esp-firewall/SourceCode/arduino/lib/Firewall/Firewall.cpp

#include "Firewall.h"

ESPFirewall::ESPFirewall(int port)
{
    log_i("Starting Firewall-API on %i", port);
    this->firewall_api = new AsyncWebServer(port);
    this->setup_routing();
}

void ESPFirewall::prepare_firewall_json(DynamicJsonDocument &json, firewall_rule_t *rule)
{
    json["key"] = rule->key;
    json["source"] = rule->source;
    json["destination"] = rule->destination;
    json["protocol"] = rule->protocol;
    json["target"] = rule->target;
}

void ESPFirewall::add_rule_to_firewall(firewall_rule_t *rule)
{
    firewall_rule_t *temp;
    if (head == NULL)
    {
        head = rule;
        rule->next = NULL;
        return;
    }
    temp = head;
    while (temp->next != NULL)
    {
        temp = temp->next;
    }
    temp->next = rule;
    rule->next = NULL;
    return;
}

void ESPFirewall::get_firewall_rules_handler(AsyncWebServerRequest *request)
{
    firewall_rule_t *ptr = this->head;
    DynamicJsonDocument json(1024);
    String response;
    json["amount"] = amount_of_rules;
    JsonArray rules = json.createNestedArray("rules");
    while (ptr != NULL)
    {
        JsonObject rule = rules.createNestedObject();
        rule["key"] = ptr->key;
        rule["source"] = ptr->source;
        rule["destination"] = ptr->destination;
        rule["protocol"] = ptr->protocol;
        rule["target"] = ptr->target;
        ptr = ptr->next;
    }
    serializeJson(json, response);
    request->send(200, "application/json", response);
}

void ESPFirewall::get_firewall_rule_handler(AsyncWebServerRequest *request)
{
    int rule_number = request->pathArg(0).toInt();
    DynamicJsonDocument json(1024);
    String response;
    firewall_rule_t *current = this->head;

    if (head == NULL)
    {
        json["message"] = "list is empty";
        serializeJson(json, response);
        request->send(500, "application/json", response);
        return;
    }

    while (current->key != rule_number)
    {
        if (current->next == NULL)
        {
            json["message"] = "rule not found";
            serializeJson(json, response);
            request->send(500, "application/json", response);
            return;
        }
        else
        {
            current = current->next;
        }
    }
    prepare_firewall_json(json, current);
    serializeJson(json, response);
    request->send(200, "application/json", response);
}

void ESPFirewall::post_firewall_handler(AsyncWebServerRequest *request)
{
    DynamicJsonDocument json(1024);
    String response;
    int response_code;
    if (request_has_firewall_parameter(request))
    {
        firewall_rule_t *rule = (firewall_rule_t *)malloc(sizeof(firewall_rule_t));
        rule->key = ++amount_of_rules;

        const char *source = request->arg("source").c_str();
        strcpy(rule->source, strlen(source) <= IP4ADDR_STRLEN_MAX ? source : "-");

        const char *destination = request->arg("destination").c_str();
        strcpy(rule->destination, strlen(destination) <= IP4ADDR_STRLEN_MAX ? destination : "-");

        const char *protocol = request->arg("protocol").c_str();
        strcpy(rule->protocol, strlen(protocol) <= PROTOCOL_LENGTH ? protocol : "-");

        const char *target = request->arg("target").c_str();
        strcpy(rule->target, strlen(target) <= TARGET_LENGTH ? target : "-");

        add_rule_to_firewall(rule);

        prepare_firewall_json(json, rule);
        response_code = 200;
    }
    else
    {
        json["message"] = "not enough parameter provided";
        response_code = 400;
    }
    serializeJson(json, response);
    request->send(response_code, "application/json", response);
}

void ESPFirewall::not_found(AsyncWebServerRequest *request)
{
    DynamicJsonDocument json(1024);
    String response;
    json["message"] = "not found";
    serializeJson(json, response);
    request->send(404, "application/json", response);
}

bool ESPFirewall::request_has_firewall_parameter(AsyncWebServerRequest *request)
{
    return request->hasArg("source") || request->hasArg("destination") || request->hasArg("protocol") || request->hasArg("target");
}

void ESPFirewall::setup_routing()
{
    firewall_api->on("^\\/api/v1/firewall\\/([0-9]+)$", HTTP_GET, std::bind(&ESPFirewall::get_firewall_rule_handler, this, std::placeholders::_1));
    firewall_api->on("/api/v1/firewall", HTTP_GET, std::bind(&ESPFirewall::get_firewall_rules_handler, this, std::placeholders::_1));
    firewall_api->on("/api/v1/firewall", HTTP_POST, std::bind(&ESPFirewall::post_firewall_handler, this, std::placeholders::_1));
    firewall_api->onNotFound(std::bind(&ESPFirewall::not_found, this, std::placeholders::_1));
    this->firewall_api->begin();
}