Zebediah Figura : dnsapi: Return a double-null-terminated string from DnsQueryConfig(DnsConfigSearchList).

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 23d85e6e9ab0b7f0f79beb41fe6738c50d02d632
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=23d85e6e9ab0b7f0f79beb41f...

Author: Zebediah Figura 
Date:   Fri Jun 24 15:33:42 2022 -0500

dnsapi: Return a double-null-terminated string from DnsQueryConfig(DnsConfigSearchList).

DNS_TEXT_DATA contains pointers and is thus not WoW64 compatible. Since the API
is internal to Wine, use a simpler format instead of fixing our WoW64
translation.

The problem was found by Brendan Shanks; this solution was suggested by Hans Leidekker.

---

dlls/dnsapi/dnsapi.h          |  2 +-
 dlls/dnsapi/libresolv.c       | 21 ++++++++-------------
 dlls/iphlpapi/iphlpapi_main.c |  6 +++---
 3 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/dlls/dnsapi/dnsapi.h b/dlls/dnsapi/dnsapi.h
index f27cce9a99d..a81cb712f3e 100644
--- a/dlls/dnsapi/dnsapi.h
+++ b/dlls/dnsapi/dnsapi.h
@@ -128,7 +128,7 @@ extern const char *debugstr_type( unsigned short ) DECLSPEC_HIDDEN;

struct get_searchlist_params
 {
-    DNS_TXT_DATAW   *list;
+    WCHAR           *list;
     DWORD           *len;
 };

diff --git a/dlls/dnsapi/libresolv.c b/dlls/dnsapi/libresolv.c
index 51a44f88aa5..fd645d53fd7 100644
--- a/dlls/dnsapi/libresolv.c
+++ b/dlls/dnsapi/libresolv.c
@@ -125,16 +125,15 @@ static DNS_STATUS map_h_errno( int error )
 static NTSTATUS resolv_get_searchlist( void *args )
 {
     const struct get_searchlist_params *params = args;
-    DNS_TXT_DATAW *list = params->list;
-    DWORD i, needed, str_needed = 0;
+    WCHAR *list = params->list;
+    DWORD i, needed = 0;
     WCHAR *ptr, *end;

init_resolver();

for (i = 0; i < MAXDNSRCH + 1 && _res.dnsrch[i]; i++)
-        str_needed += (strlen(_res.dnsrch[i]) + 1) * sizeof(WCHAR);
-
-    needed = FIELD_OFFSET(DNS_TXT_DATAW, pStringArray[i]) + str_needed;
+        needed += (strlen(_res.dnsrch[i]) + 1) * sizeof(WCHAR);
+    needed += sizeof(WCHAR); /* null terminator */

if (!list || *params->len < needed)
     {
@@ -143,16 +142,12 @@ static NTSTATUS resolv_get_searchlist( void *args )
     }

*params->len = needed;
-    list->dwStringCount = i;

-    ptr = (WCHAR *)(list->pStringArray + i);
-    end = ptr + str_needed / sizeof(WCHAR);
+    ptr = list;
+    end = ptr + needed / sizeof(WCHAR);
     for (i = 0; i < MAXDNSRCH + 1 && _res.dnsrch[i]; i++)
-    {
-        list->pStringArray[i] = ptr;
-        ptr += ntdll_umbstowcs( _res.dnsrch[i], strlen(_res.dnsrch[i]) + 1,
-                                list->pStringArray[i], end - ptr );
-    }
+        ptr += ntdll_umbstowcs( _res.dnsrch[i], strlen(_res.dnsrch[i]) + 1, ptr, end - ptr );
+    *ptr = 0; /* null terminator */
     return ERROR_SUCCESS;
 }

diff --git a/dlls/iphlpapi/iphlpapi_main.c b/dlls/iphlpapi/iphlpapi_main.c
index 65d3793011b..a95a581532f 100644
--- a/dlls/iphlpapi/iphlpapi_main.c
+++ b/dlls/iphlpapi/iphlpapi_main.c
@@ -1138,7 +1138,7 @@ static DWORD dns_info_alloc( IP_ADAPTER_ADDRESSES *aa, ULONG family, ULONG flags
     DWORD err, i, size, attempt, sockaddr_len;
     WCHAR name[MAX_ADAPTER_NAME_LENGTH + 1];
     DNS_ADDR_ARRAY *servers;
-    DNS_TXT_DATAW *search;
+    WCHAR *search;

while (aa)
     {
@@ -1192,9 +1192,9 @@ static DWORD dns_info_alloc( IP_ADAPTER_ADDRESSES *aa, ULONG family, ULONG flags
             (search = heap_alloc( size )))
         {
             if (!DnsQueryConfig( DnsConfigSearchList, 0, name, NULL, search, &size ) &&
-                search->dwStringCount && wcslen( search->pStringArray[0] ) < MAX_DNS_SUFFIX_STRING_LENGTH)
+                search[0] && wcslen( search ) < MAX_DNS_SUFFIX_STRING_LENGTH)
             {
-                wcscpy( aa->DnsSuffix, search->pStringArray[0] );
+                wcscpy( aa->DnsSuffix, search );
             }
             heap_free( search );
         }