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#include "ifaddrs.h"
#ifndef _WIN32
#include <arpa/inet.h>
#include <ifaddrs.h>
#include <net/if.h>
#include <stdlib.h>
#include <sys/types.h>
#include <endian.h>
uint32_t * broadcast_addresses(void)
{
struct ifaddrs * addrs;
if (getifaddrs(&addrs) < 0)
return 0;
size_t capacity = 16, count = 0;
uint32_t * ret = malloc(sizeof(uint32_t) * capacity);
for (struct ifaddrs * ifa = addrs; ifa; ifa = ifa->ifa_next) {
if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET &&
ifa->ifa_flags & IFF_BROADCAST) {
if (count + 2 >= capacity) {
capacity *= 2;
uint32_t * nret = realloc(ret, sizeof(uint32_t) * capacity);
if (nret) {
ret = nret;
} else {
free(ret);
return 0;
}
}
ret[count] = ((struct sockaddr_in*)ifa->ifa_broadaddr)->sin_addr.s_addr;
count++;
}
}
freeifaddrs(addrs);
ret[count] = 0;
return ret;
}
#else // _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#pragma comment(lib, "ws2_32.lib")
uint32_t * broadcast_addresses(void)
{
uint32_t * ret = NULL;
SOCKET wsock = INVALID_SOCKET;
struct WSAData wsaData;
if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
return NULL;
wsock = WSASocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP, NULL, 0, 0);
if (wsock == INVALID_SOCKET)
goto cleanup;
INTERFACE_INFO InterfaceList[32];
unsigned long nBytesReturned;
if (WSAIoctl(wsock, SIO_GET_INTERFACE_LIST, 0, 0,
InterfaceList, sizeof(InterfaceList),
&nBytesReturned, 0, 0) == SOCKET_ERROR)
goto cleanup;
int numInterfaces = nBytesReturned / sizeof(INTERFACE_INFO);
size_t capacity = 16, count = 0;
ret = malloc(sizeof(uint32_t) * capacity);
for (int i = 0; i < numInterfaces && count < capacity - 1; i++)
if (InterfaceList[i].iiFlags & IFF_BROADCAST)
ret[count++] = InterfaceList[i].iiBroadcastAddress.AddressIn.sin_addr.s_addr;
ret[count] = 0;
cleanup:
if (wsock != INVALID_SOCKET)
closesocket(wsock);
WSACleanup();
return ret;
}
#endif
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