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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <dirent.h>
#include <sys/types.h>
#include <fcgiapp.h>
#include <iostream>
#include <functional>
#include <filesystem>
#include <random>
#include <regex>
#include <string>
#include <unordered_map>
#include <boost/algorithm/string/predicate.hpp>
#include <boost/algorithm/string/trim.hpp>
#include <boost/property_tree/xml_parser.hpp>
#include "config.h"
#include "file.h"
namespace pt = boost::property_tree;
using namespace std::string_literals;
namespace fs = std::filesystem;
namespace {
uint32_t checksum32(const std::string& s)
{
uint32_t result{0};
for (int i = 0; i < s.size(); i++) {
result = ((result >> 1) | ((result & 1) << 31)) ^ (s[i] & 0xFF);
}
return result & 0x7FFFFFFF;
}
fs::path data_path;
std::string generate_id()
{
static std::random_device r;
static std::default_random_engine e1(r());
static std::uniform_int_distribution<int> uniform_dist(0, 15);
// limit tries
for (int j = 0; j < 100000; j++) {
std::string result;
for (int i = 0; i < 6; i++) {
char c{static_cast<char>('0' + uniform_dist(e1))};
if (c > '9')
c = c - '9' + 'a';
result.push_back(c);
}
fs::path path{data_path / result};
if (!fs::exists(path))
return result;
}
return "endofcodes";
}
void setFileById(const std::string& data, const std::string& id)
{
fs::path path{data_path / id};
// skip if it doesn't exists
if (data.empty() && !fs::exists(path))
return;
// clean up immediately, if appropriate
if (data.empty()) {
fs::remove(path);
return;
}
File::setFile(path, data);
}
std::string getFileById(const std::string& id)
{
fs::path path{data_path / id};
if (!fs::exists(path))
return {};
return File::getFile(path);
}
}
int main(void)
{
Config config;
data_path = config.getDataPath();
int result = FCGX_Init();
if (result != 0) { // error on init
fprintf(stderr, "Error: FCGX_Init()\n");
return 1;
}
result = FCGX_IsCGI();
if (result) {
fprintf(stderr, "Error: No FCGI environment available.\n");
return 1;
}
FCGX_Request request;
result = FCGX_InitRequest(&request, 0, 0);
if (result != 0) {
fprintf(stderr, "Error: FCGX_InitRequest()\n");
return 1;
}
while (FCGX_Accept_r(&request) >= 0) {
try {
char* method = FCGX_GetParam("REQUEST_METHOD", request.envp);
// POST for server actions, changes
if (!strcmp(method, "POST")) {
size_t contentLength { std::stoul(FCGX_GetParam("CONTENT_LENGTH", request.envp)) };
std::string postData(contentLength, '\0'); // contentLength number of bytes, initialize with 0
if (FCGX_GetStr(postData.data(), contentLength, request.in) != static_cast<int>(contentLength)) {
throw std::runtime_error("Bad data read: Content length mismatch.\r\n");
}
// postData contains POST data
std::string contentType(FCGX_GetParam("CONTENT_TYPE", request.envp));
std::string xmlData = postData; // default: interpret whole POST data as xml request
pt::ptree xml;
std::istringstream ss{xmlData};
pt::xml_parser::read_xml(ss, xml);
std::string command {xml.get<std::string>("request.command")};
if (command == "modify") {
std::string id {xml.get<std::string>("request.id")};
std::string data {xml.get<std::string>("request.data")};
setFileById(data, id);
FCGX_PutS("Content-Type: text/plain\r\n\r\n", request.out);
} else if (command == "getfile") {
std::string id {xml.get<std::string>("request.id")};
std::string filedata {getFileById(id)};
if (filedata.size() > 30000000)
throw std::runtime_error("File too big");
FCGX_PutS("Content-Type: application/octet-stream\r\n", request.out);
FCGX_FPrintF(request.out, "Content-Length: %d\r\n\r\n", filedata.size());
FCGX_PutStr(filedata.c_str(), filedata.size(), request.out);
} else if (command == "checkupdate") {
std::string id {xml.get<std::string>("request.id")};
std::string checksum_s {xml.get<std::string>("request.checksum")};
uint32_t checksum{static_cast<uint32_t>(stoul(checksum_s))};
//std::cout << "Checksum JS: " << checksum_s << std::endl;
//std::cout << "Checksum C++: " << checksum32(filedata) << std::endl;
std::string filedata {getFileById(id)};
if (checksum != checksum32(filedata)) {
//std::cout << "Sending change..." << std::endl;
FCGX_PutS("Content-Type: application/octet-stream\r\n", request.out);
FCGX_FPrintF(request.out, "Content-Length: %d\r\n\r\n", filedata.size());
FCGX_PutStr(filedata.c_str(), filedata.size(), request.out);
} else {
//std::cout << "No change..." << std::endl;
FCGX_PutS("Content-Type: text/plain\r\n\r\n", request.out);
FCGX_PutS("No change.\r\n", request.out);
}
} else if (command == "newid") {
FCGX_PutS("Content-Type: text/plain\r\n\r\n", request.out);
FCGX_PutS(generate_id().c_str(), request.out);
} else {
throw std::runtime_error("Bad command: "s + command);
}
} else {
throw std::runtime_error("Unsupported method.\r\n");
}
} catch (const std::runtime_error& ex) {
FCGX_PutS("Status: 500 Internal Server Error\r\n", request.out);
FCGX_PutS("Content-Type: text/html\r\n\r\n", request.out);
FCGX_FPrintF(request.out, "Error: %s\r\n", ex.what());
} catch (const std::exception& ex) {
FCGX_PutS("Status: 500 Internal Server Error\r\n", request.out);
FCGX_PutS("Content-Type: text/html\r\n\r\n", request.out);
FCGX_FPrintF(request.out, "Unknown exception: %s\r\n", ex.what());
}
}
return 0;
}
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