiRegister(F("rpc"),
nullptr,
[](ApiRequest& request) {
if (rpcHandleAction(request.param(F("action")))) {
return apiOk(request);
}
return apiError(request);
}
);
}
bool apiOk(ApiRequest& request) {
request.send(F("OK"));
return true;
}
bool apiError(ApiRequest& request) {
request.send(F("ERROR"));
return true;
}
#endif // API_SUPPORT