net.c

IEEE1588 Protocol,用于同步局域网各站点时间

/* net.c */

#include "../ptpd.h"

Boolean lookupSubdomainAddress(Octet *subdomainName, Octet *subdomainAddress)
{
  UInteger32 h;
  
  /* set multicast group address based on subdomainName */
  if (!memcmp(subdomainName, DEFAULT_PTP_DOMAIN_NAME, PTP_SUBDOMAIN_NAME_LENGTH))
    memcpy(subdomainAddress, DEFAULT_PTP_DOMAIN_ADDRESS, NET_ADDRESS_LENGTH);
  else if(!memcmp(subdomainName, ALTERNATE_PTP_DOMAIN1_NAME, PTP_SUBDOMAIN_NAME_LENGTH))
    memcpy(subdomainAddress, ALTERNATE_PTP_DOMAIN1_ADDRESS, NET_ADDRESS_LENGTH);
  else if(!memcmp(subdomainName, ALTERNATE_PTP_DOMAIN2_NAME, PTP_SUBDOMAIN_NAME_LENGTH))
    memcpy(subdomainAddress, ALTERNATE_PTP_DOMAIN2_ADDRESS, NET_ADDRESS_LENGTH);
  else if(!memcmp(subdomainName, ALTERNATE_PTP_DOMAIN3_NAME, PTP_SUBDOMAIN_NAME_LENGTH))
    memcpy(subdomainAddress, ALTERNATE_PTP_DOMAIN3_ADDRESS, NET_ADDRESS_LENGTH);
  else
  {
    h = crc_algorithm(subdomainName, PTP_SUBDOMAIN_NAME_LENGTH) % 3;
    switch(h)
    {
    case 0:
      memcpy(subdomainAddress, ALTERNATE_PTP_DOMAIN1_ADDRESS, NET_ADDRESS_LENGTH);
      break;
    case 1:
      memcpy(subdomainAddress, ALTERNATE_PTP_DOMAIN2_ADDRESS, NET_ADDRESS_LENGTH);
      break;
    case 2:
      memcpy(subdomainAddress, ALTERNATE_PTP_DOMAIN3_ADDRESS, NET_ADDRESS_LENGTH);
      break;
    default:
      ERROR("handle out of range for '%s'!\n", subdomainName);
      return FALSE;
    }
  }
  
  return TRUE;
}

UInteger8 lookupCommunicationTechnology(UInteger8 communicationTechnology)
{
#if defined(linux)
  
  switch(communicationTechnology)
  {
  case ARPHRD_ETHER:
  case ARPHRD_EETHER:
  case ARPHRD_IEEE802:
    return PTP_ETHER;
    
  default:
    break;
  }
  
#elif defined(BSD_INTERFACE_FUNCTIONS)
  
#endif
  
  return PTP_DEFAULT;
}

UInteger32 findIface(Octet *ifaceName, UInteger8 *communicationTechnology,
  Octet *uuid, NetPath *netPath)
{
#if defined(linux)

  /* depends on linux specific ioctls (see 'netdevice' man page) */
  int i, flags;
  struct ifconf data;
  struct ifreq device[IFCONF_LENGTH];
  
  data.ifc_len = sizeof(device);
  data.ifc_req = device;
  
  memset(data.ifc_buf,0,data.ifc_len);
  
  flags = IFF_UP|IFF_RUNNING|IFF_MULTICAST;
  
  /* look for an interface if none specified */
  if(ifaceName[0] != '\0')
  {
    i = 0;
    memcpy(device[i].ifr_name, ifaceName, IFACE_NAME_LENGTH);
    
    if(ioctl(netPath->eventSock, SIOCGIFHWADDR, &device[i]) < 0)
      DBGV("failed to get hardware address\n");
    else if((*communicationTechnology = lookupCommunicationTechnology(device[i].ifr_hwaddr.sa_family)) == PTP_DEFAULT)
      DBGV("unsupported communication technology (%d)\n", *communicationTechnology);
    else
      memcpy(uuid, device[i].ifr_hwaddr.sa_data, PTP_UUID_LENGTH);
  }
  else
  {
    /* no iface specified */
    /* get list of network interfaces*/
    if(ioctl(netPath->eventSock, SIOCGIFCONF, &data) < 0)
    {
      PERROR("failed query network interfaces");
      return 0;
    }
    
    if(data.ifc_len >= sizeof(device))
      DBG("device list may exceed allocated space\n");
    
    /* search through interfaces */
    for(i=0; i < data.ifc_len/sizeof(device[0]); ++i)
    {
      DBGV("%d %s %s\n",i,device[i].ifr_name,inet_ntoa(((struct sockaddr_in *)&device[i].ifr_addr)->sin_addr));
      
      if(ioctl(netPath->eventSock, SIOCGIFFLAGS, &device[i]) < 0)
        DBGV("failed to get device flags\n");
      else if((device[i].ifr_flags&flags) != flags)
        DBGV("does not meet requirements (%08x, %08x)\n", device[i].ifr_flags, flags);
      else if(ioctl(netPath->eventSock, SIOCGIFHWADDR, &device[i]) < 0)
        DBGV("failed to get hardware address\n");
      else if((*communicationTechnology = lookupCommunicationTechnology(device[i].ifr_hwaddr.sa_family)) == PTP_DEFAULT)
        DBGV("unsupported communication technology (%d)\n", *communicationTechnology);
      else
      {
        DBGV("found interface (%s)\n", device[i].ifr_name);
        
        memcpy(uuid, device[i].ifr_hwaddr.sa_data, PTP_UUID_LENGTH);
        memcpy(ifaceName, device[i].ifr_name, IFACE_NAME_LENGTH);
        
        break;
      }
    }
  }
  
  if(ifaceName[0] == '\0')
  {
    ERROR("failed to find a usable interface\n");
    return 0;
  }
  
  if(ioctl(netPath->eventSock, SIOCGIFADDR, &device[i]) < 0)
  {
    PERROR("failed to get ip address");
    return 0;
  }
  
  return ((struct sockaddr_in *)&device[i].ifr_addr)->sin_addr.s_addr;

#elif defined(BSD_INTERFACE_FUNCTIONS)

  struct ifaddrs *if_list, *ifv4, *ifh;

  if (getifaddrs(&if_list) < 0)
  {
    PERROR("getifaddrs() failed");
    return FALSE;
  }

  /* find an IPv4, multicast, UP interface, right name(if supplied) */
  for (ifv4 = if_list; ifv4 != NULL; ifv4 = ifv4->ifa_next)
  {
    if ((ifv4->ifa_flags & IFF_UP) == 0)
      continue;
    if ((ifv4->ifa_flags & IFF_RUNNING) == 0)
      continue;
    if ((ifv4->ifa_flags & IFF_LOOPBACK))
      continue;
    if ((ifv4->ifa_flags & IFF_MULTICAST) == 0)
      continue;
    if (ifv4->ifa_addr->sa_family != AF_INET)  /* must have IPv4 address */
      continue;

    if (ifaceName[0] && strncmp(ifv4->ifa_name, ifaceName, IF_NAMESIZE) != 0)
      continue;

    break;
  }

  if (ifv4 == NULL)
  {
    if (ifaceName[0])
    {
      ERROR("interface \"%s\" does not exist, or is not appropriate\n", ifaceName);
      return FALSE;
    }
    ERROR("no suitable interfaces found!");
    return FALSE;
  }

  /* find the AF_LINK info associated with the chosen interface */
  for (ifh = if_list; ifh != NULL; ifh = ifh->ifa_next)
  {
    if (ifh->ifa_addr->sa_family != AF_LINK)
      continue;
    if (strncmp(ifv4->ifa_name, ifh->ifa_name, IF_NAMESIZE) == 0)
      break;
  }

  if (ifh == NULL)
  {
    ERROR("could not get hardware address for interface \"%s\"\n", ifv4->ifa_name);
    return FALSE;
  }

  /* check that the interface TYPE is OK */
  if ( ((struct sockaddr_dl *)ifh->ifa_addr)->sdl_type != IFT_ETHER )
  {
    ERROR("\"%s\" is not an ethernet interface!\n", ifh->ifa_name);
    return FALSE;
  }

  printf("==> %s %s %s\n", ifv4->ifa_name,
       inet_ntoa(((struct sockaddr_in *)ifv4->ifa_addr)->sin_addr),
        ether_ntoa((struct ether_addr *)LLADDR((struct sockaddr_dl *)ifh->ifa_addr))
        );

  *communicationTechnology = PTP_ETHER;
  memcpy(ifaceName, ifh->ifa_name, IFACE_NAME_LENGTH);
  memcpy(uuid, LLADDR((struct sockaddr_dl *)ifh->ifa_addr), PTP_UUID_LENGTH);

  return ((struct sockaddr_in *)ifv4->ifa_addr)->sin_addr.s_addr;

#endif
}

/* start all of the UDP stuff */
/* must specify 'subdomainName', optionally 'ifaceName', if not then pass ifaceName == "" */
/* returns other args */
/* on socket options, see the 'socket(7)' and 'ip' man pages */
Boolean netInit(NetPath *netPath, RunTimeOpts *rtOpts, PtpClock *ptpClock)
{
  int temp, i;
  struct in_addr interfaceAddr, netAddr;
  struct sockaddr_in addr;
  struct ip_mreq imr;
  char addrStr[NET_ADDRESS_LENGTH];
  char *s;
  
  DBG("netInit\n");
  
  /* open sockets */
  if( (netPath->eventSock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP) ) < 0
    || (netPath->generalSock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP) ) < 0 )
  {
    PERROR("failed to initalize sockets");
    return FALSE;
  }

  /* find a network interface */
  if( !(interfaceAddr.s_addr = findIface(rtOpts->ifaceName, &ptpClock->port_communication_technology,
    ptpClock->port_uuid_field, netPath)) )
    return FALSE;
  
  temp = 1;  /* allow address reuse */
  if( setsockopt(netPath->eventSock, SOL_SOCKET, SO_REUSEADDR, &temp, sizeof(int)) < 0
    || setsockopt(netPath->generalSock, SOL_SOCKET, SO_REUSEADDR, &temp, sizeof(int)) < 0 )
  {
    DBG("failed to set socket reuse\n");
  }

  /* bind sockets */
  /* need INADDR_ANY to allow receipt of multi-cast and uni-cast messages */
  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = htonl(INADDR_ANY);
  addr.sin_port = htons(PTP_EVENT_PORT);
  if(bind(netPath->eventSock, (struct sockaddr*)&addr, sizeof(struct sockaddr_in)) < 0)
  {
    PERROR("failed to bind event socket");
    return FALSE;
  }
  
  addr.sin_port = htons(PTP_GENERAL_PORT);
  if(bind(netPath->generalSock, (struct sockaddr*)&addr, sizeof(struct sockaddr_in)) < 0)
  {
    PERROR("failed to bind general socket");
    return FALSE;
  }
  
  /* set general and port address */
  *(Integer16*)ptpClock->event_port_address = PTP_EVENT_PORT;
  *(Integer16*)ptpClock->general_port_address = PTP_GENERAL_PORT;
  
  /* send a uni-cast address if specified (useful for testing) */
  if(rtOpts->unicastAddress[0])
  {
    if(!inet_aton(rtOpts->unicastAddress, &netAddr))
    {
      ERROR("failed to encode uni-cast address: %s\n", rtOpts->unicastAddress);
      return FALSE;
    }
    
    netPath->unicastAddr = netAddr.s_addr;
  }
  else
    netPath->unicastAddr = 0;
  
  /* resolve PTP subdomain */