[Qemu-devel] [PATCH v4 2/2] qga: win32 implementation of qmp_guest_network_get_interfaces

[Kirk Allan]

By default, IPv4 prefixes will be derived by matching the address
to those returned by GetAdaptersInfo.  IPv6 prefixes can not be
matched this way due to the unpredictable order of entries.

In Windows Vista/2008 guests and newer, both IPv4 and IPv6 prefixes
can be retrieved from OnLinkPrefixLength.  Setting -–extra-cflags
in the build configuration to ”- D_WIN32_WINNT-0x600 -DWINVER=0x600”
or greater makes OnLinkPrefixLength available.  Setting –-ectra-cflags
is not required and if not set, the default approach to get the prefix
will be taken.

Signed-off-by: Kirk Allan <address@hidden>
---
 qga/commands-win32.c | 220 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 217 insertions(+), 3 deletions(-)

diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 3ef0549..209eba7 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -16,11 +16,17 @@
 #include <powrprof.h>
 #include <stdio.h>
 #include <string.h>
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#include <ws2ipdef.h>
+#include <iptypes.h>
+#include <iphlpapi.h>
 #include "qga/guest-agent-core.h"
 #include "qga/vss-win32.h"
 #include "qga-qmp-commands.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/queue.h"
+#include "qemu/host-utils.h"
 
 #ifndef SHTDN_REASON_FLAG_PLANNED
 #define SHTDN_REASON_FLAG_PLANNED 0x80000000
@@ -589,12 +595,220 @@ void qmp_guest_suspend_hybrid(Error **errp)
     error_set(errp, QERR_UNSUPPORTED);
 }
 
-GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
+static IP_ADAPTER_ADDRESSES *guest_get_adapters_addresses(Error **errp)
 {
-    error_set(errp, QERR_UNSUPPORTED);
+    IP_ADAPTER_ADDRESSES *adptr_addrs = NULL;
+    ULONG adptr_addrs_len = 0;
+    DWORD ret;
+
+    /* Call the first time to get the adptr_addrs_len. */
+    GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_INCLUDE_PREFIX,
+                         NULL, adptr_addrs, &adptr_addrs_len);
+
+    adptr_addrs = g_malloc(adptr_addrs_len);
+    ret = GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_INCLUDE_PREFIX,
+                               NULL, adptr_addrs, &adptr_addrs_len);
+    if (ret != ERROR_SUCCESS) {
+        error_setg_win32(errp, ret, "failed to get adapters addresses");
+        g_free(adptr_addrs);
+        adptr_addrs = NULL;
+    }
+    return adptr_addrs;
+}
+
+static char *guest_wctomb_dup(WCHAR *wstr)
+{
+    char *str;
+    size_t i;
+
+    i = wcslen(wstr) + 1;
+    str = g_malloc(i);
+    WideCharToMultiByte(CP_ACP, WC_COMPOSITECHECK,
+                        wstr, -1, str, i, NULL, NULL);
+    return str;
+}
+
+static char *guest_addr_to_str(IP_ADAPTER_UNICAST_ADDRESS *ip_addr,
+                               Error **errp)
+{
+    char addr_str[INET6_ADDRSTRLEN + INET_ADDRSTRLEN];
+    DWORD len;
+    int ret;
+
+    if (ip_addr->Address.lpSockaddr->sa_family == AF_INET ||
+            ip_addr->Address.lpSockaddr->sa_family == AF_INET6) {
+        len = sizeof(addr_str);
+        ret = WSAAddressToString(ip_addr->Address.lpSockaddr,
+                                 ip_addr->Address.iSockaddrLength,
+                                 NULL,
+                                 addr_str,
+                                 &len);
+        if (ret != 0) {
+            error_setg_win32(errp, WSAGetLastError(),
+                "failed address presentation form conversion");
+            return NULL;
+        }
+        return g_strdup(addr_str);
+    }
     return NULL;
 }
 
+#if (_WIN32_WINNT >= 0x0600)
+static int64_t guest_ip_prefix(IP_ADAPTER_UNICAST_ADDRESS *ip_addr)
+{
+    /* For Windows Vista/2008 and newer, use the OnLinkPrefixLength
+     * field to obtain the prefix.
+     */
+    return ip_addr->OnLinkPrefixLength;
+}
+#else
+/* When using the Windows XP and 2003 build environment, do the best we can to
+ * figure out the prefix.
+ */
+static IP_ADAPTER_INFO *guest_get_adapters_info(void)
+{
+    IP_ADAPTER_INFO *adptr_info = NULL;
+    ULONG adptr_info_len = 0;
+    DWORD ret;
+
+    /* Call the first time to get the adptr_info_len. */
+    GetAdaptersInfo(adptr_info, &adptr_info_len);
+
+    adptr_info = g_malloc(adptr_info_len);
+    ret = GetAdaptersInfo(adptr_info, &adptr_info_len);
+    if (ret != ERROR_SUCCESS) {
+        g_free(adptr_info);
+        adptr_info = NULL;
+    }
+    return adptr_info;
+}
+
+static int64_t guest_ip_prefix(IP_ADAPTER_UNICAST_ADDRESS *ip_addr)
+{
+    int64_t prefix = -1; /* Use for AF_INET6 and unknown/undetermined values. 
*/
+    IP_ADAPTER_INFO *adptr_info, *info;
+    IP_ADDR_STRING *ip;
+    struct in_addr *p;
+
+    if (ip_addr->Address.lpSockaddr->sa_family != AF_INET) {
+        return prefix;
+    }
+    adptr_info = guest_get_adapters_info();
+    if (adptr_info == NULL) {
+        return prefix;
+    }
+
+    /* Match up the passed in ip_addr with one found in adaptr_info.
+     * The matching one in adptr_info will have the netmask.
+     */
+    p = &((struct sockaddr_in *)ip_addr->Address.lpSockaddr)->sin_addr;
+    for (info = adptr_info; info; info = info->Next) {
+        for (ip = &info->IpAddressList; ip; ip = ip->Next) {
+            if (p->S_un.S_addr == inet_addr(ip->IpAddress.String)) {
+                prefix = ctpop32(inet_addr(ip->IpMask.String));
+                goto out;
+            }
+        }
+    }
+out:
+    g_free(adptr_info);
+    return prefix;
+}
+#endif
+
+GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
+{
+    IP_ADAPTER_ADDRESSES *adptr_addrs, *addr;
+    IP_ADAPTER_UNICAST_ADDRESS *ip_addr = NULL;
+    GuestNetworkInterfaceList *head = NULL, *cur_item = NULL;
+    GuestIpAddressList *head_addr, *cur_addr;
+    GuestNetworkInterfaceList *info;
+    GuestIpAddressList *address_item = NULL;
+    unsigned char *mac_addr;
+    char *addr_str;
+    WORD wsa_version;
+    WSADATA wsa_data;
+    int ret;
+
+    adptr_addrs = guest_get_adapters_addresses(errp);
+    if (adptr_addrs == NULL) {
+        return NULL;
+    }
+
+    /* Make WSA APIs available. */
+    wsa_version = MAKEWORD(2, 2);
+    ret = WSAStartup(wsa_version, &wsa_data);
+    if (ret != 0) {
+        error_setg_win32(errp, ret, "failed socket startup");
+        goto out;
+    }
+
+    for (addr = adptr_addrs; addr; addr = addr->Next) {
+        info = g_malloc0(sizeof(*info));
+
+        if (cur_item == NULL) {
+            head = cur_item = info;
+        } else {
+            cur_item->next = info;
+            cur_item = info;
+        }
+
+        info->value = g_malloc0(sizeof(*info->value));
+        info->value->name = guest_wctomb_dup(addr->FriendlyName);
+
+        if (addr->PhysicalAddressLength != 0) {
+            mac_addr = addr->PhysicalAddress;
+
+            info->value->hardware_address =
+                g_strdup_printf("%02x:%02x:%02x:%02x:%02x:%02x",
+                                (int) mac_addr[0], (int) mac_addr[1],
+                                (int) mac_addr[2], (int) mac_addr[3],
+                                (int) mac_addr[4], (int) mac_addr[5]);
+
+            info->value->has_hardware_address = true;
+        }
+
+        head_addr = NULL;
+        cur_addr = NULL;
+        for (ip_addr = addr->FirstUnicastAddress;
+                ip_addr;
+                ip_addr = ip_addr->Next) {
+            addr_str = guest_addr_to_str(ip_addr, errp);
+            if (addr_str == NULL) {
+                continue;
+            }
+
+            address_item = g_malloc0(sizeof(*address_item));
+
+            if (!cur_addr) {
+                head_addr = cur_addr = address_item;
+            } else {
+                cur_addr->next = address_item;
+                cur_addr = address_item;
+            }
+
+            address_item->value = g_malloc0(sizeof(*address_item->value));
+            address_item->value->ip_address = addr_str;
+            address_item->value->prefix = guest_ip_prefix(ip_addr);
+            if (ip_addr->Address.lpSockaddr->sa_family == AF_INET) {
+                address_item->value->ip_address_type =
+                    GUEST_IP_ADDRESS_TYPE_IPV4;
+            } else if (ip_addr->Address.lpSockaddr->sa_family == AF_INET6) {
+                address_item->value->ip_address_type =
+                    GUEST_IP_ADDRESS_TYPE_IPV6;
+            }
+        }
+        if (head_addr) {
+            info->value->has_ip_addresses = true;
+            info->value->ip_addresses = head_addr;
+        }
+    }
+    WSACleanup();
+out:
+    g_free(adptr_addrs);
+    return head;
+}
+
 int64_t qmp_guest_get_time(Error **errp)
 {
     SYSTEMTIME ts = {0};
@@ -707,7 +921,7 @@ GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error 
**errp)
 GList *ga_command_blacklist_init(GList *blacklist)
 {
     const char *list_unsupported[] = {
-        "guest-suspend-hybrid", "guest-network-get-interfaces",
+        "guest-suspend-hybrid",
         "guest-get-vcpus", "guest-set-vcpus",
         "guest-set-user-password",
         "guest-get-memory-blocks", "guest-set-memory-blocks",
-- 
1.8.5.6