[PATCH v7 1/4] ntdll: Implement NtQuerySystemEnvironmentValueEx.

[Grigory Vasilyev]

From: Grigory Vasilyev

---
 dlls/ntdll/unix/system.c | 72 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 70 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/unix/system.c b/dlls/ntdll/unix/system.c
index f47925018b8..68149bfad6c 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 +3683,76 @@ NTSTATUS WINAPI NtQuerySystemEnvironmentValue( UNICODE_STRING *name, WCHAR *buff
 NTSTATUS WINAPI NtQuerySystemEnvironmentValueEx( UNICODE_STRING *name, GUID *vendor, void *buffer,
                                                  ULONG *retlen, ULONG *attrib )
 {
-    FIXME( "(%s, %s, %p, %p, %p), stub\n", debugstr_us(name),
-           debugstr_guid(vendor), buffer, retlen, attrib );
+#if defined(__linux__) || defined(__gnu_linux__)
+    int fd, rc;
+    size_t bytes, pos = 0;
+    ssize_t ssz;
+    char filename[256];
+    char *cname;
+    struct stat stat_info = {0};
+
+    if(!name || !vendor || !attrib){
+        return ERROR_INVALID_PARAMETER;
+    }
+
+    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, &stat_info);
+    if (rc < 0 || stat_info.st_size == 0)
+        goto done;
+
+try_read_attributes:
+    ssz = read(fd, attrib, 4);
+    if (ssz < 0)
+    {
+        if (errno == EAGAIN || errno == EINTR)
+            goto try_read_attributes;
+        goto done;
+    }
+
+    if(buffer && retlen)
+    {
+        if (stat_info.st_size - 4 < *retlen)
+            bytes = stat_info.st_size - 4;
+        else
+            bytes = *retlen;
+        while (pos < bytes)
+        {
+            ssz = read(fd, (char *) buffer + pos, bytes - pos);
+            if (ssz < 0)
+            {
+                if (errno == EAGAIN || errno == EINTR)
+                    continue;
+                goto done;
+            }
+            pos += ssz;
+        }
+        *retlen = ssz & 0xFFFFFFFF;
+    } 
+
+    close(fd);
+    return STATUS_SUCCESS;
+
+done:
+    if (fd >= 0)
+        close(fd);
+    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
 }