v0.3.1 - Implement database location and extension changes

- Change database extension from .nrdb to .db for standard SQLite convention
- Modify make_and_restart_relay.sh to run executable from build/ directory
- Database files now created in build/ directory alongside executable
- Enhanced --preserve-database flag with backup/restore functionality
- Updated source code references in config.c and main.c
- Port auto-increment functionality remains fully functional

.roo/commands/push.md

@@ -0,0 +1,5 @@
+---
+description: "Brief description of what this command does"
+---
+
+Run build_and_push.sh, and supply a good git commit message.

make_and_restart_relay.sh

@@ -38,7 +38,7 @@ if [ "$HELP" = true ]; then
     echo "Event-Based Configuration:"
     echo "  This relay now uses event-based configuration stored directly in the database."
     echo "  On first startup, keys are automatically generated and printed once."
-    echo "  Database file: <relay_pubkey>.nrdb (created automatically)"
+    echo "  Database file: <relay_pubkey>.db (created automatically)"
     echo ""
     echo "Examples:"
     echo "  $0                       # Fresh start with new keys (default)"
@@ -51,15 +51,22 @@ fi
 
 # Handle database file cleanup for fresh start
 if [ "$PRESERVE_DATABASE" = false ]; then
-    if ls *.nrdb >/dev/null 2>&1; then
+    if ls *.db >/dev/null 2>&1 || ls build/*.db >/dev/null 2>&1; then
         echo "Removing existing database files to trigger fresh key generation..."
-        rm -f *.nrdb
+        rm -f *.db build/*.db
         echo "✓ Database files removed - will generate new keys and database"
     else
         echo "No existing database found - will generate fresh setup"
     fi
 else
     echo "Preserving existing database files as requested"
+    # Back up database files before clean build
+    if ls build/*.db >/dev/null 2>&1; then
+        echo "Backing up existing database files..."
+        mkdir -p /tmp/relay_backup_$$
+        cp build/*.db* /tmp/relay_backup_$$/ 2>/dev/null || true
+        echo "Database files backed up to temporary location"
+    fi
 fi
 
 # Clean up legacy files that are no longer used
@@ -70,6 +77,14 @@ rm -f db/c_nostr_relay.db* 2>/dev/null
 echo "Building project..."
 make clean all
 
+# Restore database files if preserving
+if [ "$PRESERVE_DATABASE" = true ] && [ -d "/tmp/relay_backup_$$" ]; then
+    echo "Restoring preserved database files..."
+    cp /tmp/relay_backup_$$/*.db* build/ 2>/dev/null || true
+    rm -rf /tmp/relay_backup_$$
+    echo "Database files restored to build directory"
+fi
+
 # Check if build was successful
 if [ $? -ne 0 ]; then
     echo "ERROR: Build failed. Cannot restart relay."
@@ -129,9 +144,13 @@ echo "Database will be initialized automatically on startup if needed"
 echo "Starting relay server..."
 echo "Debug: Current processes: $(ps aux | grep 'c_relay_' | grep -v grep || echo 'None')"
 
+# Change to build directory before starting relay so database files are created there
+cd build
 # Start relay in background and capture its PID (no command line arguments needed)
-$BINARY_PATH > relay.log 2>&1 &
+./$(basename $BINARY_PATH) > ../relay.log 2>&1 &
 RELAY_PID=$!
+# Change back to original directory
+cd ..
 
 echo "Started with PID: $RELAY_PID"
 

relay.pid

@@ -1 +1 @@
-1073070
+1177520

relay2.log

@@ -0,0 +1,35 @@
+=== C Nostr Relay Server ===
+Event-based configuration system
+
+[INFO] Existing relay detected
+[INFO] Initializing event-based configuration system...
+[SUCCESS] Event-based configuration system initialized
+[INFO] Starting existing relay...
+  Relay pubkey: 6df436471c7965d6473e89998162e6b87cc3547d71a2db12f559a39f4596059a
+[SUCCESS] Existing relay startup prepared
+[SUCCESS] Database connection established: 6df436471c7965d6473e89998162e6b87cc3547d71a2db12f559a39f4596059a.nrdb
+[INFO] Database schema already exists, skipping initialization
+[INFO] Existing database schema version: 4
+[WARNING] No configuration event found in existing database
+[SUCCESS] Relay information initialized with default values
+[INFO] Initializing NIP-13 Proof of Work configuration
+[INFO] PoW configured in basic validation mode (default)
+[INFO] PoW Configuration: enabled=true, min_difficulty=0, validation_flags=0x1, mode=full
+[INFO] Initializing NIP-40 Expiration Timestamp configuration
+[INFO] Expiration Configuration: enabled=true, strict_mode=true, filter_responses=true, grace_period=300 seconds
+[INFO] Subscription limits: max_per_client=25, max_total=5000
+[INFO] Starting relay server...
+[INFO] Starting libwebsockets-based Nostr relay server...
+[INFO] Checking port availability: 8888
+[WARNING] Port 8888 is in use, trying port 8889 (attempt 2/5)
+[INFO] Checking port availability: 8889
+[INFO] Attempting to bind libwebsockets to port 8889
+[WARNING] WebSocket relay started on ws://127.0.0.1:8889 (configured port 8888 was unavailable)
+[SUCCESS] WebSocket relay started on ws://127.0.0.1:8889 (configured port 8888 was unavailable)
+[INFO] Received shutdown signal
+[INFO] Shutting down WebSocket server...
+[SUCCESS] WebSocket relay shut down cleanly
+[INFO] Cleaning up configuration system...
+[SUCCESS] Configuration system cleaned up
+[INFO] Database connection closed
+[SUCCESS] Server shutdown complete

relay3.log

@@ -0,0 +1,37 @@
+=== C Nostr Relay Server ===
+Event-based configuration system
+
+[INFO] Existing relay detected
+[INFO] Initializing event-based configuration system...
+[SUCCESS] Event-based configuration system initialized
+[INFO] Starting existing relay...
+  Relay pubkey: 6df436471c7965d6473e89998162e6b87cc3547d71a2db12f559a39f4596059a
+[SUCCESS] Existing relay startup prepared
+[SUCCESS] Database connection established: 6df436471c7965d6473e89998162e6b87cc3547d71a2db12f559a39f4596059a.nrdb
+[INFO] Database schema already exists, skipping initialization
+[INFO] Existing database schema version: 4
+[WARNING] No configuration event found in existing database
+[SUCCESS] Relay information initialized with default values
+[INFO] Initializing NIP-13 Proof of Work configuration
+[INFO] PoW configured in basic validation mode (default)
+[INFO] PoW Configuration: enabled=true, min_difficulty=0, validation_flags=0x1, mode=full
+[INFO] Initializing NIP-40 Expiration Timestamp configuration
+[INFO] Expiration Configuration: enabled=true, strict_mode=true, filter_responses=true, grace_period=300 seconds
+[INFO] Subscription limits: max_per_client=25, max_total=5000
+[INFO] Starting relay server...
+[INFO] Starting libwebsockets-based Nostr relay server...
+[INFO] Checking port availability: 8888
+[WARNING] Port 8888 is in use, trying port 8889 (attempt 2/5)
+[INFO] Checking port availability: 8889
+[WARNING] Port 8889 is in use, trying port 8890 (attempt 3/5)
+[INFO] Checking port availability: 8890
+[INFO] Attempting to bind libwebsockets to port 8890
+[WARNING] WebSocket relay started on ws://127.0.0.1:8890 (configured port 8888 was unavailable)
+[SUCCESS] WebSocket relay started on ws://127.0.0.1:8890 (configured port 8888 was unavailable)
+[INFO] Received shutdown signal
+[INFO] Shutting down WebSocket server...
+[SUCCESS] WebSocket relay shut down cleanly
+[INFO] Cleaning up configuration system...
+[SUCCESS] Configuration system cleaned up
+[INFO] Database connection closed
+[SUCCESS] Server shutdown complete

src/config.c

@@ -44,9 +44,9 @@ char** find_existing_nrdb_files(void) {
         return NULL;
     }
     
-    // Count .nrdb files
+    // Count .db files
     while ((entry = readdir(dir)) != NULL) {
-        if (strstr(entry->d_name, ".nrdb") != NULL) {
+        if (strstr(entry->d_name, ".db") != NULL) {
             count++;
         }
     }
@@ -67,7 +67,7 @@ char** find_existing_nrdb_files(void) {
     // Store filenames
     int i = 0;
     while ((entry = readdir(dir)) != NULL && i < count) {
-        if (strstr(entry->d_name, ".nrdb") != NULL) {
+        if (strstr(entry->d_name, ".db") != NULL) {
             files[i] = malloc(strlen(entry->d_name) + 1);
             if (files[i]) {
                 strcpy(files[i], entry->d_name);
@@ -84,8 +84,8 @@ char** find_existing_nrdb_files(void) {
 char* extract_pubkey_from_filename(const char* filename) {
     if (!filename) return NULL;
     
-    // Find .nrdb extension
+    // Find .db extension
-    const char* dot = strstr(filename, ".nrdb");
+    const char* dot = strstr(filename, ".db");
     if (!dot) return NULL;
     
     // Calculate pubkey length
@@ -107,10 +107,10 @@ char* get_database_name_from_relay_pubkey(const char* relay_pubkey) {
         return NULL;
     }
     
-    char* db_name = malloc(strlen(relay_pubkey) + 6);  // +6 for ".nrdb\0"
+    char* db_name = malloc(strlen(relay_pubkey) + 4);  // +4 for ".db\0"
     if (!db_name) return NULL;
 
-    sprintf(db_name, "%s.nrdb", relay_pubkey);
+    sprintf(db_name, "%s.db", relay_pubkey);
     return db_name;
 }
 
@@ -642,6 +642,373 @@ int startup_existing_relay(const char* relay_pubkey) {
     return 0;
 }
 
+// ================================
+// CONFIGURATION FIELD VALIDATION
+// ================================
+
+// Validation helper functions
+static int is_valid_port(const char* port_str) {
+    if (!port_str) return 0;
+    
+    char* endptr;
+    long port = strtol(port_str, &endptr, 10);
+    
+    // Must be valid number and in valid port range
+    return (endptr != port_str && *endptr == '\0' && port >= 1 && port <= 65535);
+}
+
+static int is_valid_boolean(const char* bool_str) {
+    if (!bool_str) return 0;
+    
+    return (strcasecmp(bool_str, "true") == 0 ||
+            strcasecmp(bool_str, "false") == 0 ||
+            strcasecmp(bool_str, "yes") == 0 ||
+            strcasecmp(bool_str, "no") == 0 ||
+            strcasecmp(bool_str, "1") == 0 ||
+            strcasecmp(bool_str, "0") == 0);
+}
+
+static int is_valid_positive_integer(const char* int_str) {
+    if (!int_str) return 0;
+    
+    char* endptr;
+    long val = strtol(int_str, &endptr, 10);
+    
+    return (endptr != int_str && *endptr == '\0' && val >= 0);
+}
+
+static int is_valid_non_negative_integer(const char* int_str) {
+    if (!int_str) return 0;
+    
+    char* endptr;
+    long val = strtol(int_str, &endptr, 10);
+    
+    return (endptr != int_str && *endptr == '\0' && val >= 0);
+}
+
+static int is_valid_string_length(const char* str, size_t max_length) {
+    if (!str) return 1;  // NULL strings are valid (use defaults)
+    return strlen(str) <= max_length;
+}
+
+static int is_valid_pow_mode(const char* mode_str) {
+    if (!mode_str) return 0;
+    
+    return (strcasecmp(mode_str, "basic") == 0 ||
+            strcasecmp(mode_str, "strict") == 0 ||
+            strcasecmp(mode_str, "disabled") == 0);
+}
+
+static int is_valid_hex_key(const char* key_str) {
+    if (!key_str) return 0;
+    
+    // Must be exactly 64 hex characters
+    if (strlen(key_str) != 64) return 0;
+    
+    // Must contain only hex characters
+    for (int i = 0; i < 64; i++) {
+        char c = key_str[i];
+        if (!((c >= '0' && c <= '9') ||
+              (c >= 'a' && c <= 'f') ||
+              (c >= 'A' && c <= 'F'))) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+// Main validation function for configuration fields
+static int validate_config_field(const char* key, const char* value, char* error_msg, size_t error_size) {
+    if (!key || !value) {
+        snprintf(error_msg, error_size, "key or value is NULL");
+        return -1;
+    }
+    
+    // Port validation
+    if (strcmp(key, "relay_port") == 0) {
+        if (!is_valid_port(value)) {
+            snprintf(error_msg, error_size, "invalid port number '%s' (must be 1-65535)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Connection limits
+    if (strcmp(key, "max_connections") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid max_connections '%s' (must be positive integer)", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 1 || val > 10000) {
+            snprintf(error_msg, error_size, "max_connections '%s' out of range (1-10000)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Boolean fields
+    if (strcmp(key, "auth_enabled") == 0 ||
+        strcmp(key, "nip40_expiration_enabled") == 0 ||
+        strcmp(key, "nip40_expiration_strict") == 0 ||
+        strcmp(key, "nip40_expiration_filter") == 0) {
+        if (!is_valid_boolean(value)) {
+            snprintf(error_msg, error_size, "invalid boolean value '%s' for %s", value, key);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // String length validation
+    if (strcmp(key, "relay_description") == 0) {
+        if (!is_valid_string_length(value, RELAY_DESCRIPTION_MAX_LENGTH)) {
+            snprintf(error_msg, error_size, "relay_description too long (max %d characters)", RELAY_DESCRIPTION_MAX_LENGTH);
+            return -1;
+        }
+        return 0;
+    }
+    
+    if (strcmp(key, "relay_contact") == 0) {
+        if (!is_valid_string_length(value, RELAY_CONTACT_MAX_LENGTH)) {
+            snprintf(error_msg, error_size, "relay_contact too long (max %d characters)", RELAY_CONTACT_MAX_LENGTH);
+            return -1;
+        }
+        return 0;
+    }
+    
+    if (strcmp(key, "relay_software") == 0 ||
+        strcmp(key, "relay_version") == 0) {
+        if (!is_valid_string_length(value, 256)) {
+            snprintf(error_msg, error_size, "%s too long (max 256 characters)", key);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // PoW difficulty validation
+    if (strcmp(key, "pow_min_difficulty") == 0) {
+        if (!is_valid_non_negative_integer(value)) {
+            snprintf(error_msg, error_size, "invalid pow_min_difficulty '%s' (must be non-negative integer)", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val > 32) {  // 32 is practically impossible
+            snprintf(error_msg, error_size, "pow_min_difficulty '%s' too high (max 32)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // PoW mode validation
+    if (strcmp(key, "pow_mode") == 0) {
+        if (!is_valid_pow_mode(value)) {
+            snprintf(error_msg, error_size, "invalid pow_mode '%s' (must be basic, strict, or disabled)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Time-based validation
+    if (strcmp(key, "nip40_expiration_grace_period") == 0) {
+        if (!is_valid_non_negative_integer(value)) {
+            snprintf(error_msg, error_size, "invalid grace period '%s' (must be non-negative integer)", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val > 86400) {  // Max 1 day
+            snprintf(error_msg, error_size, "grace period '%s' too long (max 86400 seconds)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Subscription limits
+    if (strcmp(key, "max_subscriptions_per_client") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid max_subscriptions_per_client '%s'", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 1 || val > 1000) {
+            snprintf(error_msg, error_size, "max_subscriptions_per_client '%s' out of range (1-1000)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    if (strcmp(key, "max_total_subscriptions") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid max_total_subscriptions '%s'", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 1 || val > 100000) {
+            snprintf(error_msg, error_size, "max_total_subscriptions '%s' out of range (1-100000)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    if (strcmp(key, "max_filters_per_subscription") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid max_filters_per_subscription '%s'", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 1 || val > 100) {
+            snprintf(error_msg, error_size, "max_filters_per_subscription '%s' out of range (1-100)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Event limits
+    if (strcmp(key, "max_event_tags") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid max_event_tags '%s'", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 1 || val > 1000) {
+            snprintf(error_msg, error_size, "max_event_tags '%s' out of range (1-1000)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    if (strcmp(key, "max_content_length") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid max_content_length '%s'", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 100 || val > 1048576) {  // 1MB max
+            snprintf(error_msg, error_size, "max_content_length '%s' out of range (100-1048576)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    if (strcmp(key, "max_message_length") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid max_message_length '%s'", value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 1024 || val > 1048576) {  // 1KB to 1MB
+            snprintf(error_msg, error_size, "max_message_length '%s' out of range (1024-1048576)", value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Performance limits
+    if (strcmp(key, "default_limit") == 0 || strcmp(key, "max_limit") == 0) {
+        if (!is_valid_positive_integer(value)) {
+            snprintf(error_msg, error_size, "invalid %s '%s'", key, value);
+            return -1;
+        }
+        int val = atoi(value);
+        if (val < 1 || val > 50000) {
+            snprintf(error_msg, error_size, "%s '%s' out of range (1-50000)", key, value);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Key validation for relay keys
+    if (strcmp(key, "relay_pubkey") == 0 || strcmp(key, "relay_privkey") == 0) {
+        if (!is_valid_hex_key(value)) {
+            snprintf(error_msg, error_size, "invalid %s format (must be 64-character hex)", key);
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Special validation for d tag (relay identifier)
+    if (strcmp(key, "d") == 0) {
+        if (!is_valid_hex_key(value)) {
+            snprintf(error_msg, error_size, "invalid relay identifier 'd' format (must be 64-character hex)");
+            return -1;
+        }
+        return 0;
+    }
+    
+    // Unknown field - log warning but allow
+    log_warning("Unknown configuration field");
+    printf("  Field: %s = %s\n", key, value);
+    return 0;
+}
+
+// Validate all fields in a configuration event
+static int validate_configuration_event_fields(const cJSON* event, char* error_msg, size_t error_size) {
+    if (!event) {
+        snprintf(error_msg, error_size, "null configuration event");
+        return -1;
+    }
+    
+    log_info("Validating configuration event fields...");
+    
+    cJSON* tags = cJSON_GetObjectItem(event, "tags");
+    if (!tags || !cJSON_IsArray(tags)) {
+        snprintf(error_msg, error_size, "missing or invalid tags array");
+        return -1;
+    }
+    
+    int validated_fields = 0;
+    int validation_errors = 0;
+    char field_error[512];
+    
+    cJSON* tag = NULL;
+    cJSON_ArrayForEach(tag, tags) {
+        if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
+            cJSON* tag_key = cJSON_GetArrayItem(tag, 0);
+            cJSON* tag_value = cJSON_GetArrayItem(tag, 1);
+            
+            if (tag_key && tag_value &&
+                cJSON_IsString(tag_key) && cJSON_IsString(tag_value)) {
+                
+                const char* key = cJSON_GetStringValue(tag_key);
+                const char* value = cJSON_GetStringValue(tag_value);
+                
+                if (validate_config_field(key, value, field_error, sizeof(field_error)) != 0) {
+                    // Safely truncate the error message if needed
+                    size_t prefix_len = strlen("field validation failed: ");
+                    size_t available_space = error_size > prefix_len ? error_size - prefix_len - 1 : 0;
+                    
+                    if (available_space > 0) {
+                        snprintf(error_msg, error_size, "field validation failed: %.*s",
+                                (int)available_space, field_error);
+                    } else {
+                        strncpy(error_msg, "field validation failed", error_size - 1);
+                        error_msg[error_size - 1] = '\0';
+                    }
+                    
+                    log_error("Configuration field validation failed");
+                    printf("  Field: %s = %s\n", key, value);
+                    printf("  Error: %s\n", field_error);
+                    validation_errors++;
+                    return -1;  // Stop on first error
+                } else {
+                    validated_fields++;
+                }
+            }
+        }
+    }
+    
+    if (validation_errors > 0) {
+        char summary[256];
+        snprintf(summary, sizeof(summary), "%d configuration fields failed validation", validation_errors);
+        log_error(summary);
+        return -1;
+    }
+    
+    char success_msg[256];
+    snprintf(success_msg, sizeof(success_msg), "%d configuration fields validated successfully", validated_fields);
+    log_success(success_msg);
+    return 0;
+}
+
 int process_configuration_event(const cJSON* event) {
     if (!event) {
         log_error("Invalid configuration event");
@@ -690,6 +1057,14 @@ int process_configuration_event(const cJSON* event) {
     
     log_success("Configuration event structure and signature validated successfully");
     
+    // NEW: Validate configuration field values
+    char validation_error[512];
+    if (validate_configuration_event_fields(event, validation_error, sizeof(validation_error)) != 0) {
+        log_error("Configuration field validation failed");
+        printf("  Validation error: %s\n", validation_error);
+        return -1;
+    }
+    
     // Store in database
     if (store_config_event_in_database(event) != 0) {
         log_error("Failed to store configuration event");
@@ -702,7 +1077,7 @@ int process_configuration_event(const cJSON* event) {
         return -1;
     }
     
-    log_success("Configuration event processed successfully");
+    log_success("Configuration event processed successfully with field validation");
     return 0;
 }
 

src/main.c

@@ -10,6 +10,10 @@
 #include <pthread.h>
 #include <sqlite3.h>
 #include <libwebsockets.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
 
 // Include nostr_core_lib for Nostr functionality
 #include "../nostr_core_lib/cjson/cJSON.h"
@@ -2956,6 +2960,34 @@ static struct lws_protocols protocols[] = {
     { NULL, NULL, 0, 0, 0, NULL, 0 } // terminator
 };
 
+// Check if a port is available for binding
+int check_port_available(int port) {
+    int sockfd;
+    struct sockaddr_in addr;
+    int result;
+
+    // Create a socket
+    sockfd = socket(AF_INET, SOCK_STREAM, 0);
+    if (sockfd < 0) {
+        return 0; // Cannot create socket, assume port unavailable
+    }
+
+    // Set up the address structure
+    memset(&addr, 0, sizeof(addr));
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = INADDR_ANY;
+    addr.sin_port = htons(port);
+
+    // Try to bind to the port
+    result = bind(sockfd, (struct sockaddr*)&addr, sizeof(addr));
+    
+    // Close the socket
+    close(sockfd);
+
+    // Return 1 if bind succeeded (port available), 0 if failed (port in use)
+    return (result == 0) ? 1 : 0;
+}
+
 // Start libwebsockets-based WebSocket Nostr relay server
 int start_websocket_relay(int port_override) {
     struct lws_context_creation_info info;
@@ -2964,12 +2996,15 @@ int start_websocket_relay(int port_override) {
 
     memset(&info, 0, sizeof(info));
     // Use port override if provided, otherwise use configuration
-    info.port = (port_override > 0) ? port_override : get_config_int("relay_port", DEFAULT_PORT);
+    int configured_port = (port_override > 0) ? port_override : get_config_int("relay_port", DEFAULT_PORT);
+    int actual_port = configured_port;
+    int port_attempts = 0;
+    const int max_port_attempts = 5;
+
+    // Minimal libwebsockets configuration
     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
@@ -2983,15 +3018,82 @@ int start_websocket_relay(int port_override) {
     // Max payload size for Nostr events
     info.max_http_header_data = 4096;
 
-    ws_context = lws_create_context(&info);
+    // Find an available port with pre-checking
+    while (port_attempts < max_port_attempts) {
+        char attempt_msg[256];
+        snprintf(attempt_msg, sizeof(attempt_msg), "Checking port availability: %d", actual_port);
+        log_info(attempt_msg);
+        
+        // Pre-check if port is available
+        if (!check_port_available(actual_port)) {
+            port_attempts++;
+            if (port_attempts < max_port_attempts) {
+                char retry_msg[256];
+                snprintf(retry_msg, sizeof(retry_msg), "Port %d is in use, trying port %d (attempt %d/%d)",
+                         actual_port, actual_port + 1, port_attempts + 1, max_port_attempts);
+                log_warning(retry_msg);
+                actual_port++;
+                continue;
+            } else {
+                char error_msg[512];
+                snprintf(error_msg, sizeof(error_msg),
+                         "Failed to find available port after %d attempts (tried ports %d-%d)",
+                         max_port_attempts, configured_port, actual_port);
+                log_error(error_msg);
+                return -1;
+            }
+        }
+        
+        // Port appears available, try creating libwebsockets context
+        info.port = actual_port;
+        
+        char binding_msg[256];
+        snprintf(binding_msg, sizeof(binding_msg), "Attempting to bind libwebsockets to port %d", actual_port);
+        log_info(binding_msg);
+        
+        ws_context = lws_create_context(&info);
+        if (ws_context) {
+            // Success! Port binding worked
+            break;
+        }
+        
+        // libwebsockets failed even though port check passed
+        // This could be due to timing or different socket options
+        int errno_saved = errno;
+        char lws_error_msg[256];
+        snprintf(lws_error_msg, sizeof(lws_error_msg),
+                 "libwebsockets failed to bind to port %d (errno: %d)", actual_port, errno_saved);
+        log_warning(lws_error_msg);
+        
+        port_attempts++;
+        if (port_attempts < max_port_attempts) {
+            actual_port++;
+            continue;
+        }
+        
+        // If we get here, we've exhausted attempts
+        break;
+    }
+
     if (!ws_context) {
-        log_error("Failed to create libwebsockets context");
+        char error_msg[512];
+        snprintf(error_msg, sizeof(error_msg),
+                 "Failed to create libwebsockets context after %d attempts. Last attempted port: %d",
+                 port_attempts, actual_port);
+        log_error(error_msg);
         perror("libwebsockets creation error");
         return -1;
     }
 
     char startup_msg[256];
-    snprintf(startup_msg, sizeof(startup_msg), "WebSocket relay started on ws://127.0.0.1:%d", info.port);
+    if (actual_port != configured_port) {
+        snprintf(startup_msg, sizeof(startup_msg),
+                 "WebSocket relay started on ws://127.0.0.1:%d (configured port %d was unavailable)",
+                 actual_port, configured_port);
+        log_warning(startup_msg);
+    } else {
+        snprintf(startup_msg, sizeof(startup_msg), "WebSocket relay started on ws://127.0.0.1:%d", actual_port);
+    }
     log_success(startup_msg);
 
     // Main event loop with proper signal handling
@@ -3034,7 +3136,7 @@ void print_usage(const char* program_name) {
     printf("Configuration:\n");
     printf("  This relay uses event-based configuration stored in the database.\n");
     printf("  On first startup, keys are automatically generated and printed once.\n");
-    printf("  Database file: <relay_pubkey>.nrdb (created automatically)\n");
+    printf("  Database file: <relay_pubkey>.db (created automatically)\n");
     printf("\n");
     printf("Examples:\n");
     printf("  %s                       # Start relay (auto-configure on first run)\n", program_name);

test_port_increment.log

@@ -0,0 +1,47 @@
+=== C Nostr Relay Server ===
+Event-based configuration system
+
+[INFO] Existing relay detected
+[INFO] Initializing event-based configuration system...
+[SUCCESS] Event-based configuration system initialized
+[INFO] Starting existing relay...
+  Relay pubkey: 6df436471c7965d6473e89998162e6b87cc3547d71a2db12f559a39f4596059a
+[SUCCESS] Existing relay startup prepared
+[SUCCESS] Database connection established: 6df436471c7965d6473e89998162e6b87cc3547d71a2db12f559a39f4596059a.nrdb
+[INFO] Database schema already exists, skipping initialization
+[INFO] Existing database schema version: 4
+[INFO] Applying configuration from event...
+[INFO] Checking for runtime configuration changes...
+[INFO] Subscription limits changed - updating subscription manager
+[INFO] Subscription limits: max_per_client=25, max_total=5000
+[INFO] PoW configuration changed - reinitializing PoW system
+[INFO] Initializing NIP-13 Proof of Work configuration
+[INFO] PoW configured in basic validation mode
+[INFO] PoW Configuration: enabled=true, min_difficulty=0, validation_flags=0x1, mode=full
+[INFO] Expiration configuration changed - reinitializing expiration system
+[INFO] Initializing NIP-40 Expiration Timestamp configuration
+[INFO] Expiration Configuration: enabled=true, strict_mode=true, filter_responses=true, grace_period=300 seconds
+[INFO] Relay information changed - reinitializing relay info
+[SUCCESS] Relay information initialized with default values
+[SUCCESS] Configuration updated via kind 33334 event - 4 system components reinitialized
+[SUCCESS] Configuration applied from event (4 handlers executed)
+[SUCCESS] Configuration loaded from database
+[SUCCESS] Relay information initialized with default values
+[INFO] Initializing NIP-13 Proof of Work configuration
+[INFO] PoW configured in basic validation mode
+[INFO] PoW Configuration: enabled=true, min_difficulty=0, validation_flags=0x1, mode=full
+[INFO] Initializing NIP-40 Expiration Timestamp configuration
+[INFO] Expiration Configuration: enabled=true, strict_mode=true, filter_responses=true, grace_period=300 seconds
+[INFO] Subscription limits: max_per_client=25, max_total=5000
+[INFO] Starting relay server...
+[INFO] Starting libwebsockets-based Nostr relay server...
+[INFO] Attempting to bind to port 8888
+[2025/09/06 20:34:16:8170] E: ERROR on binding fd 8 to port 8888 (-1 98)
+[2025/09/06 20:34:16:8172] E: init server failed
+[2025/09/06 20:34:16:8172] E: Failed to create default vhost
+[ERROR] Failed to create libwebsockets context after 1 attempts. Last attempted port: 8888
+libwebsockets creation error: Inappropriate ioctl for device
+[INFO] Cleaning up configuration system...
+[SUCCESS] Configuration system cleaned up
+[INFO] Database connection closed
+[ERROR] Server shutdown with errors