lib/addns: move DNS client library to the main directory.

Guenther

1 files changed, 530 insertions, 0 deletions

diff --git a/lib/addns/dnsmarshall.c b/lib/addns/dnsmarshall.c
new file mode 100644
index 0000000000..5530290c57
--- /dev/null
+++ b/lib/addns/dnsmarshall.c
@@ -0,0 +1,530 @@
+/*
+  Linux DNS client library implementation
+  Copyright (C) 2006 Gerald Carter <jerry@samba.org>
+
+     ** NOTE! The following LGPL license applies to the libaddns
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+
+  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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "dns.h"
+#include "assert.h"
+
+struct dns_buffer *dns_create_buffer(TALLOC_CTX *mem_ctx)
+{
+	struct dns_buffer *result;
+
+	if (!(result = talloc(mem_ctx, struct dns_buffer))) {
+		return NULL;
+	}
+
+	result->offset = 0;
+	result->error = ERROR_DNS_SUCCESS;
+	
+	/*
+	 * Small inital size to excercise the realloc code
+	 */
+	result->size = 2;
+
+	if (!(result->data = TALLOC_ARRAY(result, uint8, result->size))) {
+		TALLOC_FREE(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+void dns_marshall_buffer(struct dns_buffer *buf, const uint8 *data,
+			 size_t len)
+{
+	if (!ERR_DNS_IS_OK(buf->error)) return;
+
+	if (buf->offset + len < buf->offset) {
+		/*
+		 * Wraparound!
+		 */
+		buf->error = ERROR_DNS_INVALID_PARAMETER;
+		return;
+	}
+
+	if ((buf->offset + len) > 0xffff) {
+		/*
+		 * Only 64k possible
+		 */
+		buf->error = ERROR_DNS_INVALID_PARAMETER;
+		return;
+	}
+		
+	if (buf->offset + len > buf->size) {
+		size_t new_size = buf->offset + len;
+		uint8 *new_data;
+
+		/*
+		 * Don't do too many reallocs, round up to some multiple
+		 */
+
+		new_size += (64 - (new_size % 64));
+
+		if (!(new_data = TALLOC_REALLOC_ARRAY(buf, buf->data, uint8,
+						      new_size))) {
+			buf->error = ERROR_DNS_NO_MEMORY;
+			return;
+		}
+
+		buf->size = new_size;
+		buf->data = new_data;
+	}
+
+	memcpy(buf->data + buf->offset, data, len);
+	buf->offset += len;
+	return;
+}
+
+void dns_marshall_uint16(struct dns_buffer *buf, uint16 val)
+{
+	uint16 n_val = htons(val);
+	dns_marshall_buffer(buf, (uint8 *)&n_val, sizeof(n_val));
+}
+
+void dns_marshall_uint32(struct dns_buffer *buf, uint32 val)
+{
+	uint32 n_val = htonl(val);
+	dns_marshall_buffer(buf, (uint8 *)&n_val, sizeof(n_val));
+}
+
+void dns_unmarshall_buffer(struct dns_buffer *buf, uint8 *data,
+			   size_t len)
+{
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	if ((len > buf->size) || (buf->offset + len > buf->size)) {
+		buf->error = ERROR_DNS_INVALID_MESSAGE;
+		return;
+	}
+
+	memcpy((void *)data, (const void *)(buf->data + buf->offset), len);
+	buf->offset += len;
+
+	return;
+}
+
+void dns_unmarshall_uint16(struct dns_buffer *buf, uint16 *val)
+{
+	uint16 n_val;
+
+	dns_unmarshall_buffer(buf, (uint8 *)&n_val, sizeof(n_val));
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	*val = ntohs(n_val);
+}
+
+void dns_unmarshall_uint32(struct dns_buffer *buf, uint32 *val)
+{
+	uint32 n_val;
+
+	dns_unmarshall_buffer(buf, (uint8 *)&n_val, sizeof(n_val));
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	*val = ntohl(n_val);
+}
+
+void dns_marshall_domain_name(struct dns_buffer *buf,
+			      const struct dns_domain_name *name)
+{
+	struct dns_domain_label *label;
+	char end_char = '\0';
+
+	/*
+	 * TODO: Implement DNS compression
+	 */
+
+	for (label = name->pLabelList; label != NULL; label = label->next) {
+		uint8 len = label->len;
+
+		dns_marshall_buffer(buf, (uint8 *)&len, sizeof(len));
+		if (!ERR_DNS_IS_OK(buf->error)) return;
+
+		dns_marshall_buffer(buf, (uint8 *)label->label, len);
+		if (!ERR_DNS_IS_OK(buf->error)) return;
+	}
+
+	dns_marshall_buffer(buf, (uint8 *)&end_char, 1);
+}
+
+static void dns_unmarshall_label(TALLOC_CTX *mem_ctx,
+				 int level,
+				 struct dns_buffer *buf,
+				 struct dns_domain_label **plabel)
+{
+	struct dns_domain_label *label;
+	uint8 len;
+
+	if (!ERR_DNS_IS_OK(buf->error)) return;
+
+	if (level > 128) {
+		/*
+		 * Protect against recursion
+		 */
+		buf->error = ERROR_DNS_INVALID_MESSAGE;
+		return;
+	}
+
+	dns_unmarshall_buffer(buf, &len, sizeof(len));
+	if (!ERR_DNS_IS_OK(buf->error)) return;
+
+	if (len == 0) {
+		*plabel = NULL;
+		return;
+	}
+
+	if ((len & 0xc0) == 0xc0) {
+		/*
+		 * We've got a compressed name. Build up a new "fake" buffer
+		 * and using the calculated offset.
+		 */
+		struct dns_buffer new_buf;
+		uint8 low;
+
+		dns_unmarshall_buffer(buf, &low, sizeof(low));
+		if (!ERR_DNS_IS_OK(buf->error)) return;
+
+		new_buf = *buf;
+		new_buf.offset = len & 0x3f;
+		new_buf.offset <<= 8;
+		new_buf.offset |= low;
+
+		dns_unmarshall_label(mem_ctx, level+1, &new_buf, plabel);
+		buf->error = new_buf.error;
+		return;
+	}
+
+	if ((len & 0xc0) != 0) {
+		buf->error = ERROR_DNS_INVALID_NAME;
+		return;
+	}
+
+	if (!(label = talloc(mem_ctx, struct dns_domain_label))) {
+		buf->error = ERROR_DNS_NO_MEMORY;
+		return;
+	}
+
+	label->len = len;
+
+	if (!(label->label = TALLOC_ARRAY(label, char, len+1))) {
+		buf->error = ERROR_DNS_NO_MEMORY;
+		goto error;
+	}
+
+	dns_unmarshall_buffer(buf, (uint8 *)label->label, len);
+	if (!ERR_DNS_IS_OK(buf->error)) goto error;
+
+	dns_unmarshall_label(label, level+1, buf, &label->next);
+	if (!ERR_DNS_IS_OK(buf->error)) goto error;
+
+	*plabel = label;
+	return;
+
+ error:
+	TALLOC_FREE(label);
+	return;
+}
+
+void dns_unmarshall_domain_name(TALLOC_CTX *mem_ctx,
+				struct dns_buffer *buf,
+				struct dns_domain_name **pname)
+{
+	struct dns_domain_name *name;
+
+	if (!ERR_DNS_IS_OK(buf->error)) return;
+
+	if (!(name = talloc(mem_ctx, struct dns_domain_name))) {
+		buf->error = ERROR_DNS_NO_MEMORY;
+		return;
+	}
+
+	dns_unmarshall_label(name, 0, buf, &name->pLabelList);
+
+	if (!ERR_DNS_IS_OK(buf->error)) {
+		return;
+	}
+
+	*pname = name;
+	return;
+}
+
+static void dns_marshall_question(struct dns_buffer *buf,
+				  const struct dns_question *q)
+{
+	dns_marshall_domain_name(buf, q->name);
+	dns_marshall_uint16(buf, q->q_type);
+	dns_marshall_uint16(buf, q->q_class);
+}
+
+static void dns_unmarshall_question(TALLOC_CTX *mem_ctx,
+				    struct dns_buffer *buf,
+				    struct dns_question **pq)
+{
+	struct dns_question *q;
+
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	if (!(q = talloc(mem_ctx, struct dns_question))) {
+		buf->error = ERROR_DNS_NO_MEMORY;
+		return;
+	}
+
+	dns_unmarshall_domain_name(q, buf, &q->name);
+	dns_unmarshall_uint16(buf, &q->q_type);
+	dns_unmarshall_uint16(buf, &q->q_class);
+
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	*pq = q;
+}
+
+static void dns_marshall_rr(struct dns_buffer *buf,
+			    const struct dns_rrec *r)
+{
+	dns_marshall_domain_name(buf, r->name);
+	dns_marshall_uint16(buf, r->type);
+	dns_marshall_uint16(buf, r->r_class);
+	dns_marshall_uint32(buf, r->ttl);
+	dns_marshall_uint16(buf, r->data_length);
+	dns_marshall_buffer(buf, r->data, r->data_length);
+}
+
+static void dns_unmarshall_rr(TALLOC_CTX *mem_ctx,
+			      struct dns_buffer *buf,
+			      struct dns_rrec **pr)
+{
+	struct dns_rrec *r;
+
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	if (!(r = talloc(mem_ctx, struct dns_rrec))) {
+		buf->error = ERROR_DNS_NO_MEMORY;
+		return;
+	}
+
+	dns_unmarshall_domain_name(r, buf, &r->name);
+	dns_unmarshall_uint16(buf, &r->type);
+	dns_unmarshall_uint16(buf, &r->r_class);
+	dns_unmarshall_uint32(buf, &r->ttl);
+	dns_unmarshall_uint16(buf, &r->data_length);
+	r->data = NULL;
+
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	if (r->data_length != 0) {
+		if (!(r->data = TALLOC_ARRAY(r, uint8, r->data_length))) {
+			buf->error = ERROR_DNS_NO_MEMORY;
+			return;
+		}
+		dns_unmarshall_buffer(buf, r->data, r->data_length);
+	}
+
+	if (!(ERR_DNS_IS_OK(buf->error))) return;
+
+	*pr = r;
+}
+
+DNS_ERROR dns_marshall_request(TALLOC_CTX *mem_ctx,
+			       const struct dns_request *req,
+			       struct dns_buffer **pbuf)
+{
+	struct dns_buffer *buf;
+	uint16 i;
+
+	if (!(buf = dns_create_buffer(mem_ctx))) {
+		return ERROR_DNS_NO_MEMORY;
+	}
+
+	dns_marshall_uint16(buf, req->id);
+	dns_marshall_uint16(buf, req->flags);
+	dns_marshall_uint16(buf, req->num_questions);
+	dns_marshall_uint16(buf, req->num_answers);
+	dns_marshall_uint16(buf, req->num_auths);
+	dns_marshall_uint16(buf, req->num_additionals);
+
+	for (i=0; i<req->num_questions; i++) {
+		dns_marshall_question(buf, req->questions[i]);
+	}
+	for (i=0; i<req->num_answers; i++) {
+		dns_marshall_rr(buf, req->answers[i]);
+	}
+	for (i=0; i<req->num_auths; i++) {
+		dns_marshall_rr(buf, req->auths[i]);
+	}
+	for (i=0; i<req->num_additionals; i++) {
+		dns_marshall_rr(buf, req->additionals[i]);
+	}
+
+	if (!ERR_DNS_IS_OK(buf->error)) {
+		DNS_ERROR err = buf->error;
+		TALLOC_FREE(buf);
+		return err;
+	}
+
+	*pbuf = buf;
+	return ERROR_DNS_SUCCESS;
+}
+
+DNS_ERROR dns_unmarshall_request(TALLOC_CTX *mem_ctx,
+				 struct dns_buffer *buf,
+				 struct dns_request **preq)
+{
+	struct dns_request *req;
+	uint16 i;
+	DNS_ERROR err;
+
+	if (!(req = TALLOC_ZERO_P(mem_ctx, struct dns_request))) {
+		return ERROR_DNS_NO_MEMORY;
+	}
+
+	dns_unmarshall_uint16(buf, &req->id);
+	dns_unmarshall_uint16(buf, &req->flags);
+	dns_unmarshall_uint16(buf, &req->num_questions);
+	dns_unmarshall_uint16(buf, &req->num_answers);
+	dns_unmarshall_uint16(buf, &req->num_auths);
+	dns_unmarshall_uint16(buf, &req->num_additionals);
+
+	if (!ERR_DNS_IS_OK(buf->error)) goto error;
+
+	err = ERROR_DNS_NO_MEMORY;
+
+	if ((req->num_questions != 0) &&
+	    !(req->questions = TALLOC_ARRAY(req, struct dns_question *,
+					    req->num_questions))) {
+		goto error;
+	}
+	if ((req->num_answers != 0) &&
+	    !(req->answers = TALLOC_ARRAY(req, struct dns_rrec *,
+					  req->num_answers))) {
+		goto error;
+	}
+	if ((req->num_auths != 0) &&
+	    !(req->auths = TALLOC_ARRAY(req, struct dns_rrec *,
+					req->num_auths))) {
+		goto error;
+	}
+	if ((req->num_additionals != 0) &&
+	    !(req->additionals = TALLOC_ARRAY(req, struct dns_rrec *,
+					      req->num_additionals))) {
+		goto error;
+	}
+
+	for (i=0; i<req->num_questions; i++) {
+		dns_unmarshall_question(req->questions, buf,
+					&req->questions[i]);
+	}
+	for (i=0; i<req->num_answers; i++) {
+		dns_unmarshall_rr(req->answers, buf,
+				  &req->answers[i]);
+	}
+	for (i=0; i<req->num_auths; i++) {
+		dns_unmarshall_rr(req->auths, buf,
+				  &req->auths[i]);
+	}
+	for (i=0; i<req->num_additionals; i++) {
+		dns_unmarshall_rr(req->additionals, buf,
+				  &req->additionals[i]);
+	}
+
+	if (!ERR_DNS_IS_OK(buf->error)) {
+		err = buf->error;
+		goto error;
+	}
+
+	*preq = req;
+	return ERROR_DNS_SUCCESS;
+
+ error:
+	err = buf->error;
+	TALLOC_FREE(req);
+	return err;
+}
+
+struct dns_request *dns_update2request(struct dns_update_request *update)
+{
+	struct dns_request *req;
+
+	/*
+	 * This is a non-specified construct that happens to work on Linux/gcc
+	 * and I would expect it to work everywhere else. dns_request and
+	 * dns_update_request are essentially the same structures with
+	 * different names, so any difference would mean that the compiler
+	 * applied two different variations of padding given the same types in
+	 * the structures.
+	 */
+
+	req = (struct dns_request *)(void *)update;
+
+	/*
+	 * The assert statement here looks like we could do the equivalent
+	 * assignments to get portable, but it would mean that we have to
+	 * allocate the dns_question record for the dns_zone records. We
+	 * assume that if this assert works then the same holds true for
+	 * dns_zone<>dns_question as well.
+	 */
+
+#ifdef DEVELOPER
+	assert((req->id == update->id) && (req->flags == update->flags) &&
+	       (req->num_questions == update->num_zones) &&
+	       (req->num_answers == update->num_preqs) &&
+	       (req->num_auths == update->num_updates) &&
+	       (req->num_additionals == update->num_additionals) &&
+	       (req->questions ==
+		(struct dns_question **)(void *)update->zones) &&
+	       (req->answers == update->preqs) &&
+	       (req->auths == update->updates) &&
+	       (req->additionals == update->additionals));
+#endif
+
+	return req;
+}
+
+struct dns_update_request *dns_request2update(struct dns_request *request)
+{
+	/*
+	 * For portability concerns see dns_update2request;
+	 */
+	return (struct dns_update_request *)(void *)request;
+}
+
+DNS_ERROR dns_marshall_update_request(TALLOC_CTX *mem_ctx,
+				      struct dns_update_request *update,
+				      struct dns_buffer **pbuf)
+{
+	return dns_marshall_request(mem_ctx, dns_update2request(update), pbuf);
+}
+
+DNS_ERROR dns_unmarshall_update_request(TALLOC_CTX *mem_ctx,
+					struct dns_buffer *buf,
+					struct dns_update_request **pupreq)
+{
+	/*
+	 * See comments above about portability. If the above works, this will
+	 * as well.
+	 */
+
+	return dns_unmarshall_request(mem_ctx, buf,
+				      (struct dns_request **)(void *)pupreq);
+}
+
+uint16 dns_response_code(uint16 flags)
+{
+	return flags & 0xF;
+}