Files
c-relay/src/main.c
2025-09-03 20:39:06 -04:00

562 lines
20 KiB
C

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <pthread.h>
#include <sqlite3.h>
#include <libwebsockets.h>
// Include nostr_core_lib for Nostr functionality
#include "../nostr_core_lib/cjson/cJSON.h"
#include "../nostr_core_lib/nostr_core/nostr_core.h"
// Configuration
#define DEFAULT_PORT 8888
#define DEFAULT_HOST "127.0.0.1"
#define DATABASE_PATH "db/c_nostr_relay.db"
#define MAX_CLIENTS 100
// Global state
static sqlite3* g_db = NULL;
static int g_server_running = 1;
// Color constants for logging
#define RED "\033[31m"
#define GREEN "\033[32m"
#define YELLOW "\033[33m"
#define BLUE "\033[34m"
#define BOLD "\033[1m"
#define RESET "\033[0m"
// Logging functions
void log_info(const char* message) {
printf(BLUE "[INFO]" RESET " %s\n", message);
fflush(stdout);
}
void log_success(const char* message) {
printf(GREEN "[SUCCESS]" RESET " %s\n", message);
fflush(stdout);
}
void log_error(const char* message) {
printf(RED "[ERROR]" RESET " %s\n", message);
fflush(stdout);
}
void log_warning(const char* message) {
printf(YELLOW "[WARNING]" RESET " %s\n", message);
fflush(stdout);
}
// Signal handler for graceful shutdown
void signal_handler(int sig) {
if (sig == SIGINT || sig == SIGTERM) {
log_info("Received shutdown signal");
g_server_running = 0;
}
}
// Initialize database connection
int init_database() {
int rc = sqlite3_open(DATABASE_PATH, &g_db);
if (rc != SQLITE_OK) {
log_error("Cannot open database");
return -1;
}
log_success("Database connection established");
return 0;
}
// Close database connection
void close_database() {
if (g_db) {
sqlite3_close(g_db);
g_db = NULL;
log_info("Database connection closed");
}
}
// Store event in database
int store_event(cJSON* event) {
if (!g_db || !event) {
return -1;
}
// Extract event fields
cJSON* id = cJSON_GetObjectItem(event, "id");
cJSON* pubkey = cJSON_GetObjectItem(event, "pubkey");
cJSON* created_at = cJSON_GetObjectItem(event, "created_at");
cJSON* kind = cJSON_GetObjectItem(event, "kind");
cJSON* content = cJSON_GetObjectItem(event, "content");
cJSON* sig = cJSON_GetObjectItem(event, "sig");
cJSON* tags = cJSON_GetObjectItem(event, "tags");
if (!id || !pubkey || !created_at || !kind || !content || !sig) {
log_error("Invalid event - missing required fields");
return -1;
}
// Prepare SQL statement for event insertion
const char* sql =
"INSERT INTO event (id, pubkey, created_at, kind, content, sig) "
"VALUES (?, ?, ?, ?, ?, ?)";
sqlite3_stmt* stmt;
int rc = sqlite3_prepare_v2(g_db, sql, -1, &stmt, NULL);
if (rc != SQLITE_OK) {
log_error("Failed to prepare event insert statement");
return -1;
}
// Bind parameters
sqlite3_bind_text(stmt, 1, cJSON_GetStringValue(id), -1, SQLITE_STATIC);
sqlite3_bind_text(stmt, 2, cJSON_GetStringValue(pubkey), -1, SQLITE_STATIC);
sqlite3_bind_int64(stmt, 3, (sqlite3_int64)cJSON_GetNumberValue(created_at));
sqlite3_bind_int(stmt, 4, (int)cJSON_GetNumberValue(kind));
sqlite3_bind_text(stmt, 5, cJSON_GetStringValue(content), -1, SQLITE_STATIC);
sqlite3_bind_text(stmt, 6, cJSON_GetStringValue(sig), -1, SQLITE_STATIC);
// Execute statement
rc = sqlite3_step(stmt);
sqlite3_finalize(stmt);
if (rc != SQLITE_DONE) {
if (rc == SQLITE_CONSTRAINT) {
log_warning("Event already exists in database");
return 0; // Not an error, just duplicate
}
char error_msg[256];
snprintf(error_msg, sizeof(error_msg), "Failed to insert event: %s", sqlite3_errmsg(g_db));
log_error(error_msg);
return -1;
}
// Insert tags if present
if (tags && cJSON_IsArray(tags)) {
const char* event_id = cJSON_GetStringValue(id);
cJSON* tag;
cJSON_ArrayForEach(tag, tags) {
if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
cJSON* tag_name = cJSON_GetArrayItem(tag, 0);
cJSON* tag_value = cJSON_GetArrayItem(tag, 1);
if (cJSON_IsString(tag_name) && cJSON_IsString(tag_value)) {
// Collect additional tag parameters if present
char* parameters = NULL;
if (cJSON_GetArraySize(tag) > 2) {
cJSON* params_array = cJSON_CreateArray();
for (int i = 2; i < cJSON_GetArraySize(tag); i++) {
cJSON_AddItemToArray(params_array, cJSON_Duplicate(cJSON_GetArrayItem(tag, i), 1));
}
parameters = cJSON_Print(params_array);
cJSON_Delete(params_array);
}
const char* tag_sql =
"INSERT INTO tag (id, name, value, parameters) VALUES (?, ?, ?, ?)";
sqlite3_stmt* tag_stmt;
rc = sqlite3_prepare_v2(g_db, tag_sql, -1, &tag_stmt, NULL);
if (rc == SQLITE_OK) {
sqlite3_bind_text(tag_stmt, 1, event_id, -1, SQLITE_STATIC);
sqlite3_bind_text(tag_stmt, 2, cJSON_GetStringValue(tag_name), -1, SQLITE_STATIC);
sqlite3_bind_text(tag_stmt, 3, cJSON_GetStringValue(tag_value), -1, SQLITE_STATIC);
sqlite3_bind_text(tag_stmt, 4, parameters, -1, SQLITE_TRANSIENT);
sqlite3_step(tag_stmt);
sqlite3_finalize(tag_stmt);
}
if (parameters) free(parameters);
}
}
}
}
log_success("Event stored in database");
return 0;
}
// Retrieve event from database
cJSON* retrieve_event(const char* event_id) {
if (!g_db || !event_id) {
return NULL;
}
const char* sql =
"SELECT id, pubkey, created_at, kind, content, sig FROM event WHERE id = ?";
sqlite3_stmt* stmt;
int rc = sqlite3_prepare_v2(g_db, sql, -1, &stmt, NULL);
if (rc != SQLITE_OK) {
return NULL;
}
sqlite3_bind_text(stmt, 1, event_id, -1, SQLITE_STATIC);
cJSON* event = NULL;
if (sqlite3_step(stmt) == SQLITE_ROW) {
event = cJSON_CreateObject();
cJSON_AddStringToObject(event, "id", (char*)sqlite3_column_text(stmt, 0));
cJSON_AddStringToObject(event, "pubkey", (char*)sqlite3_column_text(stmt, 1));
cJSON_AddNumberToObject(event, "created_at", sqlite3_column_int64(stmt, 2));
cJSON_AddNumberToObject(event, "kind", sqlite3_column_int(stmt, 3));
cJSON_AddStringToObject(event, "content", (char*)sqlite3_column_text(stmt, 4));
cJSON_AddStringToObject(event, "sig", (char*)sqlite3_column_text(stmt, 5));
// Add tags array - retrieve from tag table
cJSON* tags_array = cJSON_CreateArray();
const char* tag_sql = "SELECT name, value, parameters FROM tag WHERE id = ?";
sqlite3_stmt* tag_stmt;
if (sqlite3_prepare_v2(g_db, tag_sql, -1, &tag_stmt, NULL) == SQLITE_OK) {
sqlite3_bind_text(tag_stmt, 1, event_id, -1, SQLITE_STATIC);
while (sqlite3_step(tag_stmt) == SQLITE_ROW) {
cJSON* tag = cJSON_CreateArray();
cJSON_AddItemToArray(tag, cJSON_CreateString((char*)sqlite3_column_text(tag_stmt, 0)));
cJSON_AddItemToArray(tag, cJSON_CreateString((char*)sqlite3_column_text(tag_stmt, 1)));
// Add parameters if they exist
const char* parameters = (char*)sqlite3_column_text(tag_stmt, 2);
if (parameters && strlen(parameters) > 0) {
cJSON* params = cJSON_Parse(parameters);
if (params && cJSON_IsArray(params)) {
int param_count = cJSON_GetArraySize(params);
for (int i = 0; i < param_count; i++) {
cJSON* param = cJSON_GetArrayItem(params, i);
cJSON_AddItemToArray(tag, cJSON_Duplicate(param, 1));
}
}
if (params) cJSON_Delete(params);
}
cJSON_AddItemToArray(tags_array, tag);
}
sqlite3_finalize(tag_stmt);
}
cJSON_AddItemToObject(event, "tags", tags_array);
}
sqlite3_finalize(stmt);
return event;
}
// Handle REQ message (subscription)
int handle_req_message(const char* sub_id, cJSON* filters) {
log_info("Handling REQ message");
// For now, just handle simple event ID requests
if (cJSON_IsArray(filters)) {
cJSON* filter = cJSON_GetArrayItem(filters, 0);
if (filter) {
cJSON* ids = cJSON_GetObjectItem(filter, "ids");
if (ids && cJSON_IsArray(ids)) {
cJSON* event_id = cJSON_GetArrayItem(ids, 0);
if (event_id && cJSON_IsString(event_id)) {
cJSON* event = retrieve_event(cJSON_GetStringValue(event_id));
if (event) {
log_success("Found event for subscription");
cJSON_Delete(event);
return 1; // Found event
}
}
}
}
}
return 0; // No events found
}
// Handle EVENT message (publish)
int handle_event_message(cJSON* event) {
log_info("Handling EVENT message");
// Validate event structure (basic check)
cJSON* id = cJSON_GetObjectItem(event, "id");
if (!id || !cJSON_IsString(id)) {
log_error("Invalid event - no ID");
return -1;
}
// Store event in database
if (store_event(event) == 0) {
log_success("Event stored successfully");
return 0;
}
return -1;
}
// Global WebSocket context
static struct lws_context *ws_context = NULL;
// Per-session data structure
struct per_session_data {
int authenticated;
char subscription_id[64];
};
// WebSocket callback function for Nostr relay protocol
static int nostr_relay_callback(struct lws *wsi, enum lws_callback_reasons reason,
void *user, void *in, size_t len) {
struct per_session_data *pss = (struct per_session_data *)user;
switch (reason) {
case LWS_CALLBACK_ESTABLISHED:
log_info("WebSocket connection established");
memset(pss, 0, sizeof(*pss));
break;
case LWS_CALLBACK_RECEIVE:
if (len > 0) {
char *message = malloc(len + 1);
if (message) {
memcpy(message, in, len);
message[len] = '\0';
log_info("Received WebSocket message");
// Parse JSON message
cJSON* json = cJSON_Parse(message);
if (json && cJSON_IsArray(json)) {
// Get message type
cJSON* type = cJSON_GetArrayItem(json, 0);
if (type && cJSON_IsString(type)) {
const char* msg_type = cJSON_GetStringValue(type);
if (strcmp(msg_type, "EVENT") == 0) {
// Handle EVENT message
cJSON* event = cJSON_GetArrayItem(json, 1);
if (event && cJSON_IsObject(event)) {
int result = handle_event_message(event);
// Send OK response
cJSON* event_id = cJSON_GetObjectItem(event, "id");
if (event_id && cJSON_IsString(event_id)) {
cJSON* response = cJSON_CreateArray();
cJSON_AddItemToArray(response, cJSON_CreateString("OK"));
cJSON_AddItemToArray(response, cJSON_CreateString(cJSON_GetStringValue(event_id)));
cJSON_AddItemToArray(response, cJSON_CreateBool(result == 0));
cJSON_AddItemToArray(response, cJSON_CreateString(result == 0 ? "" : "error: failed to store event"));
char *response_str = cJSON_Print(response);
if (response_str) {
size_t response_len = strlen(response_str);
unsigned char *buf = malloc(LWS_PRE + response_len);
if (buf) {
memcpy(buf + LWS_PRE, response_str, response_len);
lws_write(wsi, buf + LWS_PRE, response_len, LWS_WRITE_TEXT);
free(buf);
}
free(response_str);
}
cJSON_Delete(response);
}
}
} else if (strcmp(msg_type, "REQ") == 0) {
// Handle REQ message
cJSON* sub_id = cJSON_GetArrayItem(json, 1);
cJSON* filters = cJSON_GetArrayItem(json, 2);
if (sub_id && cJSON_IsString(sub_id)) {
const char* subscription_id = cJSON_GetStringValue(sub_id);
strncpy(pss->subscription_id, subscription_id, sizeof(pss->subscription_id) - 1);
handle_req_message(subscription_id, filters);
// Send EOSE (End of Stored Events)
cJSON* eose_response = cJSON_CreateArray();
cJSON_AddItemToArray(eose_response, cJSON_CreateString("EOSE"));
cJSON_AddItemToArray(eose_response, cJSON_CreateString(subscription_id));
char *eose_str = cJSON_Print(eose_response);
if (eose_str) {
size_t eose_len = strlen(eose_str);
unsigned char *buf = malloc(LWS_PRE + eose_len);
if (buf) {
memcpy(buf + LWS_PRE, eose_str, eose_len);
lws_write(wsi, buf + LWS_PRE, eose_len, LWS_WRITE_TEXT);
free(buf);
}
free(eose_str);
}
cJSON_Delete(eose_response);
}
} else if (strcmp(msg_type, "CLOSE") == 0) {
// Handle CLOSE message
log_info("Subscription closed");
}
}
}
if (json) cJSON_Delete(json);
free(message);
}
}
break;
case LWS_CALLBACK_CLOSED:
log_info("WebSocket connection closed");
break;
default:
break;
}
return 0;
}
// WebSocket protocol definition
static struct lws_protocols protocols[] = {
{
"nostr-relay-protocol",
nostr_relay_callback,
sizeof(struct per_session_data),
4096, // rx buffer size
0, NULL, 0
},
{ NULL, NULL, 0, 0, 0, NULL, 0 } // terminator
};
// Start libwebsockets-based WebSocket Nostr relay server
int start_websocket_relay() {
struct lws_context_creation_info info;
log_info("Starting libwebsockets-based Nostr relay server...");
memset(&info, 0, sizeof(info));
info.port = DEFAULT_PORT;
info.protocols = protocols;
info.gid = -1;
info.uid = -1;
// Minimal libwebsockets configuration
info.options = LWS_SERVER_OPTION_VALIDATE_UTF8;
// Remove interface restrictions - let system choose
// info.vhost_name = NULL;
// info.iface = NULL;
// Increase max connections for relay usage
info.max_http_header_pool = 16;
info.timeout_secs = 10;
// Max payload size for Nostr events
info.max_http_header_data = 4096;
ws_context = lws_create_context(&info);
if (!ws_context) {
log_error("Failed to create libwebsockets context");
perror("libwebsockets creation error");
return -1;
}
log_success("WebSocket relay started on ws://127.0.0.1:8888");
// Main event loop with proper signal handling
fd_set rfds;
struct timeval tv;
while (g_server_running) {
FD_ZERO(&rfds);
tv.tv_sec = 1;
tv.tv_usec = 0;
int result = lws_service(ws_context, 1000);
if (result < 0) {
log_error("libwebsockets service error");
break;
}
}
log_info("Shutting down WebSocket server...");
lws_context_destroy(ws_context);
ws_context = NULL;
log_success("WebSocket relay shut down cleanly");
return 0;
}
// Print usage information
void print_usage(const char* program_name) {
printf("Usage: %s [OPTIONS]\n", program_name);
printf("\n");
printf("C Nostr Relay Server\n");
printf("\n");
printf("Options:\n");
printf(" -p, --port PORT Listen port (default: %d)\n", DEFAULT_PORT);
printf(" -h, --help Show this help message\n");
printf("\n");
}
int main(int argc, char* argv[]) {
int port = DEFAULT_PORT;
// Parse command line arguments
for (int i = 1; i < argc; i++) {
if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0) {
print_usage(argv[0]);
return 0;
} else if (strcmp(argv[i], "-p") == 0 || strcmp(argv[i], "--port") == 0) {
if (i + 1 < argc) {
port = atoi(argv[++i]);
if (port <= 0 || port > 65535) {
log_error("Invalid port number");
return 1;
}
} else {
log_error("Port argument requires a value");
return 1;
}
} else {
log_error("Unknown argument");
print_usage(argv[0]);
return 1;
}
}
// Set up signal handlers
signal(SIGINT, signal_handler);
signal(SIGTERM, signal_handler);
printf(BLUE BOLD "=== C Nostr Relay Server ===" RESET "\n");
// Initialize database
if (init_database() != 0) {
log_error("Failed to initialize database");
return 1;
}
// Initialize nostr library
if (nostr_init() != 0) {
log_error("Failed to initialize nostr library");
close_database();
return 1;
}
log_info("Starting relay server...");
// Start WebSocket Nostr relay server
int result = start_websocket_relay();
// Cleanup
nostr_cleanup();
close_database();
if (result == 0) {
log_success("Server shutdown complete");
} else {
log_error("Server shutdown with errors");
}
return result;
}