utun2/!/config_parser.c

// config_parser.c - Configuration parser for utun application (updated for new structures)
#define _POSIX_C_SOURCE 200809L
#include "config_parser.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "../lib/debug_config.h"
#include <ctype.h>
#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <ifaddrs.h>
#include <net/if.h>

#define MAX_LINE_LEN 1024
#define INITIAL_ARRAY_CAPACITY 8

typedef enum {
    SECTION_UNKNOWN,
    SECTION_GLOBAL,
    SECTION_SERVER,
    SECTION_CLIENT,
    SECTION_ROUTING
} section_type_t;

static char* trim(char *str) {
    if (!str) return NULL;
    while (isspace((unsigned char)*str)) str++;
    char *end = str + strlen(str) - 1;
    while (end > str && isspace((unsigned char)*end)) end--;
    *(end + 1) = '\0';
    return str;
}

static int parse_key_value(const char *line, char *key, size_t key_len, char *value, size_t value_len) {
    char *equal = strchr(line, '=');
    if (!equal) return -1;
    
    size_t key_size = equal - line;
    if (key_size >= key_len) return -1;
    strncpy(key, line, key_size);
    key[key_size] = '\0';
    trim(key);
    
    const char *val_start = equal + 1;
    size_t val_len = strlen(val_start);
    if (val_len >= value_len) return -1;
    strcpy(value, val_start);
    trim(value);
    
    return 0;
}

static int assign_string(char *dest, size_t dest_size, const char *src) {
    if (!dest || !src || strlen(src) >= dest_size) return -1;
    strcpy(dest, src);
    return 0;
}

static int parse_ip_with_netmask(const char *str, struct IP *ip, uint8_t *netmask) {
    char ip_str[64];
    strncpy(ip_str, str, sizeof(ip_str) - 1);
    ip_str[sizeof(ip_str) - 1] = '\0';
    
    char *slash = strchr(ip_str, '/');
    if (slash) {
        *slash = '\0';
        *netmask = atoi(slash + 1);
    } else {
        *netmask = 32; // Default IPv4 netmask
    }
    
    // Try IPv4 first
    struct in_addr addr4;
    if (inet_pton(AF_INET, ip_str, &addr4) == 1) {
        ip->family = AF_INET;
        ip->addr.v4 = addr4;
        return 0;
    }
    
    // Try IPv6
    struct in6_addr addr6;
    if (inet_pton(AF_INET6, ip_str, &addr6) == 1) {
        ip->family = AF_INET6;
        ip->addr.v6 = addr6;
        if (*netmask == 32) *netmask = 128; // Default IPv6 netmask
        return 0;
    }
    
    DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "parse_ip_with_netmask: invalid IP address format: %s", str);
    return -1;
}

static int parse_sockaddr(const char *addr_str, const char *port_str, struct sockaddr_storage *sockaddr) {
    struct addrinfo hints = {0};
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_DGRAM;
    
    struct addrinfo *result;
    if (getaddrinfo(addr_str, port_str, &hints, &result) != 0) {
        return -1;
    }
    
    memcpy(sockaddr, result->ai_addr, result->ai_addrlen);
    freeaddrinfo(result);
    return 0;
}

static int parse_address_and_port(const char *str, struct sockaddr_storage *sockaddr) {
    char addr_copy[MAX_ADDR_LEN];
    if (strlen(str) >= sizeof(addr_copy)) return -1;
    strcpy(addr_copy, str);
    
    char *port_str = strrchr(addr_copy, ':');
    if (!port_str) return -1;
    
    *port_str = '\0';
    port_str++;
    
    return parse_sockaddr(addr_copy, port_str, sockaddr);
}

static uint32_t get_netif_index(const char *ifname) {
    if (!ifname || strlen(ifname) == 0) return 0;
    return if_nametoindex(ifname);
}

static struct CFG_CLIENT_LINK* create_client_link(struct CFG_SERVER* local_srv, const char *remote_addr) {
    struct CFG_CLIENT_LINK *link = calloc(1, sizeof(struct CFG_CLIENT_LINK));
    if (!link) {
        DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "create_client_link: failed to allocate memory for client link");
        return NULL;
    }
    
    link->local_srv = local_srv;
    
    if (parse_address_and_port(remote_addr, &link->remote_addr) < 0) {
        free(link);
        return NULL;
    }
    
    link->next = NULL;
    return link;
}

static void free_cfg_client_links(struct CFG_CLIENT_LINK *links) {
    while (links) {
        struct CFG_CLIENT_LINK *next = links->next;
        free(links);
        links = next;
    }
}

static struct CFG_ROUTE_ENTRY* create_route_entry(const char *subnet_str) {
    struct CFG_ROUTE_ENTRY *entry = calloc(1, sizeof(struct CFG_ROUTE_ENTRY));
    if (!entry) {
        DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "create_route_entry: failed to allocate memory for route entry");
        return NULL;
    }
    
    if (parse_ip_with_netmask(subnet_str, &entry->ip, &entry->netmask) < 0) {
        free(entry);
        return NULL;
    }
    
    entry->next = NULL;
    return entry;
}

static void free_route_entries(struct CFG_ROUTE_ENTRY *entries) {
    while (entries) {
        struct CFG_ROUTE_ENTRY *next = entries->next;
        free(entries);
        entries = next;
    }
}

static int add_route_entry(struct CFG_ROUTE_ENTRY **list, const char *subnet_str) {
    struct CFG_ROUTE_ENTRY *new_entry = create_route_entry(subnet_str);
    if (!new_entry) return -1;
    
    // Add to head of list
    new_entry->next = *list;
    *list = new_entry;
    return 0;
}

static struct CFG_SERVER* find_server_by_name(struct CFG_SERVER *servers, const char *name) {
    struct CFG_SERVER *srv = servers;
    while (srv) {
        if (strcmp(srv->name, name) == 0) {
            return srv;
        }
        srv = srv->next;
    }
    return NULL;
}

static int parse_global(const char *key, const char *value, struct global_config *global) {
    if (strcmp(key, "my_private_key") == 0) {
        return assign_string(global->my_private_key_hex, MAX_KEY_LEN, value);
    }
    if (strcmp(key, "my_public_key") == 0) {
        return assign_string(global->my_public_key_hex, MAX_KEY_LEN, value);
    }
    if (strcmp(key, "my_node_id") == 0) { 
        global->my_node_id = strtoull(value, NULL, 16);
        return 0;
    }
    if (strcmp(key, "tun_ifname") == 0) {
        snprintf(global->tun_ifname, sizeof(global->tun_ifname), "%s", value);
        return 0;
    }
    if (strcmp(key, "tun_ip") == 0) {
        uint8_t netmask;
        return parse_ip_with_netmask(value, &global->tun_ip, &netmask);
    }
    if (strcmp(key, "mtu") == 0) {
        global->mtu = atoi(value);
        return 0;
    }
    if (strcmp(key, "control_ip") == 0) {
        // Store for later processing with control_port
        return 0; // We'll handle this when we see control_port
    }
    if (strcmp(key, "control_port") == 0) {
        // This is tricky - we need to get control_ip from previous parsing
        // For now, we'll use a simple approach
        struct global_config temp_global = *global;
        // Assume we stored control_ip somewhere or use default
        char control_ip[MAX_ADDR_LEN] = "127.0.0.1"; // Default
        char port_str[16];
        snprintf(port_str, sizeof(port_str), "%s", value);
        parse_sockaddr(control_ip, port_str, &global->control_sock);
        return 0;
    }
    if (strcmp(key, "net_debug") == 0) {
        global->net_debug = atoi(value);
        return 0;
    }
    return 0;
}

static int parse_server(const char *key, const char *value, struct CFG_SERVER *srv) {
    if (strcmp(key, "addr") == 0) {
        return parse_address_and_port(value, &srv->ip);
    }
    if (strcmp(key, "so_mark") == 0) {
        srv->so_mark = atoi(value);
        return 0;
    }
    if (strcmp(key, "netif") == 0) {
        srv->netif_index = get_netif_index(value);
        return 0;
    }
    if (strcmp(key, "type") == 0) {
        if (strcmp(value, "public") == 0) {
            srv->type = CFG_SERVER_TYPE_PUBLIC;
        } else if (strcmp(value, "nat") == 0) {
            srv->type = CFG_SERVER_TYPE_NAT;
        } else if (strcmp(value, "private") == 0) {
            srv->type = CFG_SERVER_TYPE_PRIVATE;
        } else {
            srv->type = CFG_SERVER_TYPE_UNKNOWN;
        }
        return 0;
    }
    return 0;
}

static int parse_client(const char *key, const char *value, struct CFG_CLIENT *cli, struct CFG_SERVER *servers) {
    if (strcmp(key, "link") == 0) {
        char link_copy[MAX_CONN_NAME_LEN + MAX_ADDR_LEN];
        if (strlen(value) >= sizeof(link_copy)) return -1;
        strcpy(link_copy, value);
        
        // Find first colon (separator between server and ip:port)
        char *first_colon = strchr(link_copy, ':');
        if (!first_colon) return -1;
        
        *first_colon = '\0';
        
        // Find server by name
        struct CFG_SERVER *local_srv = find_server_by_name(servers, link_copy);
        if (!local_srv) {
            DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "parse_client: server '%s' not found for client link", link_copy);
            return -1;
        }
        
        struct CFG_CLIENT_LINK *new_link = create_client_link(local_srv, first_colon + 1);
        if (!new_link) return -1;
        
        // Add to linked list (prepend)
        new_link->next = cli->links;
        cli->links = new_link;
        
        return 0;
    }
    
    if (strcmp(key, "peer_public_key") == 0) {
        return assign_string(cli->peer_public_key_hex, MAX_KEY_LEN, value);
    }
    
    if (strcmp(key, "keepalive") == 0) {
        cli->keepalive = atoi(value);
        return 0;
    }
    
    return 0;
}

static section_type_t parse_section_header(const char *line, char *name, size_t name_len) {
    if (line[0] != '[') return SECTION_UNKNOWN;
    
    size_t line_len = strlen(line);
    if (line[line_len - 1] != ']') return SECTION_UNKNOWN;
    
    char section[128];
    if (line_len - 2 >= sizeof(section)) return SECTION_UNKNOWN;
    
    strncpy(section, line + 1, line_len - 2);
    section[line_len - 2] = '\0';
    trim(section);
    
    if (strcasecmp(section, "global") == 0) return SECTION_GLOBAL;
    if (strcasecmp(section, "routing") == 0) return SECTION_ROUTING;
    
    char *colon = strchr(section, ':');
    if (!colon) return SECTION_UNKNOWN;
    
    *colon = '\0';
    char *type = trim(section);
    char *n = trim(colon + 1);
    
    if (strlen(n) >= name_len) return SECTION_UNKNOWN;
    strcpy(name, n);
    
    if (strcasecmp(type, "server") == 0) return SECTION_SERVER;
    if (strcasecmp(type, "client") == 0) return SECTION_CLIENT;
    
    return SECTION_UNKNOWN;
}

static struct utun_config* parse_config_internal(FILE *fp, const char *filename) {
    struct utun_config *cfg = calloc(1, sizeof(struct utun_config));
    if (!cfg) {
        DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "parse_config_internal: failed to allocate memory for config structure");
        return NULL;
    }
    
    section_type_t cur_section = SECTION_UNKNOWN;
    struct CFG_SERVER *cur_server = NULL;
    struct CFG_CLIENT *cur_client = NULL;
    char line[MAX_LINE_LEN];
    int line_num = 0;
    
    while (fgets(line, sizeof(line), fp)) {
        line_num++;
        char *trimmed = trim(line);
        
        if (trimmed[0] == '\0' || trimmed[0] == '#') continue;
        
        if (trimmed[0] == '[') {
            // Handle previous section
            if (cur_section == SECTION_SERVER && cur_server) {
                // Add server to linked list
                cur_server->next = cfg->servers;
                cfg->servers = cur_server;
                cur_server = NULL;
            }
            if (cur_section == SECTION_CLIENT && cur_client) {
                // Add client to linked list
                cur_client->next = cfg->clients;
                cfg->clients = cur_client;
                cur_client = NULL;
            }
            
            char name[MAX_CONN_NAME_LEN];
            cur_section = parse_section_header(trimmed, name, sizeof(name));
            
            if (cur_section == SECTION_SERVER) {
                cur_server = calloc(1, sizeof(struct CFG_SERVER));
                if (!cur_server) {
                    DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "parse_config_internal: failed to allocate memory for server %s", name);
                    goto error;
                }
                strcpy(cur_server->name, name);
            } else if (cur_section == SECTION_CLIENT) {
                cur_client = calloc(1, sizeof(struct CFG_CLIENT));
                if (!cur_client) {
                    DEBUG_ERROR(DEBUG_CATEGORY_MEMORY, "parse_config_internal: failed to allocate memory for client %s", name);
                    goto error;
                }
                strcpy(cur_client->name, name);
            }
            continue;
        }
        
        char key[MAX_LINE_LEN], value[MAX_LINE_LEN];
        if (parse_key_value(trimmed, key, sizeof(key), value, sizeof(value)) < 0) {
            printf( "%s:%d: Invalid key=value format", filename, line_num);
            continue;
        }
        
        switch (cur_section) {
            case SECTION_GLOBAL:
                if (parse_global(key, value, &cfg->global) < 0) {
                    printf( "%s:%d: Invalid global key '%s'", filename, line_num, key);
                }
                break;
            case SECTION_SERVER:
                if (cur_server && parse_server(key, value, cur_server) < 0) {
                    printf( "%s:%d: Invalid server key '%s'", filename, line_num, key);
                }
                break;
            case SECTION_CLIENT:
                if (cur_client && parse_client(key, value, cur_client, cfg->servers) < 0) {
                    printf( "%s:%d: Invalid client key '%s'", filename, line_num, key);
                }
                break;
            case SECTION_ROUTING:
                if (strcmp(key, "allowed_subnet") == 0) {
                    add_route_entry(&cfg->allowed_subnets, value);
                } else if (strcmp(key, "my_subnet") == 0) {
                    add_route_entry(&cfg->my_subnets, value);
                }
                break;
            default:
                printf( "%s:%d: Key outside section: %s", filename, line_num, key);
                break;
        }
    }
    
    // Handle final sections
    if (cur_section == SECTION_SERVER && cur_server) {
        cur_server->next = cfg->servers;
        cfg->servers = cur_server;
    }
    if (cur_section == SECTION_CLIENT && cur_client) {
        cur_client->next = cfg->clients;
        cfg->clients = cur_client;
    }
    
    // Set default TUN interface name if not provided
    if (cfg->global.tun_ifname[0] == '\0') {
        snprintf(cfg->global.tun_ifname, sizeof(cfg->global.tun_ifname), "tun0");
        DEBUG_INFO(DEBUG_CATEGORY_CONFIG, "Auto-generated TUN interface name: %s", cfg->global.tun_ifname);
    }
    
    return cfg;
    
error:
    if (cur_server) free(cur_server);
    if (cur_client) {
        free_cfg_client_links(cur_client->links);
        free(cur_client);
    }
    free_config(cfg);
    return NULL;
}

struct utun_config* parse_config(const char *filename) {
    printf("[CONFIG DEBUG] Opening config file: %s\n", filename);
    FILE *fp = fopen(filename, "r");
    if (!fp) {
        printf("[CONFIG ERROR] Failed to open config file: %s (errno=%d)\n", filename, errno);
        return NULL;
    }
    
    printf("[CONFIG DEBUG] Successfully opened config file\n");
    struct utun_config *config = parse_config_internal(fp, filename);
    fclose(fp);
    return config;
}

void free_config(struct utun_config *config) {
    if (!config) return;
    
    // Free servers
    struct CFG_SERVER *server = config->servers;
    while (server) {
        struct CFG_SERVER *next = server->next;
        free(server);
        server = next;
    }
    
    // Free clients and their links
    struct CFG_CLIENT *client = config->clients;
    while (client) {
        struct CFG_CLIENT *next = client->next;
        free_cfg_client_links(client->links);
        free(client);
        client = next;
    }
    
    // Free route entries
    free_route_entries(config->allowed_subnets);
    free_route_entries(config->my_subnets);
    
    free(config);
}

static const char* ip_to_string(const struct IP *ip, char *buffer, size_t buffer_size) {
    if (ip->family == AF_INET) {
        inet_ntop(AF_INET, &ip->addr.v4, buffer, buffer_size);
    } else if (ip->family == AF_INET6) {
        inet_ntop(AF_INET6, &ip->addr.v6, buffer, buffer_size);
    } else {
        snprintf(buffer, buffer_size, "invalid");
    }
    return buffer;
}

void print_config(const struct utun_config *cfg) {
    if (!cfg) return;
    
    const struct global_config *g = &cfg->global;
    char ip_buffer[64];
    
    printf("Global:\n");
    printf("  Private key: %s\n", g->my_private_key_hex);
    printf("  Public key: %s\n", g->my_public_key_hex);
    printf("  Node ID: %llx\n", (unsigned long long)g->my_node_id);
    printf("  TUN interface: %s\n", g->tun_ifname[0] ? g->tun_ifname : "auto");
    printf("  TUN IP: %s\n", ip_to_string(&g->tun_ip, ip_buffer, sizeof(ip_buffer)));
    printf("  MTU: %d\n", g->mtu);
    printf("  Net debug: %d\n", g->net_debug);
    
    printf("\nServers:\n");
    struct CFG_SERVER *s = cfg->servers;
    while (s) {
        char addr_buffer[64];
        struct sockaddr_in *sin = (struct sockaddr_in *)&s->ip;
        inet_ntop(AF_INET, &sin->sin_addr, addr_buffer, sizeof(addr_buffer));
        printf("  %s: %s:%d (mark=%d, netif=%u, type=%u)\n", 
               s->name, addr_buffer, ntohs(sin->sin_port), 
               s->so_mark, s->netif_index, s->type);
        s = s->next;
    }
    
    printf("\nClients:\n");
    struct CFG_CLIENT *c = cfg->clients;
    while (c) {
        printf("  %s:\n", c->name);
        struct CFG_CLIENT_LINK *link = c->links;
        int link_num = 1;
        while (link) {
            char addr_buffer[64];
            struct sockaddr_in *sin = (struct sockaddr_in *)&link->remote_addr;
            inet_ntop(AF_INET, &sin->sin_addr, addr_buffer, sizeof(addr_buffer));
            printf("    Link %d: %s:%d (via %s)\n", link_num++, addr_buffer, ntohs(sin->sin_port), link->local_srv->name);
            link = link->next;
        }
        printf("    Peer key: %s\n", c->peer_public_key_hex);
        printf("    Keepalive: %d\n", c->keepalive);
        c = c->next;
    }
    
    printf("\nAllowed Subnets:\n");
    struct CFG_ROUTE_ENTRY *allowed = cfg->allowed_subnets;
    while (allowed) {
        printf("  %s/%d\n", ip_to_string(&allowed->ip, ip_buffer, sizeof(ip_buffer)), allowed->netmask);
        allowed = allowed->next;
    }
    
    printf("\nMy Subnets:\n");
    struct CFG_ROUTE_ENTRY *my = cfg->my_subnets;
    while (my) {
        printf("  %s/%d\n", ip_to_string(&my->ip, ip_buffer, sizeof(ip_buffer)), my->netmask);
        my = my->next;
    }
}

int update_config_keys(const char *filename, const char *priv_key, const char *pub_key) {
    // Minimal implementation: just append to file
    FILE *fp = fopen(filename, "a");
    if (!fp) return -1;
    
    fprintf(fp, "\n[global]\n");
    fprintf(fp, "my_private_key=%s\n", priv_key);
    fprintf(fp, "my_public_key=%s\n", pub_key);
    
    fclose(fp);
    return 0;
}