libcli/smb: make smb2cli_ioctl_parse_buffer() available as smb2cli_parse_dyn_buffer()

[kseeger/samba-autobuild-v4-15-test/.git] / libcli / smb / smbXcli_base.c

diff --git a/libcli/smb/smbXcli_base.c b/libcli/smb/smbXcli_base.c
index 341a371d8b819b7170c7507f07eb9bb06b3871fc..3fb51e33ffe34f6622cc8338c0361cf3c89475a1 100644 (file)
--- a/libcli/smb/smbXcli_base.c
+++ b/libcli/smb/smbXcli_base.c
@@ -6823,3 +6823,94 @@ uint64_t smb2cli_conn_get_mid(struct smbXcli_conn *conn)
 {
        return conn->smb2.mid;
 }
+
+NTSTATUS smb2cli_parse_dyn_buffer(uint32_t dyn_offset,
+                                 const DATA_BLOB dyn_buffer,
+                                 uint32_t min_offset,
+                                 uint32_t buffer_offset,
+                                 uint32_t buffer_length,
+                                 uint32_t max_length,
+                                 uint32_t *next_offset,
+                                 DATA_BLOB *buffer)
+{
+       uint32_t offset;
+       bool oob;
+
+       *buffer = data_blob_null;
+       *next_offset = dyn_offset;
+
+       if (buffer_offset == 0) {
+               /*
+                * If the offset is 0, we better ignore
+                * the buffer_length field.
+                */
+               return NT_STATUS_OK;
+       }
+
+       if (buffer_length == 0) {
+               /*
+                * If the length is 0, we better ignore
+                * the buffer_offset field.
+                */
+               return NT_STATUS_OK;
+       }
+
+       if ((buffer_offset % 8) != 0) {
+               /*
+                * The offset needs to be 8 byte aligned.
+                */
+               return NT_STATUS_INVALID_NETWORK_RESPONSE;
+       }
+
+       /*
+        * We used to enforce buffer_offset to be
+        * an exact match of the expected minimum,
+        * but the NetApp Ontap 7.3.7 SMB server
+        * gets the padding wrong and aligns the
+        * input_buffer_offset by a value of 8.
+        *
+        * So we just enforce that the offset is
+        * not lower than the expected value.
+        */
+       SMB_ASSERT(min_offset >= dyn_offset);
+       if (buffer_offset < min_offset) {
+               return NT_STATUS_INVALID_NETWORK_RESPONSE;
+       }
+
+       /*
+        * Make [input|output]_buffer_offset relative to "dyn_buffer"
+        */
+       offset = buffer_offset - dyn_offset;
+       oob = smb_buffer_oob(dyn_buffer.length, offset, buffer_length);
+       if (oob) {
+               return NT_STATUS_INVALID_NETWORK_RESPONSE;
+       }
+
+       /*
+        * Give the caller a hint what we consumed,
+        * the caller may need to add possible padding.
+        */
+       *next_offset = buffer_offset + buffer_length;
+
+       if (max_length == 0) {
+               /*
+                * If max_input_length is 0 we ignore the
+                * input_buffer_length, because Windows 2008 echos the
+                * DCERPC request from the requested input_buffer to
+                * the response input_buffer.
+                *
+                * We just use the same logic also for max_output_length...
+                */
+               buffer_length = 0;
+       }
+
+       if (buffer_length > max_length) {
+               return NT_STATUS_INVALID_NETWORK_RESPONSE;
+       }
+
+       *buffer = (DATA_BLOB) {
+               .data = dyn_buffer.data + offset,
+               .length = buffer_length,
+       };
+       return NT_STATUS_OK;
+}