Let us start here, from square one. No, from Zero!

2022-09-30 22:45:51 +09:00
parent 14215af0d1
commit b7a60638a4
1005 changed files with 303069 additions and 0 deletions
@@ -0,0 +1,114 @@
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#include "netutils.h"
+#include <iphlpapi.h>
+#include <windows.h>
+#include "util/utils.h"
+
+
+namespace netutils {
+
+    std::vector<std::string> get_local_addresses() {
+        std::vector<std::string> return_addresses;
+
+        // use 16KB buffer and resize if needed
+        DWORD buffer_size = 16 * 1024;
+        IP_ADAPTER_ADDRESSES* adapter_addresses = nullptr;
+        for (size_t attempt_no = 0; attempt_no < 3; attempt_no++) {
+
+            // get adapter addresses
+            adapter_addresses = (IP_ADAPTER_ADDRESSES*) malloc(buffer_size);
+            DWORD error;
+            if ((error = GetAdaptersAddresses(
+                        AF_UNSPEC,
+                        GAA_FLAG_SKIP_ANYCAST |
+                        GAA_FLAG_SKIP_MULTICAST |
+                        GAA_FLAG_SKIP_DNS_SERVER |
+                        GAA_FLAG_SKIP_FRIENDLY_NAME,
+                        NULL,
+                        adapter_addresses,
+                        &buffer_size)) == ERROR_SUCCESS) {
+
+                // success
+                break;
+
+            } else if (error == ERROR_BUFFER_OVERFLOW) {
+
+                // retry using new size
+                free(adapter_addresses);
+                adapter_addresses = NULL;
+                continue;
+
+            } else {
+
+                // error - return empty list
+                free(adapter_addresses);
+                return return_addresses;
+            }
+        }
+
+        // now iterate the adapters
+        for (IP_ADAPTER_ADDRESSES* adapter = adapter_addresses; NULL != adapter; adapter = adapter->Next) {
+
+            // check if loopback
+            if (IF_TYPE_SOFTWARE_LOOPBACK == adapter->IfType) {
+                continue;
+            }
+
+            // iterate all IPv4 and IPv6 addresses
+            for (IP_ADAPTER_UNICAST_ADDRESS* adr = adapter->FirstUnicastAddress; adr; adr = adr->Next) {
+                switch (adr->Address.lpSockaddr->sa_family) {
+                    case AF_INET: {
+
+                        // cast address
+                        SOCKADDR_IN* ipv4 = reinterpret_cast<SOCKADDR_IN*>(adr->Address.lpSockaddr);
+
+                        // convert to string
+                        char str_buffer[INET_ADDRSTRLEN] = {0};
+                        inet_ntop(AF_INET, &(ipv4->sin_addr), str_buffer, INET_ADDRSTRLEN);
+
+                        // save result
+                        return_addresses.push_back(str_buffer);
+                        break;
+                    }
+                    case AF_INET6: {
+
+                        // cast address
+                        SOCKADDR_IN6* ipv6 = reinterpret_cast<SOCKADDR_IN6*>(adr->Address.lpSockaddr);
+
+                        // convert to string
+                        char str_buffer[INET6_ADDRSTRLEN] = {0};
+                        inet_ntop(AF_INET6, &(ipv6->sin6_addr), str_buffer, INET6_ADDRSTRLEN);
+                        std::string ipv6_str(str_buffer);
+
+                        // skip non-external addresses
+                        if (!ipv6_str.find("fe")) {
+                            char c = ipv6_str[2];
+                            if (c == '8' || c == '9' || c == 'a' || c == 'b') {
+
+                                // link local address
+                                continue;
+                            }
+                        }
+                        else if (!ipv6_str.find("2001:0:")) {
+
+                            // special use address
+                            continue;
+                        }
+
+                        // save result
+                        return_addresses.push_back(ipv6_str);
+                        break;
+                    }
+                    default: {
+                        continue;
+                    }
+                }
+            }
+        }
+
+        // success
+        free(adapter_addresses);
+        return return_addresses;
+    }
+}