From 296836f65d04c966bc4dd9819e9597f0361dc141 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mike.jumper@guac-dev.org>
Date: Tue, 5 Nov 2013 00:48:55 -0800
Subject: [PATCH] Implement file truncation.

---
 .../guac_rdpdr/rdpdr_fs_messages_file_info.c  | 42 +++++++++++++------
 src/protocols/rdp/rdp_fs.c                    | 20 +++++++++
 src/protocols/rdp/rdp_fs.h                    |  8 +++-
 3 files changed, 57 insertions(+), 13 deletions(-)

diff --git a/src/protocols/rdp/guac_rdpdr/rdpdr_fs_messages_file_info.c b/src/protocols/rdp/guac_rdpdr/rdpdr_fs_messages_file_info.c
index dbb10427..fa2e057a 100644
--- a/src/protocols/rdp/guac_rdpdr/rdpdr_fs_messages_file_info.c
+++ b/src/protocols/rdp/guac_rdpdr/rdpdr_fs_messages_file_info.c
@@ -177,15 +177,24 @@ void guac_rdpdr_fs_process_set_rename_info(guac_rdpdr_device* device,
 void guac_rdpdr_fs_process_set_allocation_info(guac_rdpdr_device* device,
         wStream* input_stream, int file_id, int completion_id, int length) {
 
-    wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 4);
+    int result;
+    UINT64 size;
+    wStream* output_stream;
+
+    /* Read new size */
+    Stream_Read_UINT64(input_stream, size); /* AllocationSize */
+
+    /* Truncate file */
+    result = guac_rdp_fs_truncate((guac_rdp_fs*) device->data, file_id, size);
+    if (result < 0)
+        output_stream = guac_rdpdr_new_io_completion(device,
+                completion_id, guac_rdp_fs_get_status(result), 4);
+    else
+        output_stream = guac_rdpdr_new_io_completion(device,
+                completion_id, STATUS_SUCCESS, 4);
 
-    /* Currently do nothing, just respond */
     Stream_Write_UINT32(output_stream, length);
-
     svc_plugin_send((rdpSvcPlugin*) device->rdpdr, output_stream);
-    GUAC_RDP_DEBUG(2, "Sent STATUS_SUCCESS for completion_id=%i",
-            completion_id);
 
 }
 
@@ -214,15 +223,24 @@ void guac_rdpdr_fs_process_set_disposition_info(guac_rdpdr_device* device,
 void guac_rdpdr_fs_process_set_end_of_file_info(guac_rdpdr_device* device,
         wStream* input_stream, int file_id, int completion_id, int length) {
 
-    wStream* output_stream = guac_rdpdr_new_io_completion(device,
-            completion_id, STATUS_SUCCESS, 4);
+    int result;
+    UINT64 size;
+    wStream* output_stream;
+
+    /* Read new size */
+    Stream_Read_UINT64(input_stream, size); /* AllocationSize */
+
+    /* Truncate file */
+    result = guac_rdp_fs_truncate((guac_rdp_fs*) device->data, file_id, size);
+    if (result < 0)
+        output_stream = guac_rdpdr_new_io_completion(device,
+                completion_id, guac_rdp_fs_get_status(result), 4);
+    else
+        output_stream = guac_rdpdr_new_io_completion(device,
+                completion_id, STATUS_SUCCESS, 4);
 
-    /* Currently do nothing, just respond */
     Stream_Write_UINT32(output_stream, length);
-
     svc_plugin_send((rdpSvcPlugin*) device->rdpdr, output_stream);
-    GUAC_RDP_DEBUG(2, "Sent STATUS_SUCCESS for completion_id=%i",
-            completion_id);
 
 }
 
diff --git a/src/protocols/rdp/rdp_fs.c b/src/protocols/rdp/rdp_fs.c
index 9c604c8c..48e1892c 100644
--- a/src/protocols/rdp/rdp_fs.c
+++ b/src/protocols/rdp/rdp_fs.c
@@ -429,6 +429,26 @@ int guac_rdp_fs_delete(guac_rdp_fs* fs, int file_id) {
 
 }
 
+int guac_rdp_fs_truncate(guac_rdp_fs* fs, int file_id, int length) {
+
+    /* Get file */
+    guac_rdp_fs_file* file = guac_rdp_fs_get_file(fs, file_id);
+    if (file == NULL) {
+        GUAC_RDP_DEBUG(1, "Delete of bad file_id: %i", file_id);
+        return GUAC_RDP_FS_EINVAL;
+    }
+
+    /* Attempt truncate */
+    if (ftruncate(file->fd, length)) {
+        GUAC_RDP_DEBUG(1, "ftruncate() to %i bytes failed: \"%s\"",
+                length, file->real_path);
+        return guac_rdp_fs_get_errorcode(errno);
+    }
+
+    return 0;
+
+}
+
 void guac_rdp_fs_close(guac_rdp_fs* fs, int file_id) {
 
     guac_rdp_fs_file* file = guac_rdp_fs_get_file(fs, file_id);
diff --git a/src/protocols/rdp/rdp_fs.h b/src/protocols/rdp/rdp_fs.h
index c9990b0e..96490781 100644
--- a/src/protocols/rdp/rdp_fs.h
+++ b/src/protocols/rdp/rdp_fs.h
@@ -342,10 +342,16 @@ int guac_rdp_fs_rename(guac_rdp_fs* fs, int file_id,
         const char* new_path);
 
 /**
- * Deletes the gile with the given ID.
+ * Deletes the file with the given ID.
  */
 int guac_rdp_fs_delete(guac_rdp_fs* fs, int file_id);
 
+/**
+ * Truncates the file with the given ID to the given length (in bytes), which
+ * may be larger.
+ */
+int guac_rdp_fs_truncate(guac_rdp_fs* fs, int file_id, int length);
+
 /**
  * Frees the given file ID, allowing future open operations to reuse it.
  */