Imported Upstream version 2.6.1

[debian/amanda] / xfer-src / filter-xor.c

diff --git a/xfer-src/filter-xor.c b/xfer-src/filter-xor.c
new file mode 100644 (file)
index 0000000..613b972
--- /dev/null
+++ b/xfer-src/filter-xor.c
@@ -0,0 +1,191 @@
+/*
+ * Amanda, The Advanced Maryland Automatic Network Disk Archiver
+ * Copyright (c) 2008 Zmanda Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "amxfer.h"
+#include "amanda.h"
+
+/*
+ * Class declaration
+ *
+ * This declaration is entirely private; nothing but xfer_filter_xor() references
+ * it directly.
+ */
+
+GType xfer_filter_xor_get_type(void);
+#define XFER_FILTER_XOR_TYPE (xfer_filter_xor_get_type())
+#define XFER_FILTER_XOR(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_filter_xor_get_type(), XferFilterXor)
+#define XFER_FILTER_XOR_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_filter_xor_get_type(), XferFilterXor const)
+#define XFER_FILTER_XOR_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), xfer_filter_xor_get_type(), XferFilterXorClass)
+#define IS_XFER_FILTER_XOR(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), xfer_filter_xor_get_type ())
+#define XFER_FILTER_XOR_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), xfer_filter_xor_get_type(), XferFilterXorClass)
+
+static GObjectClass *parent_class = NULL;
+
+/*
+ * Main object structure
+ */
+
+typedef struct XferFilterXor {
+    XferElement __parent__;
+
+    char xor_key;
+} XferFilterXor;
+
+/*
+ * Class definition
+ */
+
+typedef struct {
+    XferElementClass __parent__;
+} XferFilterXorClass;
+
+
+/*
+ * Utilities
+ */
+
+static void
+apply_xor(
+    char *buf,
+    size_t len,
+    char xor_key)
+{
+    size_t i;
+
+    /* Apply XOR.  This is a pretty sophisticated encryption algorithm! */
+    for (i = 0; i < len; i++) {
+       buf[i] ^= xor_key;
+    }
+}
+
+/*
+ * Implementation
+ */
+
+static gpointer
+pull_buffer_impl(
+    XferElement *elt,
+    size_t *size)
+{
+    XferFilterXor *self = (XferFilterXor *)elt;
+    char *buf;
+
+    if (elt->cancelled) {
+       /* drain our upstream only if we're expecting an EOF */
+       if (elt->expect_eof) {
+           xfer_element_drain_by_pulling(XFER_ELEMENT(self)->upstream);
+       }
+
+       /* return an EOF */
+       *size = 0;
+       return NULL;
+    }
+
+    /* get a buffer from upstream, xor it, and hand it back */
+    buf = xfer_element_pull_buffer(XFER_ELEMENT(self)->upstream, size);
+    if (buf)
+       apply_xor(buf, *size, self->xor_key);
+    return buf;
+}
+
+static void
+push_buffer_impl(
+    XferElement *elt,
+    gpointer buf,
+    size_t len)
+{
+    XferFilterXor *self = (XferFilterXor *)elt;
+
+    /* drop the buffer if we've been cancelled */
+    if (elt->cancelled) {
+       amfree(buf);
+       return;
+    }
+
+    /* xor the given buffer and pass it downstream */
+    if (buf)
+       apply_xor(buf, len, self->xor_key);
+
+    xfer_element_push_buffer(XFER_ELEMENT(self)->downstream, buf, len);
+}
+
+static void
+instance_init(
+    XferElement *elt)
+{
+    elt->can_generate_eof = TRUE;
+}
+
+static void
+class_init(
+    XferFilterXorClass * selfc)
+{
+    XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
+    static xfer_element_mech_pair_t mech_pairs[] = {
+       { XFER_MECH_PULL_BUFFER, XFER_MECH_PULL_BUFFER, 1, 0},
+       { XFER_MECH_PUSH_BUFFER, XFER_MECH_PUSH_BUFFER, 1, 0},
+       { XFER_MECH_NONE, XFER_MECH_NONE, 0, 0},
+    };
+
+    klass->push_buffer = push_buffer_impl;
+    klass->pull_buffer = pull_buffer_impl;
+
+    klass->perl_class = "Amanda::Xfer::Filter::Xor";
+    klass->mech_pairs = mech_pairs;
+
+    parent_class = g_type_class_peek_parent(selfc);
+}
+
+GType
+xfer_filter_xor_get_type (void)
+{
+    static GType type = 0;
+
+    if G_UNLIKELY(type == 0) {
+        static const GTypeInfo info = {
+            sizeof (XferFilterXorClass),
+            (GBaseInitFunc) NULL,
+            (GBaseFinalizeFunc) NULL,
+            (GClassInitFunc) class_init,
+            (GClassFinalizeFunc) NULL,
+            NULL /* class_data */,
+            sizeof (XferFilterXor),
+            0 /* n_preallocs */,
+            (GInstanceInitFunc) instance_init,
+            NULL
+        };
+
+        type = g_type_register_static (XFER_ELEMENT_TYPE, "XferFilterXor", &info, 0);
+    }
+
+    return type;
+}
+
+/* create an element of this class; prototype is in xfer-element.h */
+XferElement *
+xfer_filter_xor(
+    unsigned char xor_key)
+{
+    XferFilterXor *xfx = (XferFilterXor *)g_object_new(XFER_FILTER_XOR_TYPE, NULL);
+    XferElement *elt = XFER_ELEMENT(xfx);
+
+    xfx->xor_key = xor_key;
+
+    return elt;
+}