From d2083a1aed38008cb8d01e465bb035449f0547ca Mon Sep 17 00:00:00 2001
From: Michael Jumper <mjumper@apache.org>
Date: Sun, 29 Dec 2019 18:04:27 -0800
Subject: [PATCH] GUACAMOLE-249: Refactor RDPDR to be more documentable.
 Document RDPDR fully.

---
 .../rdpdr/rdpdr-fs-messages-dir-info.c        |  53 ++---
 .../rdpdr/rdpdr-fs-messages-dir-info.h        |  44 +++--
 .../rdpdr/rdpdr-fs-messages-file-info.c       | 124 ++++++------
 .../rdpdr/rdpdr-fs-messages-file-info.h       |  64 ++++---
 .../rdpdr/rdpdr-fs-messages-vol-info.c        |  57 +++---
 .../rdpdr/rdpdr-fs-messages-vol-info.h        |  20 +-
 .../rdp/channels/rdpdr/rdpdr-fs-messages.c    | 181 ++++++++----------
 .../rdp/channels/rdpdr/rdpdr-fs-messages.h    |  49 ++---
 src/protocols/rdp/channels/rdpdr/rdpdr-fs.c   |  54 +++---
 src/protocols/rdp/channels/rdpdr/rdpdr-fs.h   |  10 +
 .../rdp/channels/rdpdr/rdpdr-messages.c       |  81 ++++++--
 .../rdp/channels/rdpdr/rdpdr-messages.h       | 105 ++++++++--
 .../rdp/channels/rdpdr/rdpdr-printer.c        |  40 ++--
 .../rdp/channels/rdpdr/rdpdr-printer.h        |  39 ++++
 src/protocols/rdp/channels/rdpdr/rdpdr.h      |  97 +++++++++-
 15 files changed, 625 insertions(+), 393 deletions(-)

diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.c b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.c
index 256ac14a..25d355f5 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.c
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.c
@@ -18,6 +18,7 @@
  */
 
 #include "config.h"
+#include "channels/rdpdr/rdpdr-fs-messages-dir-info.h"
 #include "channels/rdpdr/rdpdr.h"
 #include "fs.h"
 #include "unicode.h"
@@ -29,8 +30,8 @@
 #include <stddef.h>
 
 void guac_rdpdr_fs_process_query_directory_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        const char* entry_name, int entry_file_id) {
 
     guac_rdp_fs_file* file;
 
@@ -43,16 +44,17 @@ void guac_rdpdr_fs_process_query_directory_info(guac_rdp_common_svc* svc,
             (char*) utf16_entry_name, sizeof(utf16_entry_name));
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, entry_file_id);
     if (file == NULL)
         return;
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i (entry_name=\"%s\")]",
-            __func__, file_id, entry_name);
+            __func__, entry_file_id, entry_name);
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 4 + 64 + utf16_length + 2);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS,
+            4 + 64 + utf16_length + 2);
 
     Stream_Write_UINT32(output_stream,
             64 + utf16_length + 2); /* Length */
@@ -76,8 +78,8 @@ void guac_rdpdr_fs_process_query_directory_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_full_directory_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        const char* entry_name, int entry_file_id) {
 
     guac_rdp_fs_file* file;
 
@@ -90,16 +92,17 @@ void guac_rdpdr_fs_process_query_full_directory_info(guac_rdp_common_svc* svc,
             (char*) utf16_entry_name, sizeof(utf16_entry_name));
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, entry_file_id);
     if (file == NULL)
         return;
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i (entry_name=\"%s\")]",
-            __func__, file_id, entry_name);
+            __func__, entry_file_id, entry_name);
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 4 + 68 + utf16_length + 2);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS,
+            4 + 68 + utf16_length + 2);
 
     Stream_Write_UINT32(output_stream,
             68 + utf16_length + 2); /* Length */
@@ -124,8 +127,8 @@ void guac_rdpdr_fs_process_query_full_directory_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_both_directory_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        const char* entry_name, int entry_file_id) {
 
     guac_rdp_fs_file* file;
 
@@ -138,16 +141,17 @@ void guac_rdpdr_fs_process_query_both_directory_info(guac_rdp_common_svc* svc,
             (char*) utf16_entry_name, sizeof(utf16_entry_name));
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, entry_file_id);
     if (file == NULL)
         return;
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i (entry_name=\"%s\")]",
-            __func__, file_id, entry_name);
+            __func__, entry_file_id, entry_name);
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 4 + 69 + 24 + utf16_length + 2);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS,
+            4 + 69 + 24 + utf16_length + 2);
 
     Stream_Write_UINT32(output_stream,
             69 + 24 + utf16_length + 2); /* Length */
@@ -176,8 +180,8 @@ void guac_rdpdr_fs_process_query_both_directory_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_names_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        const char* entry_name, int entry_file_id) {
 
     guac_rdp_fs_file* file;
 
@@ -190,16 +194,17 @@ void guac_rdpdr_fs_process_query_names_info(guac_rdp_common_svc* svc,
             (char*) utf16_entry_name, sizeof(utf16_entry_name));
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, entry_file_id);
     if (file == NULL)
         return;
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i (entry_name=\"%s\")]",
-            __func__, file_id, entry_name);
+            __func__, entry_file_id, entry_name);
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 4 + 12 + utf16_length + 2);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS,
+            4 + 12 + utf16_length + 2);
 
     Stream_Write_UINT32(output_stream,
             12 + utf16_length + 2); /* Length */
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.h b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.h
index 8bb4ac68..c4b0f8ad 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-dir-info.h
@@ -34,40 +34,60 @@
 
 #include <winpr/stream.h>
 
+/**
+ * Handler for Device I/O Requests which query information about the files
+ * within a directory.
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ *
+ * @param device
+ *     The guac_rdpdr_device of the relevant device, as dictated by the
+ *     deviceId field of common RDPDR header within the received PDU. Within
+ *     the guac_rdpdr_iorequest structure, the deviceId field is stored within
+ *     device_id.
+ *
+ * @param iorequest
+ *     The contents of the common RDPDR Device I/O Request header shared by all
+ *     RDPDR devices.
+ *
+ * @param entry_name
+ *     The filename of the file being queried.
+ *
+ * @param entry_file_id
+ *     The ID of the file being queried.
+ */
+typedef void guac_rdpdr_directory_query_handler(guac_rdp_common_svc* svc,
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        const char* entry_name, int entry_file_id);
+
 /**
  * Processes a query request for FileDirectoryInformation. From the
  * documentation this is "defined as the file's name, time stamp, and size, or its
  * attributes."
  */
-void guac_rdpdr_fs_process_query_directory_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id);
+guac_rdpdr_directory_query_handler guac_rdpdr_fs_process_query_directory_info;
 
 /**
  * Processes a query request for FileFullDirectoryInformation. From the
  * documentation, this is "defined as all the basic information, plus extended
  * attribute size."
  */
-void guac_rdpdr_fs_process_query_full_directory_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id);
+guac_rdpdr_directory_query_handler guac_rdpdr_fs_process_query_full_directory_info;
 
 /**
  * Processes a query request for FileBothDirectoryInformation. From the
  * documentation, this absurdly-named request is "basic information plus
  * extended attribute size and short name about a file or directory."
  */
-void guac_rdpdr_fs_process_query_both_directory_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id);
+guac_rdpdr_directory_query_handler guac_rdpdr_fs_process_query_both_directory_info;
 
 /**
  * Processes a query request for FileNamesInformation. From the documentation,
  * this is "detailed information on the names of files in a directory."
  */
-void guac_rdpdr_fs_process_query_names_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, const char* entry_name, int file_id,
-        int completion_id);
+guac_rdpdr_directory_query_handler guac_rdpdr_fs_process_query_names_info;
 
 #endif
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.c b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.c
index 4629ca59..509087b8 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.c
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.c
@@ -18,6 +18,7 @@
  */
 
 #include "config.h"
+#include "channels/rdpdr/rdpdr-fs-messages-file-info.h"
 #include "channels/rdpdr/rdpdr.h"
 #include "fs.h"
 #include "unicode.h"
@@ -31,23 +32,22 @@
 #include <string.h>
 
 void guac_rdpdr_fs_process_query_basic_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream;
     guac_rdp_fs_file* file;
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, iorequest->file_id);
     if (file == NULL)
         return;
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 40);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS, 40);
 
     Stream_Write_UINT32(output_stream, 36);
     Stream_Write_UINT64(output_stream, file->ctime);      /* CreationTime   */
@@ -63,27 +63,26 @@ void guac_rdpdr_fs_process_query_basic_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_standard_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream;
     guac_rdp_fs_file* file;
     BOOL is_directory = FALSE;
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, iorequest->file_id);
     if (file == NULL)
         return;
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
     if (file->attributes & FILE_ATTRIBUTE_DIRECTORY)
         is_directory = TRUE;
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 26);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS, 26);
 
     Stream_Write_UINT32(output_stream, 22);
     Stream_Write_UINT64(output_stream, file->size);   /* AllocationSize */
@@ -99,23 +98,22 @@ void guac_rdpdr_fs_process_query_standard_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_attribute_tag_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream;
     guac_rdp_fs_file* file;
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, iorequest->file_id);
     if (file == NULL)
         return;
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 12);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS, 12);
 
     Stream_Write_UINT32(output_stream, 8);
     Stream_Write_UINT32(output_stream, file->attributes); /* FileAttributes */
@@ -128,8 +126,8 @@ void guac_rdpdr_fs_process_query_attribute_tag_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_set_rename_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        int length, wStream* input_stream) {
 
     int result;
     int filename_length;
@@ -145,9 +143,9 @@ void guac_rdpdr_fs_process_set_rename_info(guac_rdp_common_svc* svc,
     guac_rdp_utf16_to_utf8(Stream_Pointer(input_stream), filename_length/2,
             destination_path, sizeof(destination_path));
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i] destination_path=\"%s\"",
-            __func__, file_id, destination_path);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]"
+            "destination_path=\"%s\"", __func__, iorequest->file_id,
+            destination_path);
 
     /* If file moving to \Download folder, start stream, do not move */
     if (strncmp(destination_path, "\\Download\\", 10) == 0) {
@@ -155,28 +153,28 @@ void guac_rdpdr_fs_process_set_rename_info(guac_rdp_common_svc* svc,
         guac_rdp_fs_file* file;
 
         /* Get file */
-        file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+        file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, iorequest->file_id);
         if (file == NULL)
             return;
 
         /* Initiate download, pretend move succeeded */
         guac_rdpdr_start_download(svc, device, file->absolute_path);
         output_stream = guac_rdpdr_new_io_completion(device,
-                completion_id, STATUS_SUCCESS, 4);
+                iorequest->completion_id, STATUS_SUCCESS, 4);
 
     }
 
     /* Otherwise, rename as requested */
     else {
 
-        result = guac_rdp_fs_rename((guac_rdp_fs*) device->data, file_id,
-                destination_path);
+        result = guac_rdp_fs_rename((guac_rdp_fs*) device->data,
+                iorequest->file_id, destination_path);
         if (result < 0)
             output_stream = guac_rdpdr_new_io_completion(device,
-                    completion_id, guac_rdp_fs_get_status(result), 4);
+                    iorequest->completion_id, guac_rdp_fs_get_status(result), 4);
         else
             output_stream = guac_rdpdr_new_io_completion(device,
-                    completion_id, STATUS_SUCCESS, 4);
+                    iorequest->completion_id, STATUS_SUCCESS, 4);
 
     }
 
@@ -186,8 +184,8 @@ void guac_rdpdr_fs_process_set_rename_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_set_allocation_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        int length, wStream* input_stream) {
 
     int result;
     UINT64 size;
@@ -196,18 +194,17 @@ void guac_rdpdr_fs_process_set_allocation_info(guac_rdp_common_svc* svc,
     /* Read new size */
     Stream_Read_UINT64(input_stream, size); /* AllocationSize */
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i] size=%" PRIu64,
-            __func__, file_id, (uint64_t) size);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i] "
+            "size=%" PRIu64, __func__, iorequest->file_id, (uint64_t) size);
 
     /* Truncate file */
-    result = guac_rdp_fs_truncate((guac_rdp_fs*) device->data, file_id, size);
+    result = guac_rdp_fs_truncate((guac_rdp_fs*) device->data, iorequest->file_id, size);
     if (result < 0)
         output_stream = guac_rdpdr_new_io_completion(device,
-                completion_id, guac_rdp_fs_get_status(result), 4);
+                iorequest->completion_id, guac_rdp_fs_get_status(result), 4);
     else
         output_stream = guac_rdpdr_new_io_completion(device,
-                completion_id, STATUS_SUCCESS, 4);
+                iorequest->completion_id, STATUS_SUCCESS, 4);
 
     Stream_Write_UINT32(output_stream, length);
     guac_rdp_common_svc_write(svc, output_stream);
@@ -215,23 +212,22 @@ void guac_rdpdr_fs_process_set_allocation_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_set_disposition_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        int length, wStream* input_stream) {
 
     wStream* output_stream;
 
     /* Delete file */
-    int result = guac_rdp_fs_delete((guac_rdp_fs*) device->data, file_id);
+    int result = guac_rdp_fs_delete((guac_rdp_fs*) device->data, iorequest->file_id);
     if (result < 0)
         output_stream = guac_rdpdr_new_io_completion(device,
-                completion_id, guac_rdp_fs_get_status(result), 4);
+                iorequest->completion_id, guac_rdp_fs_get_status(result), 4);
     else
         output_stream = guac_rdpdr_new_io_completion(device,
-                completion_id, STATUS_SUCCESS, 4);
+                iorequest->completion_id, STATUS_SUCCESS, 4);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
     Stream_Write_UINT32(output_stream, length);
 
@@ -240,8 +236,8 @@ void guac_rdpdr_fs_process_set_disposition_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_set_end_of_file_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        int length, wStream* input_stream) {
 
     int result;
     UINT64 size;
@@ -250,18 +246,17 @@ void guac_rdpdr_fs_process_set_end_of_file_info(guac_rdp_common_svc* svc,
     /* Read new size */
     Stream_Read_UINT64(input_stream, size); /* AllocationSize */
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i] size=%" PRIu64,
-            __func__, file_id, (uint64_t) size);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i] "
+            "size=%" PRIu64, __func__, iorequest->file_id, (uint64_t) size);
 
     /* Truncate file */
-    result = guac_rdp_fs_truncate((guac_rdp_fs*) device->data, file_id, size);
+    result = guac_rdp_fs_truncate((guac_rdp_fs*) device->data, iorequest->file_id, size);
     if (result < 0)
         output_stream = guac_rdpdr_new_io_completion(device,
-                completion_id, guac_rdp_fs_get_status(result), 4);
+                iorequest->completion_id, guac_rdp_fs_get_status(result), 4);
     else
         output_stream = guac_rdpdr_new_io_completion(device,
-                completion_id, STATUS_SUCCESS, 4);
+                iorequest->completion_id, STATUS_SUCCESS, 4);
 
     Stream_Write_UINT32(output_stream, length);
     guac_rdp_common_svc_write(svc, output_stream);
@@ -269,18 +264,17 @@ void guac_rdpdr_fs_process_set_end_of_file_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_set_basic_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        int length, wStream* input_stream) {
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 4);
+            iorequest->completion_id, STATUS_SUCCESS, 4);
 
     /* Currently do nothing, just respond */
     Stream_Write_UINT32(output_stream, length);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i] IGNORED",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i] IGNORED",
+            __func__, iorequest->file_id);
 
     guac_rdp_common_svc_write(svc, output_stream);
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.h b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.h
index d2198f5d..dfd207ae 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-file-info.h
@@ -33,72 +33,88 @@
 
 #include <winpr/stream.h>
 
+/**
+ * Handler for Device I/O Requests which set/update file information.
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ *
+ * @param device
+ *     The guac_rdpdr_device of the relevant device, as dictated by the
+ *     deviceId field of common RDPDR header within the received PDU. Within
+ *     the guac_rdpdr_iorequest structure, the deviceId field is stored within
+ *     device_id.
+ *
+ * @param iorequest
+ *     The contents of the common RDPDR Device I/O Request header shared by all
+ *     RDPDR devices.
+ *
+ * @param length
+ *     The length of the SetBuffer field of the I/O request, in bytes. Whether
+ *     the SetBuffer field is applicable to a particular request, as well as
+ *     the specific contents of that field, depend on the type of request.
+ *
+ * @param input_stream
+ *     The remaining data within the received PDU, following the common RDPDR
+ *     Device I/O Request header and length field. If the SetBuffer field is
+ *     used for this request, the first byte of SetBuffer will be the first
+ *     byte read from this stream.
+ */
+typedef void guac_rdpdr_set_information_request_handler(guac_rdp_common_svc* svc,
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        int length, wStream* input_stream);
+
 /**
  * Processes a query for FileBasicInformation. From the documentation, this is
  * "used to query a file for the times of creation, last access, last write,
  * and change, in addition to file attribute information."
  */
-void guac_rdpdr_fs_process_query_basic_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_basic_info;
 
 /**
  * Processes a query for FileStandardInformation. From the documentation, this
  * is "used to query for file information such as allocation size, end-of-file
  * position, and number of links."
  */
-void guac_rdpdr_fs_process_query_standard_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_standard_info;
 
 /**
  * Processes a query for FileAttributeTagInformation. From the documentation
  * this is "used to query for file attribute and reparse tag information."
  */
-void guac_rdpdr_fs_process_query_attribute_tag_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_attribute_tag_info;
 
 /**
  * Process a set operation for FileRenameInformation. From the documentation,
  * this operation is used to rename a file.
  */
-void guac_rdpdr_fs_process_set_rename_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length);
+guac_rdpdr_set_information_request_handler guac_rdpdr_fs_process_set_rename_info;
 
 /**
  * Process a set operation for FileAllocationInformation. From the
  * documentation, this operation is used to set a file's allocation size.
  */
-void guac_rdpdr_fs_process_set_allocation_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length);
+guac_rdpdr_set_information_request_handler guac_rdpdr_fs_process_set_allocation_info;
 
 /**
  * Process a set operation for FileDispositionInformation. From the
  * documentation, this operation is used to mark a file for deletion.
  */
-void guac_rdpdr_fs_process_set_disposition_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length);
+guac_rdpdr_set_information_request_handler guac_rdpdr_fs_process_set_disposition_info;
 
 /**
  * Process a set operation for FileEndOfFileInformation. From the
  * documentation, this operation is used "to set end-of-file information for
  * a file."
  */
-void guac_rdpdr_fs_process_set_end_of_file_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length);
+guac_rdpdr_set_information_request_handler guac_rdpdr_fs_process_set_end_of_file_info;
 
 /**
  * Process a set operation for FileBasicInformation. From the documentation,
  * this is "used to set file information such as the times of creation, last
  * access, last write, and change, in addition to file attributes."
  */
-void guac_rdpdr_fs_process_set_basic_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int length);
+guac_rdpdr_set_information_request_handler guac_rdpdr_fs_process_set_basic_info;
 
 #endif
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.c b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.c
index 77f4cce8..1ab9dd21 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.c
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.c
@@ -19,6 +19,8 @@
 
 #include "config.h"
 #include "channels/rdpdr/rdpdr-messages.h"
+#include "channels/rdpdr/rdpdr-fs-messages-vol-info.h"
+#include "channels/rdpdr/rdpdr-fs.h"
 #include "channels/rdpdr/rdpdr.h"
 #include "fs.h"
 
@@ -28,15 +30,14 @@
 #include <winpr/wtypes.h>
 
 void guac_rdpdr_fs_process_query_volume_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 21 + GUAC_FILESYSTEM_LABEL_LENGTH);
+            iorequest->completion_id, STATUS_SUCCESS, 21 + GUAC_FILESYSTEM_LABEL_LENGTH);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
     Stream_Write_UINT32(output_stream, 17 + GUAC_FILESYSTEM_LABEL_LENGTH);
     Stream_Write_UINT64(output_stream, 0); /* VolumeCreationTime */
@@ -51,18 +52,17 @@ void guac_rdpdr_fs_process_query_volume_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_size_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     guac_rdp_fs_info info = {0};
     guac_rdp_fs_get_info((guac_rdp_fs*) device->data, &info);
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 28);
+            iorequest->completion_id, STATUS_SUCCESS, 28);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
     Stream_Write_UINT32(output_stream, 24);
     Stream_Write_UINT64(output_stream, info.blocks_total);     /* TotalAllocationUnits */
@@ -75,15 +75,14 @@ void guac_rdpdr_fs_process_query_size_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_device_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 12);
+            iorequest->completion_id, STATUS_SUCCESS, 12);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
     Stream_Write_UINT32(output_stream, 8);
     Stream_Write_UINT32(output_stream, FILE_DEVICE_DISK); /* DeviceType */
@@ -94,17 +93,16 @@ void guac_rdpdr_fs_process_query_device_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_attribute_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     int name_len = guac_utf8_strlen(device->device_name);
     
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 16 + name_len);
+            iorequest->completion_id, STATUS_SUCCESS, 16 + name_len);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
     Stream_Write_UINT32(output_stream, 12 + name_len);
     Stream_Write_UINT32(output_stream,
@@ -120,18 +118,17 @@ void guac_rdpdr_fs_process_query_attribute_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_query_full_size_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     guac_rdp_fs_info info = {0};
     guac_rdp_fs_get_info((guac_rdp_fs*) device->data, &info);
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 36);
+            iorequest->completion_id, STATUS_SUCCESS, 36);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]", __func__,
+            iorequest->file_id);
 
     Stream_Write_UINT32(output_stream, 32);
     Stream_Write_UINT64(output_stream, info.blocks_total);     /* TotalAllocationUnits */
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.h b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.h
index 9f0d10aa..87c0745c 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages-vol-info.h
@@ -38,37 +38,27 @@
  * documentation, this is "used to query information for a volume on which a
  * file system is mounted."
  */
-void guac_rdpdr_fs_process_query_volume_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_volume_info;
 
 /**
  * Processes a query request for FileFsSizeInformation.
  */
-void guac_rdpdr_fs_process_query_size_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_size_info;
 
 /**
  * Processes a query request for FileFsAttributeInformation.
  */
-void guac_rdpdr_fs_process_query_attribute_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_attribute_info;
 
 /**
  * Processes a query request for FileFsFullSizeInformation.
  */
-void guac_rdpdr_fs_process_query_full_size_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_full_size_info;
 
 /**
  * Processes a query request for FileFsDeviceInformation.
  */
-void guac_rdpdr_fs_process_query_device_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_device_info;
 
 #endif
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.c b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.c
index c8113d1a..4fede57a 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.c
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.c
@@ -39,7 +39,8 @@
 #include <string.h>
 
 void guac_rdpdr_fs_process_create(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream;
     int file_id;
@@ -79,8 +80,8 @@ void guac_rdpdr_fs_process_create(guac_rdp_common_svc* svc,
         guac_client_log(svc->client, GUAC_LOG_ERROR,
                 "File open refused (%i): \"%s\"", file_id, path);
 
-        output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-                guac_rdp_fs_get_status(file_id), 5);
+        output_stream = guac_rdpdr_new_io_completion(device,
+                iorequest->completion_id, guac_rdp_fs_get_status(file_id), 5);
         Stream_Write_UINT32(output_stream, 0); /* fileId */
         Stream_Write_UINT8(output_stream,  0); /* information */
     }
@@ -90,8 +91,8 @@ void guac_rdpdr_fs_process_create(guac_rdp_common_svc* svc,
 
         guac_rdp_fs_file* file;
 
-        output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-                STATUS_SUCCESS, 5);
+        output_stream = guac_rdpdr_new_io_completion(device,
+                iorequest->completion_id, STATUS_SUCCESS, 5);
         Stream_Write_UINT32(output_stream, file_id);    /* fileId */
         Stream_Write_UINT8(output_stream,  0);          /* information */
 
@@ -113,8 +114,8 @@ void guac_rdpdr_fs_process_create(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_read(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     UINT32 length;
     UINT64 offset;
@@ -129,7 +130,7 @@ void guac_rdpdr_fs_process_read(guac_rdp_common_svc* svc,
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i] length=%i, offset=%" PRIu64,
-             __func__, file_id, length, (uint64_t) offset);
+             __func__, iorequest->file_id, length, (uint64_t) offset);
 
     /* Ensure buffer size does not exceed a safe maximum */
     if (length > GUAC_RDP_MAX_READ_BUFFER)
@@ -139,20 +140,20 @@ void guac_rdpdr_fs_process_read(guac_rdp_common_svc* svc,
     buffer = malloc(length);
 
     /* Attempt read */
-    bytes_read = guac_rdp_fs_read((guac_rdp_fs*) device->data, file_id, offset,
-            buffer, length);
+    bytes_read = guac_rdp_fs_read((guac_rdp_fs*) device->data,
+            iorequest->file_id, offset, buffer, length);
 
     /* If error, return invalid parameter */
     if (bytes_read < 0) {
-        output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-                guac_rdp_fs_get_status(bytes_read), 4);
+        output_stream = guac_rdpdr_new_io_completion(device,
+                iorequest->completion_id, guac_rdp_fs_get_status(bytes_read), 4);
         Stream_Write_UINT32(output_stream, 0); /* Length */
     }
 
     /* Otherwise, send bytes read */
     else {
-        output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-                STATUS_SUCCESS, 4+bytes_read);
+        output_stream = guac_rdpdr_new_io_completion(device,
+                iorequest->completion_id, STATUS_SUCCESS, 4+bytes_read);
         Stream_Write_UINT32(output_stream, bytes_read);  /* Length */
         Stream_Write(output_stream, buffer, bytes_read); /* ReadData */
     }
@@ -163,8 +164,8 @@ void guac_rdpdr_fs_process_read(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_write(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     UINT32 length;
     UINT64 offset;
@@ -179,24 +180,24 @@ void guac_rdpdr_fs_process_write(guac_rdp_common_svc* svc,
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i] length=%i, offset=%" PRIu64,
-             __func__, file_id, length, (uint64_t) offset);
+             __func__, iorequest->file_id, length, (uint64_t) offset);
 
     /* Attempt write */
-    bytes_written = guac_rdp_fs_write((guac_rdp_fs*) device->data, file_id,
-            offset, Stream_Pointer(input_stream), length);
+    bytes_written = guac_rdp_fs_write((guac_rdp_fs*) device->data,
+            iorequest->file_id, offset, Stream_Pointer(input_stream), length);
 
     /* If error, return invalid parameter */
     if (bytes_written < 0) {
-        output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-                guac_rdp_fs_get_status(bytes_written), 5);
+        output_stream = guac_rdpdr_new_io_completion(device,
+                iorequest->completion_id, guac_rdp_fs_get_status(bytes_written), 5);
         Stream_Write_UINT32(output_stream, 0); /* Length */
         Stream_Write_UINT8(output_stream, 0);  /* Padding */
     }
 
     /* Otherwise, send success */
     else {
-        output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-                STATUS_SUCCESS, 5);
+        output_stream = guac_rdpdr_new_io_completion(device,
+                iorequest->completion_id, STATUS_SUCCESS, 5);
         Stream_Write_UINT32(output_stream, bytes_written); /* Length */
         Stream_Write_UINT8(output_stream, 0);              /* Padding */
     }
@@ -206,18 +207,17 @@ void guac_rdpdr_fs_process_write(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_close(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream;
     guac_rdp_fs_file* file;
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i]",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i]",
+            __func__, iorequest->file_id);
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, iorequest->file_id);
     if (file == NULL)
         return;
 
@@ -225,14 +225,14 @@ void guac_rdpdr_fs_process_close(guac_rdp_common_svc* svc,
     if (file->bytes_written > 0 &&
             strncmp(file->absolute_path, "\\Download\\", 10) == 0) {
         guac_rdpdr_start_download(svc, device, file->absolute_path);
-        guac_rdp_fs_delete((guac_rdp_fs*) device->data, file_id);
+        guac_rdp_fs_delete((guac_rdp_fs*) device->data, iorequest->file_id);
     }
 
     /* Close file */
-    guac_rdp_fs_close((guac_rdp_fs*) device->data, file_id);
+    guac_rdp_fs_close((guac_rdp_fs*) device->data, iorequest->file_id);
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_SUCCESS, 4);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_SUCCESS, 4);
     Stream_Write(output_stream, "\0\0\0\0", 4); /* Padding */
 
     guac_rdp_common_svc_write(svc, output_stream);
@@ -240,8 +240,8 @@ void guac_rdpdr_fs_process_close(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_volume_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     int fs_information_class;
 
@@ -251,28 +251,23 @@ void guac_rdpdr_fs_process_volume_info(guac_rdp_common_svc* svc,
     switch (fs_information_class) {
 
         case FileFsVolumeInformation:
-            guac_rdpdr_fs_process_query_volume_info(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_query_volume_info(svc, device, iorequest, input_stream);
             break;
 
         case FileFsSizeInformation:
-            guac_rdpdr_fs_process_query_size_info(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_query_size_info(svc, device, iorequest, input_stream);
             break;
 
         case FileFsDeviceInformation:
-            guac_rdpdr_fs_process_query_device_info(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_query_device_info(svc, device, iorequest, input_stream);
             break;
 
         case FileFsAttributeInformation:
-            guac_rdpdr_fs_process_query_attribute_info(svc, device,
-                    input_stream, file_id, completion_id);
+            guac_rdpdr_fs_process_query_attribute_info(svc, device, iorequest, input_stream);
             break;
 
         case FileFsFullSizeInformation:
-            guac_rdpdr_fs_process_query_full_size_info(svc, device,
-                    input_stream, file_id, completion_id);
+            guac_rdpdr_fs_process_query_full_size_info(svc, device, iorequest, input_stream);
             break;
 
         default:
@@ -283,8 +278,8 @@ void guac_rdpdr_fs_process_volume_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_file_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     int fs_information_class;
 
@@ -294,18 +289,15 @@ void guac_rdpdr_fs_process_file_info(guac_rdp_common_svc* svc,
     switch (fs_information_class) {
 
         case FileBasicInformation:
-            guac_rdpdr_fs_process_query_basic_info(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_query_basic_info(svc, device, iorequest, input_stream);
             break;
 
         case FileStandardInformation:
-            guac_rdpdr_fs_process_query_standard_info(svc, device,
-                    input_stream, file_id, completion_id);
+            guac_rdpdr_fs_process_query_standard_info(svc, device, iorequest, input_stream);
             break;
 
         case FileAttributeTagInformation:
-            guac_rdpdr_fs_process_query_attribute_tag_info(svc, device,
-                    input_stream, file_id, completion_id);
+            guac_rdpdr_fs_process_query_attribute_tag_info(svc, device, iorequest, input_stream);
             break;
 
         default:
@@ -316,23 +308,23 @@ void guac_rdpdr_fs_process_file_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_set_volume_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_NOT_SUPPORTED, 0);
+            iorequest->completion_id, STATUS_NOT_SUPPORTED, 0);
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i] Set volume info not supported",
-            __func__, file_id);
+            __func__, iorequest->file_id);
 
     guac_rdp_common_svc_write(svc, output_stream);
 
 }
 
 void guac_rdpdr_fs_process_set_file_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     int fs_information_class;
     int length;
@@ -345,28 +337,23 @@ void guac_rdpdr_fs_process_set_file_info(guac_rdp_common_svc* svc,
     switch (fs_information_class) {
 
         case FileBasicInformation:
-            guac_rdpdr_fs_process_set_basic_info(svc, device, input_stream,
-                    file_id, completion_id, length);
+            guac_rdpdr_fs_process_set_basic_info(svc, device, iorequest, length, input_stream);
             break;
 
         case FileEndOfFileInformation:
-            guac_rdpdr_fs_process_set_end_of_file_info(svc, device,
-                    input_stream, file_id, completion_id, length);
+            guac_rdpdr_fs_process_set_end_of_file_info(svc, device, iorequest, length, input_stream);
             break;
 
         case FileDispositionInformation:
-            guac_rdpdr_fs_process_set_disposition_info(svc, device,
-                    input_stream, file_id, completion_id, length);
+            guac_rdpdr_fs_process_set_disposition_info(svc, device, iorequest, length, input_stream);
             break;
 
         case FileRenameInformation:
-            guac_rdpdr_fs_process_set_rename_info(svc, device, input_stream,
-                    file_id, completion_id, length);
+            guac_rdpdr_fs_process_set_rename_info(svc, device, iorequest, length, input_stream);
             break;
 
         case FileAllocationInformation:
-            guac_rdpdr_fs_process_set_allocation_info(svc, device,
-                    input_stream, file_id, completion_id, length);
+            guac_rdpdr_fs_process_set_allocation_info(svc, device, iorequest, length, input_stream);
             break;
 
         default:
@@ -378,15 +365,14 @@ void guac_rdpdr_fs_process_set_file_info(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_device_control(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_INVALID_PARAMETER, 4);
+            iorequest->completion_id, STATUS_INVALID_PARAMETER, 4);
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i] IGNORED",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i] IGNORED",
+            __func__, iorequest->file_id);
 
     /* No content for now */
     Stream_Write_UINT32(output_stream, 0);
@@ -396,18 +382,17 @@ void guac_rdpdr_fs_process_device_control(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_notify_change_directory(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i] Not implemented",
-            __func__, file_id);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i] Not "
+            "implemented", __func__, iorequest->file_id);
 
 }
 
 void guac_rdpdr_fs_process_query_directory(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream;
 
@@ -418,7 +403,7 @@ void guac_rdpdr_fs_process_query_directory(guac_rdp_common_svc* svc,
     const char* entry_name;
 
     /* Get file */
-    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, file_id);
+    file = guac_rdp_fs_get_file((guac_rdp_fs*) device->data, iorequest->file_id);
     if (file == NULL)
         return;
 
@@ -438,13 +423,13 @@ void guac_rdpdr_fs_process_query_directory(guac_rdp_common_svc* svc,
 
     }
 
-    guac_client_log(svc->client, GUAC_LOG_DEBUG,
-            "%s: [file_id=%i] initial_query=%i, dir_pattern=\"%s\"",
-             __func__, file_id, initial_query, file->dir_pattern);
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "%s: [file_id=%i] "
+            "initial_query=%i, dir_pattern=\"%s\"", __func__,
+            iorequest->file_id, initial_query, file->dir_pattern);
 
     /* Find first matching entry in directory */
     while ((entry_name = guac_rdp_fs_read_dir((guac_rdp_fs*) device->data,
-                    file_id)) != NULL) {
+                    iorequest->file_id)) != NULL) {
 
         /* Convert to absolute path */
         char entry_path[GUAC_RDP_FS_MAX_PATH];
@@ -468,24 +453,22 @@ void guac_rdpdr_fs_process_query_directory(guac_rdp_common_svc* svc,
 
                     case FileDirectoryInformation:
                         guac_rdpdr_fs_process_query_directory_info(svc, device,
-                                entry_name, entry_file_id, completion_id);
+                                iorequest, entry_name, entry_file_id);
                         break;
 
                     case FileFullDirectoryInformation:
                         guac_rdpdr_fs_process_query_full_directory_info(svc,
-                                device, entry_name, entry_file_id,
-                                completion_id);
+                                device, iorequest, entry_name, entry_file_id);
                         break;
 
                     case FileBothDirectoryInformation:
                         guac_rdpdr_fs_process_query_both_directory_info(svc,
-                                device, entry_name, entry_file_id,
-                                completion_id);
+                                device, iorequest, entry_name, entry_file_id);
                         break;
 
                     case FileNamesInformation:
                         guac_rdpdr_fs_process_query_names_info(svc, device,
-                                entry_name, entry_file_id, completion_id);
+                                iorequest, entry_name, entry_file_id);
                         break;
 
                     default:
@@ -505,8 +488,8 @@ void guac_rdpdr_fs_process_query_directory(guac_rdp_common_svc* svc,
      * Handle errors as a lack of files.
      */
 
-    output_stream = guac_rdpdr_new_io_completion(device, completion_id,
-            STATUS_NO_MORE_FILES, 5);
+    output_stream = guac_rdpdr_new_io_completion(device,
+            iorequest->completion_id, STATUS_NO_MORE_FILES, 5);
 
     Stream_Write_UINT32(output_stream, 0); /* Length */
     Stream_Write_UINT8(output_stream, 0);  /* Padding */
@@ -516,15 +499,15 @@ void guac_rdpdr_fs_process_query_directory(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_fs_process_lock_control(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_NOT_SUPPORTED, 5);
+            iorequest->completion_id, STATUS_NOT_SUPPORTED, 5);
 
     guac_client_log(svc->client, GUAC_LOG_DEBUG,
             "%s: [file_id=%i] Lock not supported",
-            __func__, file_id);
+            __func__, iorequest->file_id);
 
     Stream_Zero(output_stream, 5); /* Padding */
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.h b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.h
index dd5454cc..bfc8312b 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs-messages.h
@@ -37,37 +37,28 @@
  * Handles a Server Create Drive Request. Despite its name, this request opens
  * a file.
  */
-void guac_rdpdr_fs_process_create(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_create;
 
 /**
- * Handles a Server Close Drive Reqiest. This request closes an open file.
+ * Handles a Server Close Drive Request. This request closes an open file.
  */
-void guac_rdpdr_fs_process_close(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_close;
 
 /**
  * Handles a Server Drive Read Request. This request reads from a file.
  */
-void guac_rdpdr_fs_process_read(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_read;
 
 /**
  * Handles a Server Drive Write Request. This request writes to a file.
  */
-void guac_rdpdr_fs_process_write(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_write;
 
 /**
  * Handles a Server Drive Control Request. This request handles one of any
  * number of Windows FSCTL_* control functions.
  */
-void guac_rdpdr_fs_process_device_control(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_device_control;
 
 /**
  * Handles a Server Drive Query Volume Information Request. This request
@@ -75,60 +66,46 @@ void guac_rdpdr_fs_process_device_control(guac_rdp_common_svc* svc,
  * has several query types which have their own handlers defined in a
  * separate file.
  */
-void guac_rdpdr_fs_process_volume_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_volume_info;
 
 /**
  * Handles a Server Drive Set Volume Information Request. Currently, this
  * RDPDR implementation does not support setting of volume information.
  */
-void guac_rdpdr_fs_process_set_volume_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_set_volume_info;
 
 /**
  * Handles a Server Drive Query Information Request. This request queries
  * information about a specific file. This request has several query types
  * which have their own handlers defined in a separate file.
  */
-void guac_rdpdr_fs_process_file_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_file_info;
 
 /**
  * Handles a Server Drive Set Information Request. This request sets
  * information about a specific file. Currently, this RDPDR implementation does
  * not support setting of file information.
  */
-void guac_rdpdr_fs_process_set_file_info(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_set_file_info;
 
 /**
  * Handles a Server Drive Query Directory Request. This request queries
  * information about a specific directory. This request has several query types
  * which have their own handlers defined in a separate file.
  */
-void guac_rdpdr_fs_process_query_directory(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_query_directory;
 
 /**
  * Handles a Server Drive NotifyChange Directory Request. This request requests
  * directory change notification.
  */
-void guac_rdpdr_fs_process_notify_change_directory(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_notify_change_directory;
 
 /**
  * Handles a Server Drive Lock Control Request. This request locks or unlocks
  * portions of a file.
  */
-void guac_rdpdr_fs_process_lock_control(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id);
+guac_rdpdr_device_iorequest_handler guac_rdpdr_fs_process_lock_control;
 
 #endif
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs.c b/src/protocols/rdp/channels/rdpdr/rdpdr-fs.c
index 3ca862cf..87e7d9fc 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs.c
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs.c
@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "channels/rdpdr/rdpdr-fs-messages.h"
+#include "channels/rdpdr/rdpdr-fs.h"
 #include "channels/rdpdr/rdpdr-messages.h"
 #include "channels/rdpdr/rdpdr.h"
 #include "rdp.h"
@@ -30,96 +31,85 @@
 #include <guacamole/unicode.h>
 #include <winpr/stream.h>
 
-static void guac_rdpdr_device_fs_iorequest_handler(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int major_func, int minor_func) {
+void guac_rdpdr_device_fs_iorequest_handler(guac_rdp_common_svc* svc,
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
-    switch (major_func) {
+    switch (iorequest->major_func) {
 
         /* File open */
         case IRP_MJ_CREATE:
-            guac_rdpdr_fs_process_create(svc, device, input_stream,
-                    completion_id);
+            guac_rdpdr_fs_process_create(svc, device, iorequest, input_stream);
             break;
 
         /* File close */
         case IRP_MJ_CLOSE:
-            guac_rdpdr_fs_process_close(svc, device, input_stream, file_id,
-                    completion_id);
+            guac_rdpdr_fs_process_close(svc, device, iorequest, input_stream);
             break;
 
         /* File read */
         case IRP_MJ_READ:
-            guac_rdpdr_fs_process_read(svc, device, input_stream, file_id,
-                    completion_id);
+            guac_rdpdr_fs_process_read(svc, device, iorequest, input_stream);
             break;
 
         /* File write */
         case IRP_MJ_WRITE:
-            guac_rdpdr_fs_process_write(svc, device, input_stream, file_id,
-                    completion_id);
+            guac_rdpdr_fs_process_write(svc, device, iorequest, input_stream);
             break;
 
         /* Device control request (Windows FSCTL_ control codes) */
         case IRP_MJ_DEVICE_CONTROL:
-            guac_rdpdr_fs_process_device_control(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_device_control(svc, device, iorequest, input_stream);
             break;
 
         /* Query volume (drive) information */
         case IRP_MJ_QUERY_VOLUME_INFORMATION:
-            guac_rdpdr_fs_process_volume_info(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_volume_info(svc, device, iorequest, input_stream);
             break;
 
         /* Set volume (drive) information */
         case IRP_MJ_SET_VOLUME_INFORMATION:
-            guac_rdpdr_fs_process_set_volume_info(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_set_volume_info(svc, device, iorequest, input_stream);
             break;
 
         /* Query file information */
         case IRP_MJ_QUERY_INFORMATION:
-            guac_rdpdr_fs_process_file_info(svc, device, input_stream, file_id,
-                    completion_id);
+            guac_rdpdr_fs_process_file_info(svc, device, iorequest, input_stream);
             break;
 
         /* Set file information */
         case IRP_MJ_SET_INFORMATION:
-            guac_rdpdr_fs_process_set_file_info(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_set_file_info(svc, device, iorequest, input_stream);
             break;
 
         case IRP_MJ_DIRECTORY_CONTROL:
 
             /* Enumerate directory contents */
-            if (minor_func == IRP_MN_QUERY_DIRECTORY)
-                guac_rdpdr_fs_process_query_directory(svc, device,
-                        input_stream, file_id, completion_id);
+            if (iorequest->minor_func == IRP_MN_QUERY_DIRECTORY)
+                guac_rdpdr_fs_process_query_directory(svc, device, iorequest,
+                        input_stream);
 
             /* Request notification of changes to directory */
-            else if (minor_func == IRP_MN_NOTIFY_CHANGE_DIRECTORY)
+            else if (iorequest->minor_func == IRP_MN_NOTIFY_CHANGE_DIRECTORY)
                 guac_rdpdr_fs_process_notify_change_directory(svc, device,
-                        input_stream,
-                        file_id, completion_id);
+                        iorequest, input_stream);
 
             break;
 
         /* Lock/unlock portions of a file */
         case IRP_MJ_LOCK_CONTROL:
-            guac_rdpdr_fs_process_lock_control(svc, device, input_stream,
-                    file_id, completion_id);
+            guac_rdpdr_fs_process_lock_control(svc, device, iorequest, input_stream);
             break;
 
         default:
             guac_client_log(svc->client, GUAC_LOG_ERROR,
                     "Unknown filesystem I/O request function: 0x%x/0x%x",
-                    major_func, minor_func);
+                    iorequest->major_func, iorequest->minor_func);
     }
 
 }
 
-static void guac_rdpdr_device_fs_free_handler(guac_rdp_common_svc* svc,
+void guac_rdpdr_device_fs_free_handler(guac_rdp_common_svc* svc,
         guac_rdpdr_device* device) {
 
     Stream_Free(device->device_announce, 1);
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-fs.h b/src/protocols/rdp/channels/rdpdr/rdpdr-fs.h
index ab8a13db..6f6e5d1d 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-fs.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-fs.h
@@ -36,6 +36,16 @@
 
 #include <guacamole/pool.h>
 
+/**
+ * The UTF-16 string that should be sent as the label of the filesystem.
+ */
+#define GUAC_FILESYSTEM_LABEL "G\0U\0A\0C\0F\0I\0L\0E\0"
+
+/**
+ * The size of GUAC_FILESYSTEM_LABEL in bytes.
+ */
+#define GUAC_FILESYSTEM_LABEL_LENGTH 16
+
 /**
  * Registers a new filesystem device within the RDPDR plugin. This must be done
  * before RDPDR connection finishes.
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-messages.c b/src/protocols/rdp/channels/rdpdr/rdpdr-messages.c
index b9b67383..21bb3162 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-messages.c
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-messages.c
@@ -31,6 +31,28 @@
 #include <stdlib.h>
 #include <string.h>
 
+/**
+ * Sends a Client Announce Reply message. The Client Announce Reply message is
+ * required to be sent in response to the Server Announce Request message. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/d6fe6d1b-c145-4a6f-99aa-4fe3cdcea398
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ *
+ * @param major
+ *     The major version of the RDPDR protocol in use. This value must always
+ *     be 1.
+ *
+ * @param minor
+ *     The minor version of the RDPDR protocol in use. This value must be
+ *     either 2, 5, 10, 12, or 13.
+ *
+ * @param client_id
+ *     The client ID received in the Server Announce Request, or a randomly
+ *     generated ID.
+ */
 static void guac_rdpdr_send_client_announce_reply(guac_rdp_common_svc* svc,
         unsigned int major, unsigned int minor, unsigned int client_id) {
 
@@ -49,6 +71,19 @@ static void guac_rdpdr_send_client_announce_reply(guac_rdp_common_svc* svc,
 
 }
 
+/**
+ * Sends a Client Name Request message. The Client Name Request message is used
+ * by the client to announce its own name. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/902497f1-3b1c-4aee-95f8-1668f9b7b7d2
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ *
+ * @param name
+ *     The name that should be used for the client.
+ */
 static void guac_rdpdr_send_client_name_request(guac_rdp_common_svc* svc,
         const char* name) {
 
@@ -69,6 +104,18 @@ static void guac_rdpdr_send_client_name_request(guac_rdp_common_svc* svc,
 
 }
 
+/**
+ * Sends a Client Core Capability Response message. The Client Core Capability
+ * Response message is used to announce the client's capabilities, in response
+ * to receiving the server's capabilities via a Server Core Capability Request.
+ * See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/f513bf87-cca0-488a-ac5c-18cf18f4a7e1
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ */
 static void guac_rdpdr_send_client_capability(guac_rdp_common_svc* svc) {
 
     wStream* output_stream = Stream_New(NULL, 256);
@@ -117,6 +164,17 @@ static void guac_rdpdr_send_client_capability(guac_rdp_common_svc* svc) {
 
 }
 
+/**
+ * Sends a Client Device List Announce Request message. The Client Device List
+ * Announce Request message is used by the client to enumerate all devices
+ * which should be made available within the RDP session via RDPDR. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/10ef9ada-cba2-4384-ab60-7b6290ed4a9a
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ */
 static void guac_rdpdr_send_client_device_list_announce_request(guac_rdp_common_svc* svc) {
 
     guac_rdpdr* rdpdr = (guac_rdpdr*) svc->data;
@@ -220,28 +278,27 @@ void guac_rdpdr_process_device_iorequest(guac_rdp_common_svc* svc,
         wStream* input_stream) {
 
     guac_rdpdr* rdpdr = (guac_rdpdr*) svc->data;
-
-    int device_id, file_id, completion_id, major_func, minor_func;
+    guac_rdpdr_iorequest iorequest;
 
     /* Read header */
-    Stream_Read_UINT32(input_stream, device_id);
-    Stream_Read_UINT32(input_stream, file_id);
-    Stream_Read_UINT32(input_stream, completion_id);
-    Stream_Read_UINT32(input_stream, major_func);
-    Stream_Read_UINT32(input_stream, minor_func);
+    Stream_Read_UINT32(input_stream, iorequest.device_id);
+    Stream_Read_UINT32(input_stream, iorequest.file_id);
+    Stream_Read_UINT32(input_stream, iorequest.completion_id);
+    Stream_Read_UINT32(input_stream, iorequest.major_func);
+    Stream_Read_UINT32(input_stream, iorequest.minor_func);
 
     /* If printer, run printer handlers */
-    if (device_id >= 0 && device_id < rdpdr->devices_registered) {
+    if (iorequest.device_id >= 0 && iorequest.device_id < rdpdr->devices_registered) {
 
         /* Call handler on device */
-        guac_rdpdr_device* device = &(rdpdr->devices[device_id]);
-        device->iorequest_handler(svc, device, input_stream,
-                file_id, completion_id, major_func, minor_func);
+        guac_rdpdr_device* device = &(rdpdr->devices[iorequest.device_id]);
+        device->iorequest_handler(svc, device, &iorequest, input_stream);
 
     }
 
     else
-        guac_client_log(svc->client, GUAC_LOG_ERROR, "Unknown device ID: 0x%08x", device_id);
+        guac_client_log(svc->client, GUAC_LOG_ERROR, "Unknown device ID: "
+                "0x%08x", iorequest.device_id);
 
 }
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-messages.h b/src/protocols/rdp/channels/rdpdr/rdpdr-messages.h
index d1352d72..27684cf2 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-messages.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-messages.h
@@ -35,29 +35,102 @@
 #define GUAC_OS_TYPE (*((uint32_t*) "GUAC"))
 
 /**
- * Name of the printer driver that should be used on the server.
+ * Handler which processes a message specific to the RDPDR channel.
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ *
+ * @param input_stream
+ *     A wStream containing the entire received message.
  */
-#define GUAC_PRINTER_DRIVER        "M\0S\0 \0P\0u\0b\0l\0i\0s\0h\0e\0r\0 \0I\0m\0a\0g\0e\0s\0e\0t\0t\0e\0r\0\0\0"
-#define GUAC_PRINTER_DRIVER_LENGTH 50
+typedef void guac_rdpdr_message_handler(guac_rdp_common_svc* svc,
+        wStream* input_stream);
 
 /**
- * Label of the filesystem.
+ * Handler which processes a received Server Announce Request message. The
+ * Server Announce Request message begins the RDPDR exchange and provides a
+ * client ID which the RDPDR client may use. The client may also supply its
+ * own, randomly-generated ID, and is required to do so for older versions of
+ * RDPDR. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/046047aa-62d8-49f9-bf16-7fe41880aaf4
  */
-#define GUAC_FILESYSTEM_LABEL          "G\0U\0A\0C\0F\0I\0L\0E\0"
-#define GUAC_FILESYSTEM_LABEL_LENGTH   16
+guac_rdpdr_message_handler guac_rdpdr_process_server_announce;
 
-/*
- * Message handlers.
+/**
+ * Handler which processes a received Server Client ID Confirm message. The
+ * Server Client ID Confirm message is sent by the server to confirm the client
+ * ID requested by the client (in its response to the Server Announce Request)
+ * has been accepted. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/bbbb9666-6994-4cf6-8e65-0d46eb319c6e
  */
+guac_rdpdr_message_handler guac_rdpdr_process_clientid_confirm;
 
-void guac_rdpdr_process_server_announce(guac_rdp_common_svc* svc, wStream* input_stream);
-void guac_rdpdr_process_clientid_confirm(guac_rdp_common_svc* svc, wStream* input_stream);
-void guac_rdpdr_process_device_reply(guac_rdp_common_svc* svc, wStream* input_stream);
-void guac_rdpdr_process_device_iorequest(guac_rdp_common_svc* svc, wStream* input_stream);
-void guac_rdpdr_process_server_capability(guac_rdp_common_svc* svc, wStream* input_stream);
-void guac_rdpdr_process_user_loggedon(guac_rdp_common_svc* svc, wStream* input_stream);
-void guac_rdpdr_process_prn_cache_data(guac_rdp_common_svc* svc, wStream* input_stream);
-void guac_rdpdr_process_prn_using_xps(guac_rdp_common_svc* svc, wStream* input_stream);
+/**
+ * Handler which processes a received Server Device Announce Response message.
+ * The Server Device Announce Response message is sent in response to a Client
+ * Device List Announce message to communicate the success/failure status of
+ * device creation. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/a4c0b619-6e87-4721-bdc4-5d2db7f485f3
+ */
+guac_rdpdr_message_handler guac_rdpdr_process_device_reply;
+
+/**
+ * Handler which processes a received Device I/O Request message. The Device
+ * I/O Request message makes up the majority of traffic once RDPDR is
+ * established. Each I/O request consists of a device-specific major/minor
+ * function number pair, as well as several parameters. Device-specific
+ * handling of I/O requests within Guacamole is delegated to device- and
+ * function-specific implementations of yet another function type:
+ * guac_rdpdr_device_iorequest_handler.
+ *
+ * See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/a087ffa8-d0d5-4874-ac7b-0494f63e2d5d
+ */
+guac_rdpdr_message_handler guac_rdpdr_process_device_iorequest;
+
+/**
+ * Handler which processes a received Server Core Capability Request message.
+ * The Server Core Capability Request message is sent by the server to
+ * communicate its capabilities and to request that the client communicate the
+ * same. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/702789c3-b924-4bc2-9280-3221bc7d6797
+ */
+guac_rdpdr_message_handler guac_rdpdr_process_server_capability;
+
+/**
+ * Handler which processes a received Server User Logged On message. The Server
+ * User Logged On message is sent by the server to notify that the user has
+ * logged on to the session. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/dfc0e8ed-a242-4d00-bb88-e779e08f2f61
+ */
+guac_rdpdr_message_handler guac_rdpdr_process_user_loggedon;
+
+/**
+ * Handler which processes any one of several RDPDR messages specific to cached
+ * printer configuration data, each of these messages having the same
+ * PAKID_PRN_CACHE_DATA packet ID. The Guacamole RDPDR implementation ignores
+ * all PAKID_PRN_CACHE_DATA messages. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpepc/7fccae60-f077-433b-9dee-9bad4238bf40
+ */
+guac_rdpdr_message_handler guac_rdpdr_process_prn_cache_data;
+
+/**
+ * Handler which processes a received Server Printer Set XPS Mode message. The
+ * Server Printer Set XPS Mode message is specific to printers and requests
+ * that the client printer be set to XPS mode. The Guacamole RDPDR
+ * implementation ignores any request to set the printer to XPS mode. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpepc/f1789a66-bcd0-4df3-bfc2-6e7330d63145
+ */
+guac_rdpdr_message_handler guac_rdpdr_process_prn_using_xps;
 
 #endif
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-printer.c b/src/protocols/rdp/channels/rdpdr/rdpdr-printer.c
index c3359631..e435d32b 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-printer.c
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-printer.c
@@ -43,7 +43,8 @@
 #include <unistd.h>
 
 void guac_rdpdr_process_print_job_create(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     guac_client* client = svc->client;
     guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
@@ -57,7 +58,7 @@ void guac_rdpdr_process_print_job_create(guac_rdp_common_svc* svc,
 
     /* Respond with success */
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 4);
+            iorequest->completion_id, STATUS_SUCCESS, 4);
 
     Stream_Write_UINT32(output_stream, 0); /* fileId */
     guac_rdp_common_svc_write(svc, output_stream);
@@ -65,7 +66,8 @@ void guac_rdpdr_process_print_job_create(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_process_print_job_write(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     guac_client* client = svc->client;
     guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
@@ -94,7 +96,7 @@ void guac_rdpdr_process_print_job_write(guac_rdp_common_svc* svc,
     }
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, status, 5);
+            iorequest->completion_id, status, 5);
 
     Stream_Write_UINT32(output_stream, length);
     Stream_Write_UINT8(output_stream, 0); /* Padding */
@@ -104,7 +106,8 @@ void guac_rdpdr_process_print_job_write(guac_rdp_common_svc* svc,
 }
 
 void guac_rdpdr_process_print_job_close(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int completion_id) {
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
     guac_client* client = svc->client;
     guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
@@ -117,7 +120,7 @@ void guac_rdpdr_process_print_job_close(guac_rdp_common_svc* svc,
     }
 
     wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 4);
+            iorequest->completion_id, STATUS_SUCCESS, 4);
 
     Stream_Write_UINT32(output_stream, 0); /* Padding */
     guac_rdp_common_svc_write(svc, output_stream);
@@ -127,41 +130,38 @@ void guac_rdpdr_process_print_job_close(guac_rdp_common_svc* svc,
 
 }
 
-static void guac_rdpdr_device_printer_iorequest_handler(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int major_func, int minor_func) {
+void guac_rdpdr_device_printer_iorequest_handler(guac_rdp_common_svc* svc,
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream) {
 
-    switch (major_func) {
+    switch (iorequest->major_func) {
 
         /* Print job create */
         case IRP_MJ_CREATE:
-            guac_rdpdr_process_print_job_create(svc, device, input_stream,
-                    completion_id);
+            guac_rdpdr_process_print_job_create(svc, device, iorequest, input_stream);
             break;
 
         /* Printer job write */
         case IRP_MJ_WRITE:
-            guac_rdpdr_process_print_job_write(svc, device, input_stream,
-                    completion_id);
+            guac_rdpdr_process_print_job_write(svc, device, iorequest, input_stream);
             break;
 
         /* Printer job close */
         case IRP_MJ_CLOSE:
-            guac_rdpdr_process_print_job_close(svc, device, input_stream,
-                    completion_id);
+            guac_rdpdr_process_print_job_close(svc, device, iorequest, input_stream);
             break;
 
         /* Log unknown */
         default:
-            guac_client_log(svc->client, GUAC_LOG_ERROR,
-                    "Unknown printer I/O request function: 0x%x/0x%x",
-                    major_func, minor_func);
+            guac_client_log(svc->client, GUAC_LOG_ERROR, "Unknown printer "
+                    "I/O request function: 0x%x/0x%x", iorequest->major_func,
+                    iorequest->minor_func);
 
     }
 
 }
 
-static void guac_rdpdr_device_printer_free_handler(guac_rdp_common_svc* svc,
+void guac_rdpdr_device_printer_free_handler(guac_rdp_common_svc* svc,
         guac_rdpdr_device* device) {
 
     Stream_Free(device->device_announce, 1);
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr-printer.h b/src/protocols/rdp/channels/rdpdr/rdpdr-printer.h
index 0addc6fb..106d6be3 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr-printer.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr-printer.h
@@ -25,6 +25,16 @@
 
 #include <winpr/stream.h>
 
+/**
+ * Name of the printer driver that should be used on the server.
+ */
+#define GUAC_PRINTER_DRIVER "M\0S\0 \0P\0u\0b\0l\0i\0s\0h\0e\0r\0 \0I\0m\0a\0g\0e\0s\0e\0t\0t\0e\0r\0\0\0"
+
+/**
+ * The size of GUAC_PRINTER_DRIVER in bytes.
+ */
+#define GUAC_PRINTER_DRIVER_LENGTH 50
+
 /**
  * Registers a new printer device within the RDPDR plugin. This must be done
  * before RDPDR connection finishes.
@@ -38,5 +48,34 @@
  */
 void guac_rdpdr_register_printer(guac_rdp_common_svc* svc, char* printer_name);
 
+/**
+ * I/O request handler which processes a print job creation request.
+ */
+guac_rdpdr_device_iorequest_handler guac_rdpdr_process_print_job_create;
+
+/**
+ * I/O request handler which processes a request to write data to an existing
+ * print job.
+ */
+guac_rdpdr_device_iorequest_handler guac_rdpdr_process_print_job_write;
+
+/**
+ * I/O request handler which processes a request to close an existing print
+ * job.
+ */
+guac_rdpdr_device_iorequest_handler guac_rdpdr_process_print_job_close;
+
+/**
+ * Handler for RDPDR Device I/O Requests which processes received messages on
+ * behalf of a printer device, in this case a simulated printer which produces
+ * PDF output.
+ */
+guac_rdpdr_device_iorequest_handler guac_rdpdr_device_printer_iorequest_handler;
+
+/**
+ * Free handler which frees all data specific to the simulated printer device.
+ */
+guac_rdpdr_device_free_handler guac_rdpdr_device_printer_free_handler;
+
 #endif
 
diff --git a/src/protocols/rdp/channels/rdpdr/rdpdr.h b/src/protocols/rdp/channels/rdpdr/rdpdr.h
index f75df0f0..19f178d0 100644
--- a/src/protocols/rdp/channels/rdpdr/rdpdr.h
+++ b/src/protocols/rdp/channels/rdpdr/rdpdr.h
@@ -37,21 +37,79 @@
 typedef struct guac_rdpdr_device guac_rdpdr_device;
 
 /**
- * Handler for client device list announce. Each implementing device must write
- * its announcement header and data to the given output stream.
+ * The contents of the header common to all RDPDR Device I/O Requests. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/a087ffa8-d0d5-4874-ac7b-0494f63e2d5d
  */
-typedef void guac_rdpdr_device_announce_handler(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* output_stream, int device_id);
+typedef struct guac_rdpdr_iorequest {
+
+    /**
+     * The unique ID assigned to the device receiving this I/O request.
+     */
+    int device_id;
+
+    /**
+     * The unique ID which identifies the relevant file, as returned when the
+     * file was opened. This field may not be relevant to all requests.
+     */
+    int file_id;
+
+    /**
+     * The unique ID that should be used to refer to this I/O request in future
+     * responses.
+     */
+    int completion_id;
+
+    /**
+     * Integer ID which identifies the function being requested, such as
+     * IRP_MJ_CREATE (open a file within a shared drive) or IRP_MJ_WRITE (write
+     * data to an open file).
+     */
+    int major_func;
+
+    /**
+     * Integer ID which identifies a variant of the function denoted by
+     * major_func. This value is only valid for IRP_MJ_DIRECTORY_CONTROL.
+     */
+    int minor_func;
+
+} guac_rdpdr_iorequest;
 
 /**
- * Handler for device I/O requests.
+ * Handler for Device I/O Requests. RDPDR devices must provide an
+ * implementation of this function to be able to handle inbound I/O requests.
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ *
+ * @param device
+ *     The guac_rdpdr_device of the relevant device, as dictated by the
+ *     deviceId field of common RDPDR header within the received PDU. Within
+ *     the guac_rdpdr_iorequest structure, the deviceId field is stored within
+ *     device_id.
+ *
+ * @param iorequest
+ *     The contents of the common RDPDR Device I/O Request header shared by all
+ *     RDPDR devices.
+ *
+ * @param input_stream
+ *     The remaining data within the received PDU, following the common RDPDR
+ *     Device I/O Request header.
  */
 typedef void guac_rdpdr_device_iorequest_handler(guac_rdp_common_svc* svc,
-        guac_rdpdr_device* device, wStream* input_stream, int file_id,
-        int completion_id, int major_func, int minor_func);
+        guac_rdpdr_device* device, guac_rdpdr_iorequest* iorequest,
+        wStream* input_stream);
 
 /**
  * Handler for cleaning up the dynamically-allocated portions of a device.
+ *
+ * @param svc
+ *     The guac_rdp_common_svc representing the static virtual channel being
+ *     used for RDPDR.
+ *
+ * @param device
+ *     The guac_rdpdr_device of the device being freed.
  */
 typedef void guac_rdpdr_device_free_handler(guac_rdp_common_svc* svc,
         guac_rdpdr_device* device);
@@ -126,7 +184,30 @@ typedef struct guac_rdpdr {
 
 /**
  * Creates a new stream which contains the common DR_DEVICE_IOCOMPLETION header
- * used for virtually all responses.
+ * used for virtually all responses. Depending on the specific I/O completion
+ * being sent, additional space may be reserved within the resulting stream for
+ * additional fields. See:
+ *
+ * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpefs/10ef9ada-cba2-4384-ab60-7b6290ed4a9a
+ *
+ * @param device
+ *     The device that completed the operation requested by a prior I/O
+ *     request.
+ *
+ * @param completion_id
+ *     The completion ID of the I/O request that requested the operation.
+ *
+ * @param status
+ *     An NTSTATUS code describing the success/failure of the operation that
+ *     was completed.
+ *
+ * @param size
+ *     The number of additional bytes to reserve at the end of the resulting
+ *     stream for additional fields to be appended.
+ *
+ * @return
+ *     A new wStream containing an I/O completion header, followed by the
+ *     requested additional free space.
  */
 wStream* guac_rdpdr_new_io_completion(guac_rdpdr_device* device,
         int completion_id, int status, int size);