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esp-firewall/SourceCode/arduino/lib/Firewall/Firewall.cpp
2022-04-19 21:15:55 +02:00

392 lines
13 KiB
C++

#include "Firewall.h"
ESPFirewall::ESPFirewall(const uint16_t api_port)
{
this->setup_eeprom();
this->setup_certificate();
this->firewall_api = new HTTPSServer(this->certificate, api_port, 5);
this->setup_routing();
log_i("Starting server...");
this->firewall_api->start();
if (this->firewall_api->isRunning())
{
log_i("Server ready.");
}
}
void ESPFirewall::handle_firewall_api_clients()
{
this->firewall_api->loop();
}
String ESPFirewall::protocol_to_string(firewall_protocol_t &protocol)
{
switch (protocol)
{
case FW_TCP:
return "TCP";
case FW_UDP:
return "UDP";
default:
return "ALL";
}
}
firewall_protocol_t ESPFirewall::string_to_protocol(std::string &protocol)
{
if (protocol.compare("TCP") == 0)
return FW_TCP;
else if (protocol.compare("UDP") == 0)
return FW_UDP;
else
return FW_ALL;
}
String ESPFirewall::target_to_string(firewall_target_t &target)
{
switch (target)
{
case FW_REJECT:
return "REJECT";
case FW_DROP:
return "DROP";
default:
return "ACCEPT";
}
}
firewall_target_t ESPFirewall::string_to_target(std::string &target)
{
if (target.compare("REJECT") == 0)
return FW_REJECT;
else if (target.compare("DROP") == 0)
return FW_DROP;
else
return FW_ACCEPT;
}
void ESPFirewall::setup_eeprom()
{
EEPROM.begin(this->eeprom_size);
this->amount_of_rules = EEPROM.read(this->eeprom_settings_head);
uint8_t security_number = EEPROM.read(this->eeprom_settings_head + 1);
if (this->amount_of_rules > 50 || security_number != this->security_number)
{
this->amount_of_rules = 0;
EEPROM.write(this->eeprom_settings_head, this->amount_of_rules);
EEPROM.write(this->eeprom_settings_head + 1, this->security_number);
EEPROM.commit();
}
log_i("Amount of existing Rules %i", this->amount_of_rules);
this->eeprom_read_firewall_rules();
}
void ESPFirewall::eeprom_write_firewall_rule(firewall_rule_t *rule_ptr)
{
EEPROM.write(this->eeprom_settings_head, this->amount_of_rules);
EEPROM.writeString(this->eeprom_rules_head, rule_ptr->source);
this->eeprom_rules_head += IP4ADDR_STRLEN_MAX;
EEPROM.writeString(this->eeprom_rules_head, rule_ptr->destination);
this->eeprom_rules_head += IP4ADDR_STRLEN_MAX;
EEPROM.write(this->eeprom_rules_head, rule_ptr->protocol);
this->eeprom_rules_head += sizeof(firewall_protocol_t);
EEPROM.write(this->eeprom_rules_head, rule_ptr->target);
this->eeprom_rules_head += sizeof(firewall_target_t);
EEPROM.commit();
}
void ESPFirewall::eeprom_write_firewall_rules()
{
this->eeprom_rules_head = eeprom_start_firewall_rules;
firewall_rule_t *rule_ptr = this->head;
while (rule_ptr != NULL)
{
this->eeprom_write_firewall_rule(rule_ptr);
rule_ptr = rule_ptr->next;
}
}
void ESPFirewall::eeprom_read_firewall_rule(uint8_t &eeprom_address, uint8_t &rule_nr)
{
firewall_rule_t *rule_ptr = (firewall_rule_t *)malloc(sizeof(firewall_rule_t));
rule_ptr->key = rule_nr;
strcpy(rule_ptr->source, EEPROM.readString(eeprom_address).c_str());
eeprom_address += IP4ADDR_STRLEN_MAX;
strcpy(rule_ptr->destination, EEPROM.readString(eeprom_address).c_str());
eeprom_address += IP4ADDR_STRLEN_MAX;
rule_ptr->protocol = static_cast<firewall_protocol_t>(EEPROM.read(eeprom_address));
eeprom_address += sizeof(firewall_protocol_t);
rule_ptr->target = static_cast<firewall_target_t>(EEPROM.read(eeprom_address));
eeprom_address += sizeof(firewall_target_t);
add_rule_to_firewall(rule_ptr);
log_i("%s, %s, %s, %s",
rule_ptr->source,
rule_ptr->destination,
protocol_to_string(rule_ptr->protocol),
target_to_string(rule_ptr->target));
}
void ESPFirewall::eeprom_read_firewall_rules()
{
uint8_t eeprom_address = eeprom_start_firewall_rules;
for (uint8_t i = 1; i <= this->amount_of_rules; i++)
{
eeprom_read_firewall_rule(eeprom_address, i);
}
}
void ESPFirewall::add_rule_to_firewall(firewall_rule_t *rule_ptr)
{
firewall_rule_t *temp;
if (this->head == NULL)
{
this->head = rule_ptr;
rule_ptr->next = NULL;
return;
}
temp = this->head;
while (temp->next != NULL)
{
temp = temp->next;
}
temp->next = rule_ptr;
rule_ptr->next = NULL;
return;
}
firewall_rule_t *ESPFirewall::get_rule_from_firewall(uint8_t key)
{
firewall_rule_t *rule_ptr = this->head;
if (this->head == NULL)
{
return NULL;
}
while (rule_ptr->key != key)
{
if (rule_ptr->next == NULL)
{
return NULL;
}
else
{
rule_ptr = rule_ptr->next;
}
}
return rule_ptr;
}
bool ESPFirewall::delete_rule_from_firewall(uint8_t key)
{
if (this->head == NULL)
{
return false;
}
firewall_rule_t *current_rule_ptr = this->head;
firewall_rule_t *previous_rule_ptr = NULL;
firewall_rule_t *temp = NULL;
while (current_rule_ptr->key != key)
{
if (current_rule_ptr->next == NULL)
{
return false;
}
else
{
previous_rule_ptr = current_rule_ptr;
current_rule_ptr = current_rule_ptr->next;
}
}
if (current_rule_ptr == this->head)
{
this->head = head->next;
temp = this->head;
}
else
{
previous_rule_ptr->next = current_rule_ptr->next;
temp = previous_rule_ptr->next;
}
while (temp != NULL)
{
temp->key--;
temp = temp->next;
}
free(current_rule_ptr);
this->amount_of_rules--;
this->eeprom_write_firewall_rules();
return true;
}
void ESPFirewall::setup_certificate()
{
log_i("Creating the certificate...");
this->certificate = new SSLCert();
int createCertResult = createSelfSignedCert(
*this->certificate,
KEYSIZE_2048,
"CN=myesp32.local,O=Firewall,C=DE",
"20220101000000",
"20320101000000");
if (createCertResult != 0)
{
log_e("Cerating certificate failed. Error Code = 0x%02X, check SSLCert.hpp for details", createCertResult);
while (true)
delay(500);
}
log_i("Creating the certificate was successful");
}
void ESPFirewall::setup_routing()
{
ResourceNode *get_firewall_rule = new ResourceNode("/api/v1/firewall/*", "GET", std::bind(&ESPFirewall::get_firewall_rule_handler, this, std::placeholders::_1, std::placeholders::_2));
ResourceNode *get_firewall_rules = new ResourceNode("/api/v1/firewall", "GET", std::bind(&ESPFirewall::get_firewall_rules_handler, this, std::placeholders::_1, std::placeholders::_2));
ResourceNode *post_firewall = new ResourceNode("/api/v1/firewall", "POST", std::bind(&ESPFirewall::post_firewall_handler, this, std::placeholders::_1, std::placeholders::_2));
ResourceNode *delete_firewall = new ResourceNode("/api/v1/firewall/*", "DELETE", std::bind(&ESPFirewall::delete_firewall_handler, this, std::placeholders::_1, std::placeholders::_2));
ResourceNode *restart_device = new ResourceNode("/api/v1/device/restart", "GET", std::bind(&ESPFirewall::restart_device_handler, this, std::placeholders::_1, std::placeholders::_2));
ResourceNode *not_found = new ResourceNode("", "GET", std::bind(&ESPFirewall::not_found_handler, this, std::placeholders::_1, std::placeholders::_2));
this->firewall_api->registerNode(get_firewall_rule);
this->firewall_api->registerNode(get_firewall_rules);
this->firewall_api->registerNode(post_firewall);
this->firewall_api->registerNode(delete_firewall);
this->firewall_api->setDefaultNode(restart_device);
this->firewall_api->setDefaultNode(not_found);
}
void ESPFirewall::json_generic_response(HTTPResponse *response, String serialized, int response_code)
{
response->setHeader("Content-Type", "application/json");
response->setStatusCode(response_code);
response->println(serialized);
}
void ESPFirewall::json_message_response(HTTPResponse *response, String message, int response_code)
{
response->setHeader("Content-Type", "application/json");
response->setStatusCode(response_code);
StaticJsonDocument<96> json;
String serialized;
json["message"] = message;
serializeJson(json, serialized);
response->println(serialized);
}
String ESPFirewall::construct_json_firewall_rule(firewall_rule_t *rule_ptr)
{
StaticJsonDocument<256> doc;
doc["key"] = rule_ptr->key;
doc["source"] = rule_ptr->source;
doc["destination"] = rule_ptr->destination;
doc["protocol"] = protocol_to_string(rule_ptr->protocol);
doc["target"] = target_to_string(rule_ptr->target);
String response;
serializeJson(doc, response);
return response;
}
String ESPFirewall::construct_json_firewall()
{
firewall_rule_t *rule_ptr = this->head;
// Size for approx. 12 Rules
StaticJsonDocument<2048> doc;
String response;
doc["amount_of_rules"] = this->amount_of_rules;
JsonArray rules = doc.createNestedArray("rules");
while (rule_ptr != NULL)
{
JsonObject rule = rules.createNestedObject();
rule["key"] = rule_ptr->key;
rule["source"] = rule_ptr->source;
rule["destination"] = rule_ptr->destination;
rule["protocol"] = protocol_to_string(rule_ptr->protocol);
rule["target"] = target_to_string(rule_ptr->target);
rule_ptr = rule_ptr->next;
}
serializeJson(doc, response);
return response;
}
void ESPFirewall::not_found_handler(HTTPRequest *request, HTTPResponse *response)
{
this->json_message_response(response, "not found", 404);
}
void ESPFirewall::restart_device_handler(HTTPRequest *request, HTTPResponse *response)
{
this->json_message_response(response, "restarting device in 2 sec", 200);
sleep(2000);
esp_restart();
}
void ESPFirewall::get_firewall_rule_handler(HTTPRequest *request, HTTPResponse *response)
{
ResourceParameters *params = request->getParams();
int rule_number = atoi(params->getPathParameter(0).c_str());
firewall_rule_t *rule_ptr = this->get_rule_from_firewall(rule_number);
if (rule_ptr == NULL)
{
this->json_message_response(response, "rule not found", 404);
}
else
{
response->setHeader("Content-Type", "application/json");
response->setStatusCode(200);
response->print(this->construct_json_firewall_rule(rule_ptr));
}
}
void ESPFirewall::get_firewall_rules_handler(HTTPRequest *request, HTTPResponse *response)
{
this->json_generic_response(response, this->construct_json_firewall(), 200);
}
bool ESPFirewall::request_has_firewall_parameter(ResourceParameters *params)
{
return params->isQueryParameterSet("source") || params->isQueryParameterSet("destination") || params->isQueryParameterSet("protocol") || params->isQueryParameterSet("target");
}
void ESPFirewall::post_firewall_handler(HTTPRequest *request, HTTPResponse *response)
{
ResourceParameters *params = request->getParams();
if (request_has_firewall_parameter(params))
{
firewall_rule_t *rule_ptr = (firewall_rule_t *)malloc(sizeof(firewall_rule_t));
rule_ptr->key = ++amount_of_rules;
// carefully copying c-string that is shorter then the destination char-array length
std::string source;
params->getQueryParameter("source", source);
strcpy(rule_ptr->source, source.length() <= IPV4ADDRESS_LENGTH ? source.c_str() : "");
std::string destination;
params->getQueryParameter("destination", destination);
strcpy(rule_ptr->destination, destination.length() <= IPV4ADDRESS_LENGTH ? destination.c_str() : "");
std::string protocol;
params->getQueryParameter("protocol", protocol);
rule_ptr->protocol = string_to_protocol(protocol);
std::string target;
params->getQueryParameter("target", target);
rule_ptr->target = string_to_target(target);
this->add_rule_to_firewall(rule_ptr);
this->eeprom_write_firewall_rule(rule_ptr);
this->json_generic_response(response, this->construct_json_firewall_rule(rule_ptr), 200);
}
else
{
this->json_message_response(response, "not enough parameter", 400);
}
}
void ESPFirewall::delete_firewall_handler(HTTPRequest *request, HTTPResponse *response)
{
ResourceParameters *params = request->getParams();
int rule_number = atoi(params->getPathParameter(0).c_str());
if (this->delete_rule_from_firewall(rule_number))
{
this->json_message_response(response, "firewall rule deleted", 200);
}
else
{
this->json_message_response(response, "cannot delete firewall rule", 500);
}
}