[PATCH v4 1/4] ntdll: Implement NtQuerySystemEnvironmentValueEx.

[Grigory Vasilyev]

From: Grigory Vasilyev

---
 dlls/ntdll/unix/system.c | 59 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/dlls/ntdll/unix/system.c b/dlls/ntdll/unix/system.c
index f47925018b8..0d3a4f403ef 100644
--- a/dlls/ntdll/unix/system.c
+++ b/dlls/ntdll/unix/system.c
@@ -30,6 +30,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <errno.h>
@@ -3682,9 +3683,67 @@ NTSTATUS WINAPI NtQuerySystemEnvironmentValue( UNICODE_STRING *name, WCHAR *buff
 NTSTATUS WINAPI NtQuerySystemEnvironmentValueEx( UNICODE_STRING *name, GUID *vendor, void *buffer,
                                                  ULONG *retlen, ULONG *attrib )
 {
+#if defined(__linux__) || defined(__gnu_linux__)
+    int fd, rc;
+    size_t bytes, pos = 0;
+    ssize_t ssz;
+    char filename[128];
+    char *cname;
+    struct stat sb = { 0 };
+
+    cname = (char *)malloc( name->Length );
+    ntdll_wcstoumbs( name->Buffer, name->Length, cname, name->Length, FALSE );
+
+    snprintf( filename, sizeof(filename), "/sys/firmware/efi/efivars/%s-%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+            cname, vendor->Data1, vendor->Data2, vendor->Data3,
+            vendor->Data4[0], vendor->Data4[1], vendor->Data4[2], vendor->Data4[3],
+            vendor->Data4[4], vendor->Data4[5], vendor->Data4[6], vendor->Data4[7]);
+
+    fd = open( filename, O_RDONLY | O_NONBLOCK );
+    if (fd < 0)
+        goto done;
+
+    rc = fstat( fd, &sb );
+    if ( rc < 0 || sb.st_size == 0 )
+        goto done;
+
+    if ( sb.st_size - 4 < *retlen )
+        bytes = sb.st_size - 4;
+    else
+        bytes = *retlen;
+
+try_read_attributes:
+    ssz = read( fd, attrib, 4 );
+    if ( ssz < 0 ) {
+        if ( errno == EAGAIN || errno == EINTR )
+            goto try_read_attributes;
+        goto done;
+    }
+
+    while ( pos < bytes ) {
+        ssz = read( fd, (char *) buffer + pos, bytes - pos );
+        if ( ssz < 0 ) {
+            if ( errno == EAGAIN || errno == EINTR )
+                continue;
+            goto done;
+        }
+        pos += ssz;
+    }
+
+    close( fd );
+    *retlen = ssz & 0xFFFFFFFF;
+    return STATUS_SUCCESS;
+
+done:
+    if ( fd >= 0 )
+        close( fd );
+    *retlen = 0;
+    return STATUS_UNSUCCESSFUL;
+#else
     FIXME( "(%s, %s, %p, %p, %p), stub\n", debugstr_us(name),
            debugstr_guid(vendor), buffer, retlen, attrib );
     return STATUS_NOT_IMPLEMENTED;
+#endif
 }