--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+
+ manipulate dns name structures
+
+ Copyright (C) 2010 Kai Blin <kai@samba.org>
+
+ Heavily based on nbtname.c which is:
+
+ Copyright (C) Andrew Tridgell 2005
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ see rfc1002 for the detailed format of compressed names
+*/
+
+#include "includes.h"
+#include "librpc/gen_ndr/ndr_dns.h"
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "system/locale.h"
+#include "lib/util/util_net.h"
+
+/* don't allow an unlimited number of name components */
+#define MAX_COMPONENTS 10
+
+/**
+ print a dns string
+*/
+_PUBLIC_ void ndr_print_dns_string(struct ndr_print *ndr, const char *name, const char *s)
+{
+ ndr_print_string(ndr, name, s);
+}
+
+/*
+ pull one component of a dns_string
+*/
+static enum ndr_err_code ndr_pull_component(struct ndr_pull *ndr,
+ uint8_t **component,
+ uint32_t *offset,
+ uint32_t *max_offset)
+{
+ uint8_t len;
+ unsigned int loops = 0;
+ while (loops < 5) {
+ if (*offset >= ndr->data_size) {
+ return ndr_pull_error(ndr, NDR_ERR_STRING,
+ "BAD DNS NAME component");
+ }
+ len = ndr->data[*offset];
+ if (len == 0) {
+ *offset += 1;
+ *max_offset = MAX(*max_offset, *offset);
+ *component = NULL;
+ return NDR_ERR_SUCCESS;
+ }
+ if ((len & 0xC0) == 0xC0) {
+ /* its a label pointer */
+ if (1 + *offset >= ndr->data_size) {
+ return ndr_pull_error(ndr, NDR_ERR_STRING,
+ "BAD DNS NAME component");
+ }
+ *max_offset = MAX(*max_offset, *offset + 2);
+ *offset = ((len&0x3F)<<8) | ndr->data[1 + *offset];
+ *max_offset = MAX(*max_offset, *offset);
+ loops++;
+ continue;
+ }
+ if ((len & 0xC0) != 0) {
+ /* its a reserved length field */
+ return ndr_pull_error(ndr, NDR_ERR_STRING,
+ "BAD DNS NAME component");
+ }
+ if (*offset + len + 2 > ndr->data_size) {
+ return ndr_pull_error(ndr, NDR_ERR_STRING,
+ "BAD DNS NAME component");
+ }
+ *component = (uint8_t*)talloc_strndup(ndr, (const char *)&ndr->data[1 + *offset], len);
+ NDR_ERR_HAVE_NO_MEMORY(*component);
+ *offset += len + 1;
+ *max_offset = MAX(*max_offset, *offset);
+ return NDR_ERR_SUCCESS;
+ }
+
+ /* too many pointers */
+ return ndr_pull_error(ndr, NDR_ERR_STRING, "BAD DNS NAME component");
+}
+
+/**
+ pull a dns_string from the wire
+*/
+_PUBLIC_ enum ndr_err_code ndr_pull_dns_string(struct ndr_pull *ndr, int ndr_flags, const char **s)
+{
+ uint32_t offset = ndr->offset;
+ uint32_t max_offset = offset;
+ unsigned num_components;
+ char *name;
+
+ if (!(ndr_flags & NDR_SCALARS)) {
+ return NDR_ERR_SUCCESS;
+ }
+
+ name = NULL;
+
+ /* break up name into a list of components */
+ for (num_components=0;num_components<MAX_COMPONENTS;num_components++) {
+ uint8_t *component = NULL;
+ NDR_CHECK(ndr_pull_component(ndr, &component, &offset, &max_offset));
+ if (component == NULL) break;
+ if (name) {
+ name = talloc_asprintf_append_buffer(name, ".%s", component);
+ NDR_ERR_HAVE_NO_MEMORY(name);
+ } else {
+ name = (char *)component;
+ }
+ }
+ if (num_components == MAX_COMPONENTS) {
+ return ndr_pull_error(ndr, NDR_ERR_STRING,
+ "BAD DNS NAME too many components");
+ }
+ if (num_components == 0) {
+ name = talloc_strdup(ndr, "");
+ NDR_ERR_HAVE_NO_MEMORY(name);
+ }
+
+ (*s) = name;
+ ndr->offset = max_offset;
+
+ return NDR_ERR_SUCCESS;
+}
+
+/**
+ push a dns string to the wire
+*/
+_PUBLIC_ enum ndr_err_code ndr_push_dns_string(struct ndr_push *ndr, int ndr_flags, const char *s)
+{
+ if (!(ndr_flags & NDR_SCALARS)) {
+ return NDR_ERR_SUCCESS;
+ }
+
+ while (s && *s) {
+ enum ndr_err_code ndr_err;
+ char *compname;
+ size_t complen;
+ uint32_t offset;
+
+ /* see if we have pushed the remaing string allready,
+ * if so we use a label pointer to this string
+ */
+ ndr_err = ndr_token_retrieve_cmp_fn(&ndr->dns_string_list, s, &offset, (comparison_fn_t)strcmp, false);
+ if (NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+ uint8_t b[2];
+
+ if (offset > 0x3FFF) {
+ return ndr_push_error(ndr, NDR_ERR_STRING,
+ "offset for dns string label pointer %u[%08X] > 0x00003FFF",
+ offset, offset);
+ }
+
+ b[0] = 0xC0 | (offset>>8);
+ b[1] = (offset & 0xFF);
+
+ return ndr_push_bytes(ndr, b, 2);
+ }
+
+ complen = strcspn(s, ".");
+
+ /* we need to make sure the length fits into 6 bytes */
+ if (complen > 0x3F) {
+ return ndr_push_error(ndr, NDR_ERR_STRING,
+ "component length %u[%08X] > 0x0000003F",
+ (unsigned)complen, (unsigned)complen);
+ }
+
+ compname = talloc_asprintf(ndr, "%c%*.*s",
+ (unsigned char)complen,
+ (unsigned char)complen,
+ (unsigned char)complen, s);
+ NDR_ERR_HAVE_NO_MEMORY(compname);
+
+ /* remember the current componemt + the rest of the string
+ * so it can be reused later
+ */
+ NDR_CHECK(ndr_token_store(ndr, &ndr->dns_string_list, s, ndr->offset));
+
+ /* push just this component into the blob */
+ NDR_CHECK(ndr_push_bytes(ndr, (const uint8_t *)compname, complen+1));
+ talloc_free(compname);
+
+ s += complen;
+ if (*s == '.') s++;
+ }
+
+ /* if we reach the end of the string and have pushed the last component
+ * without using a label pointer, we need to terminate the string
+ */
+ return ndr_push_bytes(ndr, (const uint8_t *)"", 1);
+}
git.samba.org / mat / samba.git / commitdiff