static void
s_get_interface (zre_udp_t *self)
{
#if defined (__UNIX__)
# if defined (HAVE_GETIFADDRS) && defined (HAVE_FREEIFADDRS)
struct ifaddrs *interfaces;
if (getifaddrs (&interfaces) == 0) {
struct ifaddrs *interface = interfaces;
while (interface) {
// Hopefully the last interface will be WiFi or Ethernet
if (interface->ifa_addr->sa_family == AF_INET) {
self->address = *(struct sockaddr_in *) interface->ifa_addr;
self->broadcast = *(struct sockaddr_in *) interface->ifa_broadaddr;
self->broadcast.sin_port = htons (self->port_nbr);
if (s_wireless_nic (interface->ifa_name))
break;
}
interface = interface->ifa_next;
}
}
freeifaddrs (interfaces);
# else
struct ifreq ifr;
memset (&ifr, 0, sizeof (ifr));
# if !defined (LIBZRE_HAVE_ANDROID)
// TODO: Using hardcoded wlan0 is ugly
if (!s_wireless_nic ("wlan0"))
s_handle_io_error ("wlan0_not_exist");
# endif
int sock = 0;
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
s_handle_io_error ("foo_socket_not_opened");
// Get interface address
ifr.ifr_addr.sa_family = AF_INET;
strncpy (ifr.ifr_name, "wlan0", sizeof (ifr.ifr_name));
int rc = ioctl (sock, SIOCGIFADDR, (caddr_t) &ifr, sizeof (struct ifreq));
if (rc == -1)
s_handle_io_error ("siocgifaddr");
// Get interface broadcast address
memcpy (&self->address, ((struct sockaddr_in *) &ifr.ifr_addr),
sizeof (struct sockaddr_in));
rc = ioctl (sock, SIOCGIFBRDADDR, (caddr_t) &ifr, sizeof (struct ifreq));
if (rc == -1)
s_handle_io_error ("siocgifbrdaddr");
memcpy (&self->broadcast, ((struct sockaddr_in *) &ifr.ifr_broadaddr),
sizeof (struct sockaddr_in));
self->broadcast.sin_port = htons (self->port_nbr);
close (sock);
# endif
# elif defined (__WINDOWS__)
// Currently does not filter for wireless NIC
ULONG addr_size = 0;
DWORD rc = GetAdaptersAddresses (AF_INET,
GAA_FLAG_INCLUDE_PREFIX, NULL, NULL, &addr_size);
assert (rc == ERROR_BUFFER_OVERFLOW);
PIP_ADAPTER_ADDRESSES pip_addresses = malloc (addr_size);
rc = GetAdaptersAddresses (AF_INET,
GAA_FLAG_INCLUDE_PREFIX, NULL, pip_addresses, &addr_size);
assert (rc == NO_ERROR);
PIP_ADAPTER_ADDRESSES cur_address = pip_addresses;
while (cur_address) {
PIP_ADAPTER_UNICAST_ADDRESS pUnicast = cur_address->FirstUnicastAddress;
PIP_ADAPTER_PREFIX pPrefix = cur_address->FirstPrefix;
if (pUnicast && pPrefix) {
// self->broadcast.sin_addr is replaced with 255.255.255.255 in zre_udp_send()
self->address = *(struct sockaddr_in *)(pUnicast->Address.lpSockaddr);
self->broadcast = *(struct sockaddr_in *)(pPrefix->Address.lpSockaddr);
self->broadcast.sin_addr.s_addr |= htonl ((1 << (32 - pPrefix->PrefixLength)) - 1);
}
self->broadcast.sin_port = htons (self->port_nbr);
cur_address = cur_address->Next;
}
free (pip_addresses);
# else
# error "Interface detection TBD on this operating system"
# endif
}
zre_udp_t *
zre_udp_new (int port_nbr)
{
zre_udp_t *self = (zre_udp_t *) zmalloc (sizeof (zre_udp_t));
self->port_nbr = port_nbr;
// Create UDP socket
self->handle = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (self->handle == -1)
s_handle_io_error ("socket");
// Ask operating system to let us do broadcasts from socket
int on = 1;
if (setsockopt (self->handle, SOL_SOCKET,
SO_BROADCAST, (char *)&on, sizeof (on)) == -1)
s_handle_io_error ("setsockopt (SO_BROADCAST)");
// Allow multiple processes to bind to socket; incoming
// messages will come to each process
if (setsockopt (self->handle, SOL_SOCKET,
SO_REUSEADDR, (char *)&on, sizeof (on)) == -1)
s_handle_io_error ("setsockopt (SO_REUSEADDR)");
#if defined (SO_REUSEPORT)
if (setsockopt (self->handle, SOL_SOCKET,
SO_REUSEPORT, &on, sizeof (on)) == -1)
s_handle_io_error ("setsockopt (SO_REUSEPORT)");
#endif
// PROBLEM: this design will not survive the network interface being
// killed and restarted while the program is running.
struct sockaddr_in sockaddr = { 0 };
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons (self->port_nbr);
sockaddr.sin_addr.s_addr = htonl (INADDR_ANY);
if (bind (self->handle, (struct sockaddr *) &sockaddr, sizeof (sockaddr)) == -1)
s_handle_io_error ("bind");
# if defined (__UNIX__)
# if defined (HAVE_GETIFADDRS) && defined (HAVE_FREEIFADDRS)
struct ifaddrs *interfaces;
if (getifaddrs (&interfaces) == 0) {
struct ifaddrs *interface = interfaces;
while (interface) {
// Hopefully the last interface will be WiFi
if (interface->ifa_addr->sa_family == AF_INET) {
self->address = *(struct sockaddr_in *) interface->ifa_addr;
self->broadcast = *(struct sockaddr_in *) interface->ifa_broadaddr;
self->broadcast.sin_port = htons (self->port_nbr);
if (s_wireless_nic (interface->ifa_name))
break;
}
interface = interface->ifa_next;
}
}
freeifaddrs (interfaces);
# else
struct ifreq ifr;
memset (&ifr, 0, sizeof (ifr));
/* TODO: Using hardcoded wlan0 is ugly */
# if !defined ( LIBZRE_HAVE_ANDROID )
if (!s_wireless_nic ("wlan0"))
s_handle_io_error ("wlan0_not_exist");
# endif
int sock = 0;
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
s_handle_io_error ("foo_socket_not_opened");
ifr.ifr_addr.sa_family = AF_INET;
strncpy (ifr.ifr_name, "wlan0", sizeof (ifr.ifr_name));
int rc = ioctl (sock, SIOCGIFADDR, (caddr_t) &ifr, sizeof (struct ifreq));
if (rc == -1)
s_handle_io_error ("siocgifaddr");
memcpy (&self->address, ((struct sockaddr_in*) &ifr.ifr_addr), sizeof (struct sockaddr_in));
rc = ioctl (sock, SIOCGIFBRDADDR, (caddr_t) &ifr, sizeof (struct ifreq));
if (rc == -1)
s_handle_io_error ("siocgifbrdaddr");
memcpy (&self->broadcast, ((struct sockaddr_in*) &ifr.ifr_broadaddr), sizeof (struct sockaddr_in));
self->broadcast.sin_port = htons (self->port_nbr);
close (sock);
# endif
if (self->host)
free (self->host);
self->host = zmalloc (INET_ADDRSTRLEN);
inet_ntop (AF_INET, &self->address.sin_addr, self->host, sizeof (sockaddr));
# elif defined (__WINDOWS__)
s_win_get_interface(self);
if (self->host)
free (self->host);
self->host = zmalloc (INET_ADDRSTRLEN);
getnameinfo ((struct sockaddr *)&self->address, sizeof (self->address), self->host, INET_ADDRSTRLEN, NULL, 0, NI_NUMERICHOST);
# else
# error "Interface detection TBD on this operating system"
# endif
return self;
}
