drivers/net/pcap/pcap_osdep_windows.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright (c) 2021 Dmitry Kozlyuk
   3  */
   4
   5 #include <winsock2.h>
   6 #include <iphlpapi.h>
   7 #include <strsafe.h>
   8
   9 #include "pcap_osdep.h"
  10
  11 /*
  12  * Given a device name like "\Device\NPF_{GUID}" extract the "{GUID}" part.
  13  * Return NULL if "{GUID}" part is not found.
  14  */
  15 static const char *
  16 iface_guid(const char *name)
  17 {
  18         static const size_t GUID_LENGTH = 32 + 4; /* 16 hex bytes + 4 dashes */
  19
  20         const char *ob, *cb;
  21
  22         ob = strchr(name, '{');
  23         if (ob == NULL)
  24                 return NULL;
  25
  26         cb = strchr(ob, '}');
  27         if (cb == NULL || cb - ob != GUID_LENGTH + 1) /* + 1 opening '{' */
  28                 return NULL;
  29
  30         return ob;
  31 }
  32
  33 /*
  34  * libpcap takes device names like "\Device\NPF_{GUID}",
  35  * GetAdapterIndex() takes interface names like "\DEVICE\TCPIP_{GUID}".
  36  * Try to convert, fall back to original device name.
  37  */
  38 int
  39 osdep_iface_index_get(const char *device_name)
  40 {
  41         WCHAR adapter_name[MAX_ADAPTER_NAME_LENGTH];
  42         const char *guid;
  43         ULONG index;
  44         DWORD ret;
  45
  46         guid = iface_guid(device_name);
  47         if (guid != NULL)
  48                 StringCbPrintfW(adapter_name, sizeof(adapter_name),
  49                         L"\\DEVICE\\TCPIP_%S", guid);
  50         else
  51                 StringCbPrintfW(adapter_name, sizeof(adapter_name),
  52                         L"%S", device_name);
  53
  54         ret = GetAdapterIndex(adapter_name, &index);
  55         if (ret != NO_ERROR) {
  56                 PMD_LOG(ERR, "GetAdapterIndex(%S) = %lu\n", adapter_name, ret);
  57                 return -1;
  58         }
  59
  60         return index;
  61 }
  62
  63 /*
  64  * libpcap takes device names like "\Device\NPF_{GUID}",
  65  * GetAdaptersAddresses() returns names in "{GUID}" form.
  66  * Try to extract GUID from device name, fall back to original device name.
  67  */
  68 int
  69 osdep_iface_mac_get(const char *device_name, struct rte_ether_addr *mac)
  70 {
  71         IP_ADAPTER_ADDRESSES *info = NULL, *cur = NULL;
  72         ULONG size, sys_ret;
  73         const char *adapter_name;
  74         int ret = -1;
  75
  76         sys_ret = GetAdaptersAddresses(AF_UNSPEC, 0, NULL, NULL, &size);
  77         if (sys_ret != ERROR_BUFFER_OVERFLOW) {
  78                 PMD_LOG(ERR, "GetAdapterAddresses() = %lu, expected %lu\n",
  79                         sys_ret, ERROR_BUFFER_OVERFLOW);
  80                 return -1;
  81         }
  82
  83         info = (IP_ADAPTER_ADDRESSES *)malloc(size);
  84         if (info == NULL) {
  85                 PMD_LOG(ERR, "Cannot allocate adapter address info\n");
  86                 return -1;
  87         }
  88
  89         sys_ret = GetAdaptersAddresses(AF_UNSPEC, 0, NULL, info, &size);
  90         if (sys_ret != ERROR_SUCCESS) {
  91                 PMD_LOG(ERR, "GetAdapterAddresses() = %lu\n", sys_ret);
  92                 free(info);
  93                 return -1;
  94         }
  95
  96         adapter_name = iface_guid(device_name);
  97         if (adapter_name == NULL)
  98                 adapter_name = device_name;
  99
 100         for (cur = info; cur != NULL; cur = cur->Next) {
 101                 if (strcmp(cur->AdapterName, adapter_name) == 0) {
 102                         if (cur->PhysicalAddressLength != RTE_ETHER_ADDR_LEN) {
 103                                 PMD_LOG(ERR, "Physical address length: want %u, got %lu",
 104                                         RTE_ETHER_ADDR_LEN,
 105                                         cur->PhysicalAddressLength);
 106                                 break;
 107                         }
 108
 109                         memcpy(mac->addr_bytes, cur->PhysicalAddress,
 110                                 RTE_ETHER_ADDR_LEN);
 111                         ret = 0;
 112                         break;
 113                 }
 114         }
 115
 116         free(info);
 117         return ret;
 118 }