root/trunk/wifidog/src/util.c

/********************************************************************\
 * This program is free software; you can redistribute it and/or    *
 * modify it under the terms of the GNU General Public License as   *
 * published by the Free Software Foundation; either version 2 of   *
 * the License, or (at your option) any later version.              *
 *                                                                  *
 * This program is distributed in the hope that it will be useful,  *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    *
 * GNU General Public License for more details.                     *
 *                                                                  *
 * You should have received a copy of the GNU General Public License*
 * along with this program; if not, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 59 Temple Place - Suite 330        Fax:    +1-617-542-2652       *
 * Boston, MA  02111-1307,  USA       gnu@gnu.org                   *
 *                                                                  *
 \********************************************************************/

/*
 * $Id$
 */
/**
  @file util.c
  @brief Misc utility functions
  @author Copyright (C) 2004 Philippe April <papril777@yahoo.com>
  @author Copyright (C) 2006 Benoit Grégoire <bock@step.polymtl.ca>
 */

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <errno.h>
#include <pthread.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/unistd.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <arpa/inet.h>

#if defined(__NetBSD__)
#include <sys/socket.h>
#include <ifaddrs.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <util.h>
#endif

#ifdef __linux__
#include <netinet/in.h>
#include <net/if.h>
#endif

#include <string.h>
#include <pthread.h>
#include <netdb.h>

#include "common.h"
#include "client_list.h"
#include "safe.h"
#include "util.h"
#include "conf.h"
#include "debug.h"

#include "../config.h"

static pthread_mutex_t ghbn_mutex = PTHREAD_MUTEX_INITIALIZER;

/* Defined in ping_thread.c */
extern time_t started_time;

/* Defined in clientlist.c */
extern  pthread_mutex_t client_list_mutex;
extern  pthread_mutex_t config_mutex;

/* Defined in commandline.c */
extern pid_t restart_orig_pid;

/* XXX Do these need to be locked ? */
static time_t last_online_time = 0;
static time_t last_offline_time = 0;
static time_t last_auth_online_time = 0;
static time_t last_auth_offline_time = 0;

long served_this_session = 0;

/** Fork a child and execute a shell command, the parent
 * process waits for the child to return and returns the child's exit()
 * value.
 * @return Return code of the command
 */
int
execute(char *cmd_line, int quiet)
{
        int pid,
            status,
            rc;

        const char *new_argv[4];
        new_argv[0] = "/bin/sh";
        new_argv[1] = "-c";
        new_argv[2] = cmd_line;
        new_argv[3] = NULL;

        pid = safe_fork();
        if (pid == 0) {    /* for the child process:         */
                /* We don't want to see any errors if quiet flag is on */
                if (quiet) close(2);
                if (execvp("/bin/sh", (char *const *)new_argv) == -1) {    /* execute the command  */
                        debug(LOG_ERR, "execvp(): %s", strerror(errno));
                } else {
                        debug(LOG_ERR, "execvp() failed");
                }
                exit(1);
        }

        /* for the parent:      */
        debug(LOG_DEBUG, "Waiting for PID %d to exit", pid);
        rc = waitpid(pid, &status, 0);
        debug(LOG_DEBUG, "Process PID %d exited", rc);

        return (WEXITSTATUS(status));
}

        struct in_addr *
wd_gethostbyname(const char *name)
{
        struct hostent *he;
        struct in_addr *h_addr, *in_addr_temp;

        /* XXX Calling function is reponsible for free() */

        h_addr = safe_malloc(sizeof(struct in_addr));

        LOCK_GHBN();

        he = gethostbyname(name);

        if (he == NULL) {
                free(h_addr);
                UNLOCK_GHBN();
                return NULL;
        }

        mark_online();

        in_addr_temp = (struct in_addr *)he->h_addr_list[0];
        h_addr->s_addr = in_addr_temp->s_addr;

        UNLOCK_GHBN();

        return h_addr;
}

        char *
get_iface_ip(const char *ifname)
{
#if defined(__linux__)
        struct ifreq if_data;
        struct in_addr in;
        char *ip_str;
        int sockd;
        u_int32_t ip;

        /* Create a socket */
        if ((sockd = socket (AF_INET, SOCK_PACKET, htons(0x8086))) < 0) {
                debug(LOG_ERR, "socket(): %s", strerror(errno));
                return NULL;
        }

        /* Get IP of internal interface */
        strcpy (if_data.ifr_name, ifname);

        /* Get the IP address */
        if (ioctl (sockd, SIOCGIFADDR, &if_data) < 0) {
                debug(LOG_ERR, "ioctl(): SIOCGIFADDR %s", strerror(errno));
                return NULL;
        }
        memcpy ((void *) &ip, (void *) &if_data.ifr_addr.sa_data + 2, 4);
        in.s_addr = ip;

        ip_str = inet_ntoa(in);
        close(sockd);
        return safe_strdup(ip_str);
#elif defined(__NetBSD__)
        struct ifaddrs *ifa, *ifap;
        char *str = NULL;

        if (getifaddrs(&ifap) == -1) {
                debug(LOG_ERR, "getifaddrs(): %s", strerror(errno));
                return NULL;
        }
        /* XXX arbitrarily pick the first IPv4 address */
        for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
                if (strcmp(ifa->ifa_name, ifname) == 0 &&
                                ifa->ifa_addr->sa_family == AF_INET)
                        break;
        }
        if (ifa == NULL) {
                debug(LOG_ERR, "%s: no IPv4 address assigned");
                goto out;
        }
        str = safe_strdup(inet_ntoa(
                                ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr));
out:
        freeifaddrs(ifap);
        return str;
#else
        return safe_strdup("0.0.0.0");
#endif
}

        char *
get_iface_mac(const char *ifname)
{
#if defined(__linux__)
        int r, s;
        struct ifreq ifr;
        char *hwaddr, mac[13];

        strcpy(ifr.ifr_name, ifname);

        s = socket(PF_INET, SOCK_DGRAM, 0);
        if (-1 == s) {
                debug(LOG_ERR, "get_iface_mac socket: %s", strerror(errno));
                return NULL;
        }

        r = ioctl(s, SIOCGIFHWADDR, &ifr);
        if (r == -1) {
                debug(LOG_ERR, "get_iface_mac ioctl(SIOCGIFHWADDR): %s", strerror(errno));
                close(s);
                return NULL;
        }

        hwaddr = ifr.ifr_hwaddr.sa_data;
        close(s);
        snprintf(mac, sizeof(mac), "%02X%02X%02X%02X%02X%02X", 
                        hwaddr[0] & 0xFF,
                        hwaddr[1] & 0xFF,
                        hwaddr[2] & 0xFF,
                        hwaddr[3] & 0xFF,
                        hwaddr[4] & 0xFF,
                        hwaddr[5] & 0xFF
                );

        return safe_strdup(mac);
#elif defined(__NetBSD__)
        struct ifaddrs *ifa, *ifap;
        const char *hwaddr;
        char mac[13], *str = NULL;
        struct sockaddr_dl *sdl;

        if (getifaddrs(&ifap) == -1) {
                debug(LOG_ERR, "getifaddrs(): %s", strerror(errno));
                return NULL;
        }
        for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
                if (strcmp(ifa->ifa_name, ifname) == 0 &&
                                ifa->ifa_addr->sa_family == AF_LINK)
                        break;
        }
        if (ifa == NULL) {
                debug(LOG_ERR, "%s: no link-layer address assigned");
                goto out;
        }
        sdl = (struct sockaddr_dl *)ifa->ifa_addr;
        hwaddr = LLADDR(sdl);
        snprintf(mac, sizeof(mac), "%02X%02X%02X%02X%02X%02X",
                        hwaddr[0] & 0xFF, hwaddr[1] & 0xFF,
                        hwaddr[2] & 0xFF, hwaddr[3] & 0xFF,
                        hwaddr[4] & 0xFF, hwaddr[5] & 0xFF);

        str = safe_strdup(mac);
out:
        freeifaddrs(ifap);
        return str;
#else
        return NULL;
#endif
}

        char *
get_ext_iface(void)
{
#ifdef __linux__
        FILE *input;
        char *device, *gw;
        int i = 1;
        int keep_detecting = 1;
        pthread_cond_t          cond = PTHREAD_COND_INITIALIZER;
        pthread_mutex_t         cond_mutex = PTHREAD_MUTEX_INITIALIZER;
        struct  timespec        timeout;
        device = (char *)malloc(16);
        gw = (char *)malloc(16);
        debug(LOG_DEBUG, "get_ext_iface(): Autodectecting the external interface from routing table");
        while(keep_detecting) {
                input = fopen("/proc/net/route", "r");
                while (!feof(input)) {
                        /* XXX scanf(3) is unsafe, risks overrun */ 
                        fscanf(input, "%s %s %*s %*s %*s %*s %*s %*s %*s %*s %*s\n", device, gw);
                        if (strcmp(gw, "00000000") == 0) {
                                free(gw);
                                debug(LOG_INFO, "get_ext_iface(): Detected %s as the default interface after try %d", device, i);
                                return device;
                        }
                }
                fclose(input);
                debug(LOG_ERR, "get_ext_iface(): Failed to detect the external interface after try %d (maybe the interface is not up yet?).  Retry limit: %d", i, NUM_EXT_INTERFACE_DETECT_RETRY);
                /* Sleep for EXT_INTERFACE_DETECT_RETRY_INTERVAL seconds */
                timeout.tv_sec = time(NULL) + EXT_INTERFACE_DETECT_RETRY_INTERVAL;
                timeout.tv_nsec = 0;
                /* Mutex must be locked for pthread_cond_timedwait... */
                pthread_mutex_lock(&cond_mutex);        
                /* Thread safe "sleep" */
                pthread_cond_timedwait(&cond, &cond_mutex, &timeout);
                /* No longer needs to be locked */
                pthread_mutex_unlock(&cond_mutex);
                //for (i=1; i<=NUM_EXT_INTERFACE_DETECT_RETRY; i++) {
                if (NUM_EXT_INTERFACE_DETECT_RETRY != 0 && i>NUM_EXT_INTERFACE_DETECT_RETRY) {
                        keep_detecting = 0;
                }
                i++;
        }
        debug(LOG_ERR, "get_ext_iface(): Failed to detect the external interface after %d tries, aborting", i);
        exit(1);
        free(device);
        free(gw);
#endif
        return NULL;
        }

        void mark_online() {
                int before;
                int after;

                before = is_online();
                time(&last_online_time);
                after = is_online();

                if (before != after) {
                        debug(LOG_INFO, "ONLINE status became %s", (after ? "ON" : "OFF"));
                }

        }

        void mark_offline() {
                int before;
                int after;

                before = is_online();
                time(&last_offline_time);
                after = is_online();

                if (before != after) {
                        debug(LOG_INFO, "ONLINE status became %s", (after ? "ON" : "OFF"));
                }

                /* If we're offline it definately means the auth server is offline */
                mark_auth_offline();

        }

        int is_online() {
                if (last_online_time == 0 || (last_offline_time - last_online_time) >= (config_get_config()->checkinterval * 2) ) {
                        /* We're probably offline */
                        return (0);
                }
                else {
                        /* We're probably online */
                        return (1);
                }
        }

        void mark_auth_online() {
                int before;
                int after;

                before = is_auth_online();
                time(&last_auth_online_time);
                after = is_auth_online();

                if (before != after) {
                        debug(LOG_INFO, "AUTH_ONLINE status became %s", (after ? "ON" : "OFF"));
                }

                /* If auth server is online it means we're definately online */
                mark_online();

        }

        void mark_auth_offline() {
                int before;
                int after;

                before = is_auth_online();
                time(&last_auth_offline_time);
                after = is_auth_online();

                if (before != after) {
                        debug(LOG_INFO, "AUTH_ONLINE status became %s", (after ? "ON" : "OFF"));
                }

        }

        int is_auth_online() {
                if (!is_online()) {
                        /* If we're not online auth is definately not online :) */
                        return (0);
                }
                else if (last_auth_online_time == 0 || (last_auth_offline_time - last_auth_online_time) >= (config_get_config()->checkinterval * 2) ) {
                        /* Auth is  probably offline */
                        return (0);
                }
                else {
                        /* Auth is probably online */
                        return (1);
                }
        }

        /*
         * @return A string containing human-readable status text. MUST BE free()d by caller
         */
        char * get_status_text() {
                char buffer[STATUS_BUF_SIZ];
                ssize_t len;
                s_config *config;
                t_auth_serv *auth_server;
                t_client        *first;
                int             count;
                unsigned long int uptime = 0;
                unsigned int days = 0, hours = 0, minutes = 0, seconds = 0;
                t_trusted_mac *p;

                len = 0;
                snprintf(buffer, (sizeof(buffer) - len), "WiFiDog status\n\n");
                len = strlen(buffer);

                uptime = time(NULL) - started_time;
                days    = uptime / (24 * 60 * 60);
                uptime -= days * (24 * 60 * 60);
                hours   = uptime / (60 * 60);
                uptime -= hours * (60 * 60);
                minutes = uptime / 60;
                uptime -= minutes * 60;
                seconds = uptime;

                snprintf((buffer + len), (sizeof(buffer) - len), "Version: " VERSION "\n");
                len = strlen(buffer);

                snprintf((buffer + len), (sizeof(buffer) - len), "Uptime: %ud %uh %um %us\n", days, hours, minutes, seconds);
                len = strlen(buffer);

                snprintf((buffer + len), (sizeof(buffer) - len), "Has been restarted: ");
                len = strlen(buffer);
                if (restart_orig_pid) {
                        snprintf((buffer + len), (sizeof(buffer) - len), "yes (from PID %d)\n", restart_orig_pid);
                        len = strlen(buffer);
                }
                else {
                        snprintf((buffer + len), (sizeof(buffer) - len), "no\n");
                        len = strlen(buffer);
                }

                snprintf((buffer + len), (sizeof(buffer) - len), "Internet Connectivity: %s\n", (is_online() ? "yes" : "no"));
                len = strlen(buffer);

                snprintf((buffer + len), (sizeof(buffer) - len), "Auth server reachable: %s\n", (is_auth_online() ? "yes" : "no"));
                len = strlen(buffer);

                snprintf((buffer + len), (sizeof(buffer) - len), "Clients served this session: %lu\n\n", served_this_session);
                len = strlen(buffer);

                LOCK_CLIENT_LIST();

                first = client_get_first_client();

                if (first == NULL) {
                        count = 0;
                } else {
                        count = 1;
                        while (first->next != NULL) {
                                first = first->next;
                                count++;
                        }
                }

                snprintf((buffer + len), (sizeof(buffer) - len), "%d clients "
                                "connected.\n", count);
                len = strlen(buffer);

                first = client_get_first_client();

                count = 0;
                while (first != NULL) {
                        snprintf((buffer + len), (sizeof(buffer) - len), "\nClient %d\n", count);
                        len = strlen(buffer);

                        snprintf((buffer + len), (sizeof(buffer) - len), "  IP: %s MAC: %s\n", first->ip, first->mac);
                        len = strlen(buffer);

                        snprintf((buffer + len), (sizeof(buffer) - len), "  Token: %s\n", first->token);
                        len = strlen(buffer);

                        snprintf((buffer + len), (sizeof(buffer) - len), "  Downloaded: %llu\n  Uploaded: %llu\n" , first->counters.incoming, first->counters.outgoing);
                        len = strlen(buffer);

                        count++;
                        first = first->next;
                }

                UNLOCK_CLIENT_LIST();

                config = config_get_config();

                if (config->trustedmaclist != NULL) {
                        snprintf((buffer + len), (sizeof(buffer) - len), "\nTrusted MAC addresses:\n");
                        len = strlen(buffer);

                        for (p = config->trustedmaclist; p != NULL; p = p->next) {
                                snprintf((buffer + len), (sizeof(buffer) - len), "  %s\n", p->mac);
                                len = strlen(buffer);
                        }
                }

                snprintf((buffer + len), (sizeof(buffer) - len), "\nAuthentication servers:\n");
                len = strlen(buffer);

                LOCK_CONFIG();

                for (auth_server = config->auth_servers; auth_server != NULL; auth_server = auth_server->next) {
                        snprintf((buffer + len), (sizeof(buffer) - len), "  Host: %s (%s)\n", auth_server->authserv_hostname, auth_server->last_ip);
                        len = strlen(buffer);
                }

                UNLOCK_CONFIG();

                return safe_strdup(buffer);
        }