Parse REQUEST_URI

src/main.cpp

@@ -16,9 +16,12 @@
 
 #include "config.hpp"
 #include "helpers.hpp"
+#include "request.hpp"
 #include "version.hpp"
 
+#include <cstring>
 #include <iostream>
+#include <stdexcept>
 #include <string>
 
 int main(int /*argc*/, char * /*argv*/[]) {
@@ -26,14 +29,28 @@ int main(int /*argc*/, char * /*argv*/[]) {
 
     std::cout << "Server: libravatarserv/" << version << '\n';
 
+    try {
         const std::string uri{read_env("REQUEST_URI")};
         if (uri.empty()) {
             std::cout << "Status: 400 Bad Request\n\n";
-        std::cerr << "ERROR: REQUEST_URI is empty.\n";
-        return 1;
+            throw std::runtime_error{"REQUEST_URI is empty"};
         }
 
         auto cfg{config::read()};
 
+        auto req{request::parse(uri)};
+        if (req.fallback.empty()) {
+            req.fallback = cfg.default_fallback;
+        }
+        std::cout << "  HASH: " << req.hash << "\n  SIZE: " << req.size
+                  << "\n  FALLBACK: " << req.fallback << '\n';
+
+    } catch (const std::runtime_error &e) {
+        if (std::strlen(e.what()) != 0) {
+            std::cerr << "ERROR: " << e.what() << '\n';
+        }
+        return 1;
+    }
+
     return 0;
 }

src/request.cpp

@@ -0,0 +1,91 @@
+/*  This file is part of libravatarserv.
+ *  Copyright © 2022 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "request.hpp"
+
+#include <algorithm>
+#include <cstdint>
+#include <iostream>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+
+namespace libravatarserv::request {
+
+request parse(const std::string_view uri) {
+    constexpr std::uint8_t offset{8};
+    if (uri.substr(0, offset) != "/avatar/"
+        || uri.find("..", offset) != std::string_view::npos) {
+        std::cout << "Status: 400 Bad Request\n\n";
+        throw std::runtime_error{"Invalid URL"};
+    }
+
+    request req;
+    req.size = 80;
+
+    size_t pos{uri.find('?')};
+    if (pos == std::string_view::npos) {
+        pos = uri.size();
+    }
+    req.hash.resize(pos - offset);
+    std::transform(uri.begin() + offset, uri.begin() + pos, req.hash.begin(),
+                   ::tolower);
+
+    if (pos != uri.size()) {
+        std::string uri_rest;
+        uri_rest.resize(uri.size() - pos);
+        std::transform(uri.begin() + pos, uri.end(), uri_rest.begin(),
+                       ::tolower);
+
+        auto strsize{get_parameter(uri_rest, "s")};
+        if (strsize.empty()) {
+            strsize = get_parameter(uri_rest, "size");
+        }
+        if (!strsize.empty()) {
+            try {
+                req.size = static_cast<int16_t>(std::stoul(strsize.data()));
+                if (req.size > 512) {
+                    req.size = 512;
+                } else if (req.size < 1) {
+                    req.size = 80;
+                }
+            } catch (...) {}
+        }
+
+        req.fallback = get_parameter(uri_rest, "d");
+        if (req.fallback.empty()) {
+            req.fallback = get_parameter(uri_rest, "default");
+        }
+    }
+
+    return req;
+}
+
+std::string_view get_parameter(const std::string_view uri,
+                               const std::string &parameter) {
+    size_t pos{uri.find("?" + parameter + "=")};
+    if (pos == std::string_view::npos) {
+        pos = uri.find("&" + parameter + "=");
+    }
+    if (pos != std::string_view::npos) {
+        pos += (2 + parameter.length());
+        return uri.substr(pos, uri.find('&', pos));
+    }
+
+    return {};
+}
+
+} // namespace libravatarserv::request

src/request.hpp

@@ -0,0 +1,39 @@
+/*  This file is part of libravatarserv.
+ *  Copyright © 2022 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBRAVATARSERV_REQUEST_HPP
+#define LIBRAVATARSERV_REQUEST_HPP
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+
+namespace libravatarserv::request {
+
+struct request {
+    std::string hash;
+    std::int16_t size;
+    std::string fallback;
+};
+
+[[nodiscard]] request parse(std::string_view uri);
+
+[[nodiscard]] std::string_view get_parameter(std::string_view uri,
+                                             const std::string &parameter);
+
+} // namespace libravatarserv::request
+
+#endif // LIBRAVATARSERV_REQUEST_HPP