Add path normalization.

src/protocols/rdp/guac_rdpdr/rdpdr_fs.c

@@ -61,11 +61,12 @@
 #include <freerdp/utils/svc_plugin.h>
 
 /**
- * Translates an absolute Windows path to an absolute path which is within the "drive path"
+ * Translates an absolute Windows virtual_path to an absolute virtual_path
- * specified in the connection settings.
+ * which is within the "drive virtual_path" specified in the connection
+ * settings.
  */
-static char* __guac_rdpdr_fs_translate_path(guac_rdpdr_device* device,
+static void __guac_rdpdr_fs_translate_path(guac_rdpdr_device* device,
-        const char* path, char* path_buffer) {
+        const char* virtual_path, char* real_path) {
 
     /* Get drive path */
     rdp_guac_client_data* client_data = (rdp_guac_client_data*) device->rdpdr->client->data;
@@ -82,7 +83,7 @@ static char* __guac_rdpdr_fs_translate_path(guac_rdpdr_device* device,
             break;
 
         /* Copy character */
-        *(path_buffer++) = c;
+        *(real_path++) = c;
 
     }
 
@@ -90,29 +91,21 @@ static char* __guac_rdpdr_fs_translate_path(guac_rdpdr_device* device,
     for (; i<GUAC_RDPDR_FS_MAX_PATH-1; i++) {
 
         /* Stop at end of string */
-        char c = *path;
+        char c = *(virtual_path++);
         if (c == 0)
             break;
 
-        /* Disallow ".." */
-        if (c == '.' && *(path-1) == '.')
-            return NULL;
-
         /* Translate backslashes to forward slashes */
         if (c == '\\')
             c = '/';
 
         /* Store in real path buffer */
-        *(path_buffer++)= c;
+        *(real_path++)= c;
-
-        /* Next path character */
-        path++;
 
     }
 
     /* Null terminator */
-    *(path_buffer++)= 0;
+    *real_path = 0;
-    return path_buffer;
 
 }
 
@@ -120,7 +113,8 @@ int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path,
         int access, int create_disposition) {
 
     guac_rdpdr_fs_data* data = (guac_rdpdr_fs_data*) device->data;
-    char path_buffer[GUAC_RDPDR_FS_MAX_PATH];
+    char real_path[GUAC_RDPDR_FS_MAX_PATH];
+    char normalized_path[GUAC_RDPDR_FS_MAX_PATH];
 
     struct stat file_stat;
     int fd;
@@ -192,15 +186,19 @@ int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path,
 
     }
 
-    /* If path invalid, return no such file */
+    /* Normalize path, return no-such-file if invalid  */
-    if (__guac_rdpdr_fs_translate_path(device, path, path_buffer) == NULL)
+    if (guac_rdpdr_fs_normalize_path(path, normalized_path))
         return GUAC_RDPDR_FS_ENOENT;
 
-    guac_client_log_info(device->rdpdr->client, "Path \"%s\" translated to \"%s\"",
+    /* Translate normalized path to real path */
-            path, path_buffer);
+    __guac_rdpdr_fs_translate_path(device, normalized_path, real_path);
+
+    guac_client_log_info(device->rdpdr->client,
+            "Path virtual=\"%s\" -> normalized=\"%s\", real=\"%s\"",
+            path, normalized_path, real_path);
 
     /* Open file */
-    fd = open(path_buffer, flags, mode);
+    fd = open(real_path, flags, mode);
     if (fd == -1)
         return GUAC_RDPDR_FS_ENOENT;
 
@@ -209,6 +207,7 @@ int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path,
     file = &(data->files[file_id]);
     file->fd  = fd;
     file->dir = NULL;
+    file->absolute_path = strdup(path);
 
     /* Attempt to pull file information */
     if (fstat(fd, &file_stat) == 0) {
@@ -231,7 +230,7 @@ int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path,
     else {
 
         guac_client_log_info(device->rdpdr->client, "Unable to read information for \"%s\"",
-                path_buffer);
+                real_path);
 
         /* Init information to 0, lacking any alternative */
         file->size  = 0;
@@ -267,6 +266,9 @@ void guac_rdpdr_fs_close(guac_rdpdr_device* device, int file_id) {
     /* Close file */
     close(file->fd);
 
+    /* Free name */
+    free(file->absolute_path);
+
     /* Free ID back to pool */
     guac_pool_free_int(data->file_id_pool, file_id);
     data->open_files--;
@@ -302,3 +304,86 @@ const char* guac_rdpdr_fs_read_dir(guac_rdpdr_device* device, int file_id) {
 
 }
 
+int guac_rdpdr_fs_normalize_path(const char* path, char* abs_path) {
+
+    int i;
+    int path_depth = 0;
+    char path_component_data[GUAC_RDPDR_FS_MAX_PATH];
+    const char* path_components[64];
+
+    const char** current_path_component      = &(path_components[0]);
+    const char*  current_path_component_data = &(path_component_data[0]);
+
+    /* If original path is not absolute, normalization fails */
+    if (path[0] != '\\' && path[0] != '/')
+        return 1;
+
+    /* Skip past leading slash */
+    path++;
+
+    /* Copy path into component data for parsing */
+    strncpy(path_component_data, path, GUAC_RDPDR_FS_MAX_PATH-1);
+
+    /* Find path components within path */
+    for (i=0; i<GUAC_RDPDR_FS_MAX_PATH; i++) {
+
+        /* If current character is a path separator, parse as component */
+        char c = path_component_data[i];
+        if (c == '/' || c == '\\' || c == 0) {
+
+            /* Terminate current component */
+            path_component_data[i] = 0;
+
+            /* If component refers to parent, just move up in depth */
+            if (strcmp(current_path_component_data, "..") == 0) {
+                if (path_depth > 0)
+                    path_depth--;
+            }
+
+            /* Otherwise, if component not current directory, add to list */
+            else if (strcmp(current_path_component_data, ".") != 0)
+                path_components[path_depth++] = current_path_component_data;
+
+            /* If end of string, stop */
+            if (c == 0)
+                break;
+
+            /* Update start of next component */
+            current_path_component_data = &(path_component_data[i+1]);
+
+        } /* end if separator */
+
+    } /* end for each character */
+
+    /* If no components, the path could not be parsed */
+    if (path_depth == 0)
+        return 1;
+
+    /* Ensure last component is null-terminated */
+    path_component_data[i] = 0;
+
+    /* Convert components back into path */
+    for (; path_depth > 0; path_depth--) {
+
+        const char* filename = *(current_path_component++);
+
+        /* Add separator */
+        *(abs_path++) = '\\';
+
+        /* Copy string */
+        while (*filename != 0)
+            *(abs_path++) = *(filename++);
+
+    }
+
+    /* Terminate absolute path */
+    *(abs_path++) = 0;
+    return 0;
+
+}
+
+int guac_rdpdr_fs_convert_path(const char* parent, const char* rel_path, char* abs_path) {
+    /* STUB */
+    return 0;
+}
+

src/protocols/rdp/guac_rdpdr/rdpdr_fs.h

@@ -160,6 +160,11 @@ typedef enum guac_rdpdr_fs_file_type {
  */
 typedef struct guac_rdpdr_fs_file {
 
+    /**
+     * The absolute path, including filename, of this file.
+     */
+    char* absolute_path;
+
     /**
      * The type of this file.
      */
@@ -232,6 +237,12 @@ typedef struct guac_rdpdr_fs_data {
  */
 void guac_rdpdr_register_fs(guac_rdpdrPlugin* rdpdr);
 
+/**
+ * Converts the given relative path to an absolute path based on the given
+ * parent path. If the path cannot be converted, non-zero is returned.
+ */
+int guac_rdpdr_fs_convert_path(const char* parent, const char* rel_path, char* abs_path);
+
 /**
  * Returns the next available file ID, or an error code less than zero
  * if an error occurs.
@@ -244,6 +255,17 @@ int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path,
  */
 void guac_rdpdr_fs_close(guac_rdpdr_device* device, int file_id);
 
+/**
+ * Given an arbitrary path, which may contain ".." and ".", creates an
+ * absolute path which does NOT contain ".." or ".".
+ */
+int guac_rdpdr_fs_normalize_path(const char* path, char* abs_path);
+
+/**
+ * Given a parent path and a relative path, produces a normalized absolute path.
+ */
+int guac_rdpdr_fs_convert_path(const char* parent, const char* rel_path, char* abs_path);
+
 /**
  * Returns the next filename within the directory having the given file ID,
  * or NULL if no more files.

src/protocols/rdp/guac_rdpdr/rdpdr_fs_messages.c

@@ -275,12 +275,11 @@ void guac_rdpdr_fs_process_notify_change_directory(guac_rdpdr_device* device,
 void guac_rdpdr_fs_process_query_directory(guac_rdpdr_device* device, wStream* input_stream,
         int file_id, int completion_id) {
 
-    /*guac_rdpdr_fs_data* data = (guac_rdpdr_fs_data*) device->data;
-    guac_rdpdr_fs_file* file = &(data->files[file_id]);*/
-
     int fs_information_class, initial_query;
     int path_length;
 
+    const char* entry_name;
+
     /* Read main header */
     Stream_Read_UINT32(input_stream, fs_information_class);
     Stream_Read_UINT8(input_stream,  initial_query);
@@ -298,17 +297,18 @@ void guac_rdpdr_fs_process_query_directory(guac_rdpdr_device* device, wStream* i
                 "Received initial dir query - class=0x%x, path_length=%i, path=%s",
                 fs_information_class, path_length, path);
 
-        /* Open directory */
-        /*file->dir = fdopendir(file->fd);*/
-
-        /* FIXME: Handle error */
-
     }
     else
         guac_client_log_info(device->rdpdr->client,
                 "Received continued dir query - class=0x%x",
                 fs_information_class);
 
+    /* If entry exists, call appriate handler to send data */
+    entry_name = guac_rdpdr_fs_read_dir(device, file_id);
+    if (entry_name != NULL) {
+
+        guac_client_log_info(device->rdpdr->client, "NAME: %s", entry_name);
+
         /* Dispatch to appropriate class-specific handler */
         switch (fs_information_class) {
 
@@ -337,6 +337,11 @@ void guac_rdpdr_fs_process_query_directory(guac_rdpdr_device* device, wStream* i
                         "Unknown dir information class: 0x%x", fs_information_class);
         }
 
+    }
+
+    /* Otherwise, send STATUS_NO_MORE_FILES */
+    else {
+    }
 
 }