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-rw-r--r--src/Erebos/Network/ifaddrs.c279
1 files changed, 279 insertions, 0 deletions
diff --git a/src/Erebos/Network/ifaddrs.c b/src/Erebos/Network/ifaddrs.c
new file mode 100644
index 0000000..ff4382a
--- /dev/null
+++ b/src/Erebos/Network/ifaddrs.c
@@ -0,0 +1,279 @@
+#include "ifaddrs.h"
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef _WIN32
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <ifaddrs.h>
+#include <endian.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#else
+#include <winsock2.h>
+#include <ws2ipdef.h>
+#include <ws2tcpip.h>
+#endif
+
+#define DISCOVERY_MULTICAST_GROUP "ff12:b6a4:6b1f:969:caee:acc2:5c93:73e1"
+
+uint32_t * join_multicast(int fd, size_t * count)
+{
+ size_t capacity = 16;
+ *count = 0;
+ uint32_t * interfaces = malloc(sizeof(uint32_t) * capacity);
+
+#ifdef _WIN32
+ interfaces[0] = 0;
+ *count = 1;
+#else
+ struct ifaddrs * addrs;
+ if (getifaddrs(&addrs) < 0)
+ return 0;
+
+ for (struct ifaddrs * ifa = addrs; ifa; ifa = ifa->ifa_next) {
+ if( ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET6 &&
+ ! (ifa->ifa_flags & IFF_LOOPBACK) &&
+ (ifa->ifa_flags & IFF_MULTICAST) &&
+ ! IN6_IS_ADDR_LINKLOCAL( & ((struct sockaddr_in6 *) ifa->ifa_addr)->sin6_addr ) ){
+ int idx = if_nametoindex(ifa->ifa_name);
+
+ bool seen = false;
+ for (size_t i = 0; i < *count; i++) {
+ if (interfaces[i] == idx) {
+ seen = true;
+ break;
+ }
+ }
+ if (seen)
+ continue;
+
+ if (*count + 1 >= capacity) {
+ capacity *= 2;
+ uint32_t * nret = realloc(interfaces, sizeof(uint32_t) * capacity);
+ if (nret) {
+ interfaces = nret;
+ } else {
+ free(interfaces);
+ *count = 0;
+ return NULL;
+ }
+ }
+
+ interfaces[*count] = idx;
+ (*count)++;
+ }
+ }
+
+ freeifaddrs(addrs);
+#endif
+
+ for (size_t i = 0; i < *count; i++) {
+ struct ipv6_mreq group;
+ group.ipv6mr_interface = interfaces[i];
+ inet_pton(AF_INET6, DISCOVERY_MULTICAST_GROUP, &group.ipv6mr_multiaddr);
+ int ret = setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP,
+ (const void *) &group, sizeof(group));
+ if (ret < 0)
+ fprintf(stderr, "IPV6_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
+ }
+
+ return interfaces;
+}
+
+static bool copy_local_address( struct InetAddress * dst, const struct sockaddr * src )
+{
+ int family = src->sa_family;
+
+ if( family == AF_INET ){
+ struct in_addr * addr = & (( struct sockaddr_in * ) src)->sin_addr;
+ if (! ((ntohl( addr->s_addr ) & 0xff000000) == 0x7f000000) && // loopback
+ ! ((ntohl( addr->s_addr ) & 0xffff0000) == 0xa9fe0000) // link-local
+ ){
+ dst->family = family;
+ memcpy( & dst->addr, addr, sizeof( * addr ));
+ return true;
+ }
+ }
+
+ if( family == AF_INET6 ){
+ struct in6_addr * addr = & (( struct sockaddr_in6 * ) src)->sin6_addr;
+ if (! IN6_IS_ADDR_LOOPBACK( addr ) &&
+ ! IN6_IS_ADDR_LINKLOCAL( addr )
+ ){
+ dst->family = family;
+ memcpy( & dst->addr, addr, sizeof( * addr ));
+ return true;
+ }
+ }
+
+ return false;
+}
+
+#ifndef _WIN32
+
+struct InetAddress * local_addresses( size_t * count )
+{
+ struct ifaddrs * addrs;
+ if( getifaddrs( &addrs ) < 0 )
+ return 0;
+
+ * count = 0;
+ size_t capacity = 16;
+ struct InetAddress * ret = malloc( sizeof(* ret) * capacity );
+
+ for( struct ifaddrs * ifa = addrs; ifa; ifa = ifa->ifa_next ){
+ if ( ifa->ifa_addr ){
+ int family = ifa->ifa_addr->sa_family;
+ if( family == AF_INET || family == AF_INET6 ){
+ if( (* count) >= capacity ){
+ capacity *= 2;
+ struct InetAddress * nret = realloc( ret, sizeof(* ret) * capacity );
+ if (nret) {
+ ret = nret;
+ } else {
+ free( ret );
+ freeifaddrs( addrs );
+ return 0;
+ }
+ }
+
+ if( copy_local_address( & ret[ * count ], ifa->ifa_addr ))
+ (* count)++;
+ }
+ }
+ }
+
+ freeifaddrs(addrs);
+ return ret;
+}
+
+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);
+ freeifaddrs(addrs);
+ 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>
+#include <iptypes.h>
+#include <iphlpapi.h>
+
+#pragma comment(lib, "ws2_32.lib")
+
+struct InetAddress * local_addresses( size_t * count )
+{
+ * count = 0;
+ struct InetAddress * ret = NULL;
+
+ ULONG bufsize = 15000;
+ IP_ADAPTER_ADDRESSES * buf = NULL;
+
+ DWORD rv = 0;
+
+ do {
+ buf = realloc( buf, bufsize );
+ rv = GetAdaptersAddresses( AF_UNSPEC, 0, NULL, buf, & bufsize );
+
+ if( rv == ERROR_BUFFER_OVERFLOW )
+ continue;
+ } while (0);
+
+ if( rv == NO_ERROR ){
+ size_t capacity = 16;
+ ret = malloc( sizeof( * ret ) * capacity );
+
+ for( IP_ADAPTER_ADDRESSES * cur = (IP_ADAPTER_ADDRESSES *) buf;
+ cur && (* count) < capacity;
+ cur = cur->Next ){
+
+ for( IP_ADAPTER_UNICAST_ADDRESS * curAddr = cur->FirstUnicastAddress;
+ curAddr && (* count) < capacity;
+ curAddr = curAddr->Next ){
+
+ if( copy_local_address( & ret[ * count ], curAddr->Address.lpSockaddr ))
+ (* count)++;
+ }
+ }
+ }
+
+cleanup:
+ free( buf );
+ return ret;
+}
+
+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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