s4:ldb Add ldb_ldif_write_string() and python wrappers

This allows us to turn a python LdbMessage back into a string.

Andrew Bartlett

4 files changed, 95 insertions, 1 deletions

diff --git a/source4/lib/ldb/common/ldb_ldif.c b/source4/lib/ldb/common/ldb_ldif.c
index d890ff8300..30370e6999 100644
--- a/source4/lib/ldb/common/ldb_ldif.c
+++ b/source4/lib/ldb/common/ldb_ldif.c
@@ -759,3 +759,43 @@ int ldb_ldif_write_file(struct ldb_context *ldb, FILE *f, const struct ldb_ldif
 	state.f = f;
 	return ldb_ldif_write(ldb, fprintf_file, &state, ldif);
 }
+
+/*
+  wrapper around ldif_write() for a string
+*/
+struct ldif_write_string_state {
+	char *string;
+};
+
+static int ldif_printf_string(void *private_data, const char *fmt, ...) PRINTF_ATTRIBUTE(2, 3);
+
+static int ldif_printf_string(void *private_data, const char *fmt, ...)
+{
+	struct ldif_write_string_state *state =
+		(struct ldif_write_string_state *)private_data;
+	va_list ap;
+	size_t oldlen = strlen(state->string);
+	va_start(ap, fmt);
+	
+	state->string = talloc_vasprintf_append(state->string, fmt, ap);
+	va_end(ap);
+	if (!state->string) {
+		return -1;
+	}
+		
+	return strlen(state->string) - oldlen;
+}
+
+char *ldb_ldif_write_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, 
+			    const struct ldb_ldif *ldif)
+{
+	struct ldif_write_string_state state;
+	state.string = talloc_strdup(mem_ctx, "");
+	if (!state.string) {
+		return NULL;
+	}
+	if (ldb_ldif_write(ldb, ldif_printf_string, &state, ldif) == -1) {
+		return NULL;
+	}
+	return state.string;
+}
diff --git a/source4/lib/ldb/include/ldb.h b/source4/lib/ldb/include/ldb.h
index 20f0f9cc5a..8972fc83e9 100644
--- a/source4/lib/ldb/include/ldb.h
+++ b/source4/lib/ldb/include/ldb.h
@@ -1450,6 +1450,20 @@ struct ldb_ldif *ldb_ldif_read_string(struct ldb_context *ldb, const char **s);
 int ldb_ldif_write_file(struct ldb_context *ldb, FILE *f, const struct ldb_ldif *msg);
 
 /**
+   Write an LDIF message to a string
+
+   \param ldb the ldb context (from ldb_init())
+   \param mem_ctx the talloc context on which to attach the string)
+   \param msg the message to write out
+
+   \return the string containing the LDIF, or NULL on error
+
+   \sa ldb_ldif_read_string for the reader equivalent to this function.
+*/
+char * ldb_ldif_write_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, 
+			  const struct ldb_ldif *msg);
+
+/**
    Base64 encode a buffer
 
    \param mem_ctx the memory context that the result is allocated
diff --git a/source4/lib/ldb/pyldb.c b/source4/lib/ldb/pyldb.c
index 94415c8c31..3f7fa2f395 100644
--- a/source4/lib/ldb/pyldb.c
+++ b/source4/lib/ldb/pyldb.c
@@ -813,6 +813,41 @@ static PyObject *ldb_ldif_to_pyobject(struct ldb_ldif *ldif)
 }
 
 
+static PyObject *py_ldb_write_ldif(PyLdbMessageObject *self, PyObject *args)
+{
+	int changetype;
+	PyObject *py_msg;
+	struct ldb_ldif ldif;
+	PyObject *ret;
+	char *string;
+	TALLOC_CTX *mem_ctx;
+
+	if (!PyArg_ParseTuple(args, "Oi", &py_msg, &changetype))
+		return NULL;
+
+	if (!PyLdbMessage_Check(py_msg)) {
+		PyErr_SetString(PyExc_TypeError, "Expected Ldb Message for msg");
+		return NULL;
+	}
+
+	ldif.msg = PyLdbMessage_AsMessage(py_msg);
+	ldif.changetype = changetype;
+
+	mem_ctx = talloc_new(NULL);
+
+	string = ldb_ldif_write_string(PyLdb_AsLdbContext(self), mem_ctx, &ldif);
+	if (!string) {
+		PyErr_SetString(PyExc_KeyError, "Failed to generate LDIF");
+		return NULL;
+	}
+
+	ret = PyString_FromString(string);
+
+	talloc_free(mem_ctx);
+
+	return ret;
+}
+
 static PyObject *py_ldb_parse_ldif(PyLdbObject *self, PyObject *args)
 {
 	PyObject *list;
@@ -1116,6 +1151,9 @@ static PyMethodDef py_ldb_methods[] = {
 	{ "parse_ldif", (PyCFunction)py_ldb_parse_ldif, METH_VARARGS,
 		"S.parse_ldif(ldif) -> iter(messages)\n"
 		"Parse a string formatted using LDIF." },
+	{ "write_ldif", (PyCFunction)py_ldb_write_ldif, METH_VARARGS,
+		"S.write_ldif(message, changetype) -> ldif\n"
+		"Print the message as a string formatted using LDIF." },
 	{ "msg_diff", (PyCFunction)py_ldb_msg_diff, METH_VARARGS,
 		"S.msg_diff(Message) -> Message\n"
 		"Return an LDB Message of the difference between two Message objects." },
diff --git a/source4/lib/ldb/tests/python/api.py b/source4/lib/ldb/tests/python/api.py
index 9bcb225190..88983ac738 100755
--- a/source4/lib/ldb/tests/python/api.py
+++ b/source4/lib/ldb/tests/python/api.py
@@ -402,7 +402,9 @@ class DnTests(unittest.TestCase):
         msg = msgs.next()
         self.assertEquals("foo=bar", str(msg[1].dn))
         self.assertTrue(isinstance(msg[1], ldb.Message))
-
+        ldif = self.ldb.write_ldif(msg[1], ldb.CHANGETYPE_NONE)
+        self.assertEquals("dn: foo=bar\n\n", ldif)
+        
     def test_parse_ldif_more(self):
         msgs = self.ldb.parse_ldif("dn: foo=bar\n\n\ndn: bar=bar")
         msg = msgs.next()