/*
  *  Copyright (C) 2014 Cisco and/or its affiliates. All rights reserved.
  *
  *  Author: Shawn Webb
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  *
  *  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, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  *  MA 02110-1301, USA.
  */
 

 #if HAVE_CONFIG_H
 #include "clamav-config.h"
 #endif
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 
 #if HAVE_UNISTD_H

 #include <unistd.h>

 #endif

 
 #include <sys/types.h>

 #include <fcntl.h>
 
 #if !defined(_WIN32)

 #include <sys/socket.h>
 #include <netdb.h>
 #include <sys/ioctl.h>

 #endif

 #if defined(HAVE_GETIFADDRS)

 #include <net/if.h>

 #if defined(HAVE_NET_IF_DL_H)

 #include <net/if_dl.h>

 #endif

 #include <ifaddrs.h>

 #endif
 

 #if defined(SIOCGIFHWADDR) && !defined(__GNU__)

 #if defined(_AIX)

 #include <sys/ndd_var.h>
 #include <sys/kinfo.h>
 #else

 #include <linux/sockios.h>
 #endif

 #endif

 
 #include <errno.h>
 

 #include "clamav.h"

 #include "hostid.h"

 #include "libclamav/others.h"

 struct device *get_device_entry(struct device *devices, size_t *ndevices, const char *name);
 

 struct device *get_device_entry(struct device *devices, size_t *ndevices, const char *name)
 {
     void *p;
     size_t i;
 
     if ((devices)) {
         int found = 0;
 

         for (i = 0; i < *ndevices; i++) {
             if (!strcmp(devices[i].name, name)) {

                 found = 1;
                 break;
             }
         }
 
         if (!found) {
             p = realloc(devices, sizeof(struct device) * (*ndevices + 1));
             if (!(p)) {
                 for (i=0; i < *ndevices; i++)
                     free(devices[i].name);
                 free(devices);
                 return NULL;
             }
             devices = p;

 
             memset(devices + *ndevices, 0x00, sizeof(struct device));

             *ndevices = *ndevices + 1;

         }
     } else {

         devices = calloc(1, sizeof(struct device));

         if (!(devices))
             return NULL;
 
         *ndevices = 1;
     }
 

     if (*ndevices && !(devices[*ndevices - 1].name) && name)
         devices[*ndevices - 1].name = strdup(name);

     return devices;
 }
 

 #if HAVE_GETIFADDRS

 struct device *get_devices(void)
 {

     struct ifaddrs *addrs=NULL, *addr;

     struct device *devices=NULL;
     size_t ndevices=0, i, j;

     void *p;
     uint8_t *mac;
     int sock;

 #if defined(SIOCGIFHWADDR) && !defined(__GNU__)

     struct ifreq ifr;

 #else
     struct sockaddr_dl *sdl;
 #endif

 
     if (getifaddrs(&addrs))
         return NULL;
 
     for (addr = addrs; addr != NULL; addr = addr->ifa_next) {
         if (!(addr->ifa_addr))
             continue;
 

         /*
          * Even though POSIX (BSD) sockets define AF_LINK, Linux decided to be clever
          * and use AF_PACKET instead.
          */

 #if defined(AF_PACKET)

         if (addr->ifa_addr->sa_family != AF_PACKET)
             continue;

 #elif defined(AF_LINK)
         if (addr->ifa_addr->sa_family != AF_LINK)
             continue;
 #else
         break; /* We don't support anything else */
 #endif

 
         devices = get_device_entry(devices, &ndevices, addr->ifa_name);
         if (!(devices)) {
             freeifaddrs(addrs);
             return NULL;
         }

         /*
          * Grab the MAC address for all devices that have them.
          * Linux doesn't support (struct sockaddr_dl) as POSIX (BSD) sockets require.
          * Instead, Linux uses its own ioctl. This code only runs if we're not Linux,
          * Windows, or FreeBSD.
          */

 #if !defined(SIOCGIFHWADDR) || defined(__GNU__)

         for (i=0; i < ndevices; i++) {

             if (!(strcmp(devices[i].name, addr->ifa_name))) {

                 sdl = (struct sockaddr_dl *)(addr->ifa_addr);
 
 #if defined(LLADDR)
                 mac = LLADDR(sdl);
 #else
                 mac = ((uint8_t *)(sdl->sdl_data + sdl->sdl_nlen));
 #endif

                 for (j=0; j<6; j++)
                     snprintf(devices[i].mac+strlen(devices[i].mac), sizeof(devices[i].mac)-strlen(devices[i].mac)-1, "%02x:", mac[j]);

 
                 break;
             }
         }
 #endif

     }
 
     if (addrs) {
         freeifaddrs(addrs);
         addrs = NULL;
     }
 

     /* This is the Linux version of getting the MAC addresses */

 #if defined(SIOCGIFHWADDR) && !defined(__GNU__)

     for (i=0; i < ndevices; i++) {

         if (!(devices[i].name))
             continue;
 

         memset(&ifr, 0x00, sizeof(struct ifreq));

         memset(devices[i].mac, 0x00, sizeof(devices[i].mac));

         strcpy(ifr.ifr_name, devices[i].name);

         sock = socket(AF_INET, SOCK_DGRAM, 0);
         if (sock < 0)
             goto err;

         if (ioctl(sock, SIOCGIFHWADDR, &ifr)) {
             close(sock);
             goto err;
         }

         close(sock);

         mac = ((uint8_t *)(ifr.ifr_ifru.ifru_hwaddr.sa_data));

         if (!(mac))
             continue;

         for (j=0; j<6; j++)
             snprintf(devices[i].mac+strlen(devices[i].mac), sizeof(devices[i].mac)-strlen(devices[i].mac)-1, "%02x:", mac[j]);

     }

 #endif

 
     p = realloc(devices, sizeof(struct device) * (ndevices + 1));
     if (!(p))
         goto err;
 
     devices = p;
     devices[ndevices].name =  NULL;
     memset(devices[ndevices].mac, 0x00, sizeof(devices[ndevices].mac));
 
     return devices;
 
 err:
     if (devices) {

         for (i=0; i < ndevices; i++)
             if (devices[i].name)
                 free(devices[i].name);

 
         free(devices);
     }
 
     return NULL;
 }
 #else
 struct device *get_devices(void)
 {
     return NULL;
 }
 #endif /* HAVE_GETIFADDRS */
 
 #if !HAVE_SYSCTLBYNAME && !defined(_WIN32)

 /*
  * Since we're getting potentially sensitive data (MAC addresses for all devices on the system),
  * hash all the MAC addresses to provide basic anonymity and security.
  */

 char *internal_get_host_id(void)
 {
     size_t i;
     unsigned char raw_md5[16];
     char *printable_md5;
     struct device *devices;

     void *ctx;

 
     devices = get_devices();
     if (!(devices))
         return NULL;
 

     printable_md5 = calloc(1, 37);

     if (!(printable_md5)) {
         free(devices);

         return NULL;

     }

     ctx = cl_hash_init("md5");

     if (!(ctx)) {
         for (i=0; devices[i].name != NULL; i++)
             free(devices[i].name);
 
         free(devices);
         free(printable_md5);
 
         return NULL;
     }
 

     for (i=0; devices[i].name != NULL; i++)

         cl_update_hash(ctx, devices[i].mac, sizeof(devices[i].mac));

     cl_finish_hash(ctx, raw_md5);

 
     for (i=0; devices[i].name != NULL; i++)
         free(devices[i].name);
     free(devices);
 

     for (i=0; i < sizeof(raw_md5); i++) {
         size_t len = strlen(printable_md5);
         switch (len) {
             case 8:
             case 13:
             case 18:
             case 23:
                 printable_md5[len++] = '-';
                 break;
         }
 
         sprintf(printable_md5+len, "%02x", raw_md5[i]);
     }

 
     return printable_md5;
 }
 #endif