Actually resolve and open files.

src/protocols/rdp/guac_rdpdr/rdpdr_fs.c

@@ -35,6 +35,10 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
 #ifdef ENABLE_WINPR
 #include <winpr/stream.h>
 #else
@@ -51,27 +55,148 @@
 
 #include <freerdp/utils/svc_plugin.h>
 
-int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path) {
+/**
+ * Translates an absolute Windows path to an absolute path which is within the "drive path"
+ * specified in the connection settings.
+ */
+static char* __guac_rdpdr_fs_translate_path(guac_rdpdr_device* device,
+        const char* path, char* path_buffer) {
+
+    /* Get drive path */
+    rdp_guac_client_data* client_data = (rdp_guac_client_data*) device->rdpdr->client->data;
+    char* drive_path = client_data->settings.drive_path;
+
+    int i;
+
+    /* Start with path from settings */
+    for (i=0; i<GUAC_RDPDR_FS_MAX_PATH-1; i++) {
+
+        /* Copy character, break on end-of-string */
+        if ((*(path_buffer++) = *(drive_path++)) == 0)
+            break;
+
+    }
+
+    /* Translate path */
+    for (; i<GUAC_RDPDR_FS_MAX_PATH-1; i++) {
+
+        /* Stop at end of string */
+        char c = *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[i] = c;
+
+        /* Next path character */
+        path++;
+
+    }
+
+    /* Null terminator */
+    path_buffer[i] = 0;
+    return path_buffer;
+
+}
+
+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];
 
+    int fd;
     int file_id;
     guac_rdpdr_fs_file* file;
 
+    mode_t mode;
+    int flags = 0;
+
     /* If no files available, return too many open */
     if (data->open_files >= GUAC_RDPDR_FS_MAX_FILES)
         return GUAC_RDPDR_FS_ENFILE;
 
-    /* If path is empty, the file does not exist */
-    if (path[0] == '\0')
+    /* If path is empty or relative, the file does not exist */
+    if (path[0] != '\\')
         return GUAC_RDPDR_FS_ENOENT;
 
-    file->type = GUAC_RDPDR_FS_FILE;
-    /* STUB */
+    /* Translate access into mode */
+    if (access & ACCESS_FILE_READ_DATA) {
+        if (access & (ACCESS_FILE_WRITE_DATA | ACCESS_FILE_APPEND_DATA))
+            mode = O_RDWR;
+        else
+            mode = O_RDONLY;
+    }
+    else if (access & (ACCESS_FILE_WRITE_DATA | ACCESS_FILE_APPEND_DATA))
+        mode = O_WRONLY;
+    else
+        return GUAC_RDPDR_FS_ENOENT; /* FIXME: Replace with real return value */
 
-    /* Get file ID */
+    /* If append access requested, add appropriate option */
+    if (access & ACCESS_FILE_APPEND_DATA)
+        flags |= O_APPEND;
+
+    switch (create_disposition) {
+
+        /* Supersede (replace) if exists, otherwise create */
+        case DISP_FILE_SUPERSEDE:
+            flags |= O_TRUNC | O_CREAT;
+            break;
+
+        /* Open file if exists and do not overwrite, fail otherwise */
+        case DISP_FILE_OPEN:
+            flags |= O_APPEND;
+            break;
+
+        /* Create if not exist, fail otherwise */
+        case DISP_FILE_CREATE:
+            flags |= O_EXCL;
+            break;
+
+        /* Open if exists, create otherwise */
+        case DISP_FILE_OPEN_IF:
+            flags |= O_APPEND | O_CREAT;
+            break;
+
+        /* Overwrite if exists, fail otherwise */
+        case DISP_FILE_OVERWRITE:
+            /* No flag necessary - default functionality of open */
+            break;
+
+        /* Overwrite if exists, create otherwise */
+        case DISP_FILE_OVERWRITE_IF:
+            flags |= O_CREAT;
+            break;
+
+        /* Unrecognised disposition */
+        default:
+            return GUAC_RDPDR_FS_ENOENT; /* FIXME: Replace with real return value */
+
+    }
+
+    /* If path invalid, return no such file */
+    if (__guac_rdpdr_fs_translate_path(device, path, path_buffer) == NULL)
+        return GUAC_RDPDR_FS_ENOENT;
+
+    guac_client_log_info(device->rdpdr->client, "Path translated to \"%s\"", path_buffer);
+
+    /* Open file */
+    fd = open(path_buffer, flags, mode);
+    if (fd == -1)
+        return GUAC_RDPDR_FS_ENOENT;
+
+    /* Get file ID, init file */
     file_id = guac_pool_next_int(data->file_id_pool);
     file = &(data->files[file_id]);
+    file->fd = fd;
 
     data->open_files++;
 

src/protocols/rdp/guac_rdpdr/rdpdr_fs.h

@@ -60,6 +60,11 @@
  */
 #define GUAC_RDPDR_FS_MAX_FILES 128
 
+/**
+ * The maximum number of bytes in a path string.
+ */
+#define GUAC_RDPDR_FS_MAX_PATH 4096
+
 /**
  * Error code returned when no more file IDs can be allocated.
  */
@@ -70,6 +75,25 @@
  */
 #define GUAC_RDPDR_FS_ENOENT -2
 
+/*
+ * Access constants.
+ */
+#define ACCESS_FILE_READ_DATA    0x00000001
+#define ACCESS_FILE_WRITE_DATA   0x00000002
+#define ACCESS_FILE_APPEND_DATA  0x00000004
+#define ACCESS_DELETE            0x00010000
+
+/*
+ * Create disposition constants.
+ */
+
+#define DISP_FILE_SUPERSEDE    0x00000000
+#define DISP_FILE_OPEN         0x00000001
+#define DISP_FILE_CREATE       0x00000002
+#define DISP_FILE_OPEN_IF      0x00000003
+#define DISP_FILE_OVERWRITE    0x00000004
+#define DISP_FILE_OVERWRITE_IF 0x00000005
+
 /*
  * Information constants.
  */
@@ -102,36 +126,11 @@
  */
 #define WINDOWS_TIME(t) ((t - ((uint64_t) 11644473600)) * 10000000)
 
-/**
- * Enumeration of all supported file types.
- */
-typedef enum guac_rdpdr_fs_file_type {
-
-    /**
-     * A regular file - either a file or directory.
-     */
-    GUAC_RDPDR_FS_FILE,
-
-    /**
-     * A disk device - here, this is always virtual, and always the containing
-     * volume (the Guacamole drive).
-     */
-    GUAC_RDPDR_FS_VOLUME,
-
-} guac_rdpdr_fs_file_type;
-
 /**
  * An arbitrary file on the virtual filesystem of the Guacamole drive.
  */
 typedef struct guac_rdpdr_fs_file {
 
-    /**
-     * The type of this file - either a FILE (file or directory) or a
-     * VOLUME (virtual file, represents the virtual device represented by
-     * the Guacamole drive).
-     */
-    guac_rdpdr_fs_file_type type;
-
     /**
      * Associated local file descriptor.
      */
@@ -170,7 +169,8 @@ void guac_rdpdr_register_fs(guac_rdpdrPlugin* rdpdr);
 /**
  * Returns the next available file ID, or -1 if none available.
  */
-int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path);
+int guac_rdpdr_fs_open(guac_rdpdr_device* device, const char* path,
+        int access, int create_disposition);
 
 /**
  * Frees the given file ID, allowing future open operations to reuse it.

src/protocols/rdp/guac_rdpdr/rdpdr_fs_messages.c

@@ -78,7 +78,7 @@ void guac_rdpdr_fs_process_create(guac_rdpdr_device* device,
     guac_rdp_utf16_to_utf8(Stream_Pointer(input_stream), path, path_length/2 - 1);
 
     /* Open file */
-    file_id = guac_rdpdr_fs_open(device, path);
+    file_id = guac_rdpdr_fs_open(device, path, desired_access, create_disposition);
 
     /* Write header */
     Stream_Write_UINT16(output_stream, RDPDR_CTYP_CORE);