--- /dev/null
+/*
+ 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;
+}
git.samba.org / sfrench / samba-autobuild / .git / blobdiff