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-rw-r--r--libcli/dns/dns.h68
-rw-r--r--libcli/dns/dns_hosts_file.c415
2 files changed, 483 insertions, 0 deletions
diff --git a/libcli/dns/dns.h b/libcli/dns/dns.h
new file mode 100644
index 0000000000..01aa6c4e6c
--- /dev/null
+++ b/libcli/dns/dns.h
@@ -0,0 +1,68 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * Internal DNS query structures
+ * Copyright (C) Gerald Carter 2006.
+ * Copyright (C) Andrew Bartlett 2011
+ *
+ * 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/>.
+ */
+
+/* DNS query section in replies */
+
+struct dns_query {
+ const char *hostname;
+ uint16_t type;
+ uint16_t in_class;
+};
+
+/* DNS RR record in reply */
+
+struct dns_rr {
+ const char *hostname;
+ uint16_t type;
+ uint16_t in_class;
+ uint32_t ttl;
+ uint16_t rdatalen;
+ uint8_t *rdata;
+};
+
+/* SRV records */
+
+struct dns_rr_srv {
+ const char *hostname;
+ uint16_t priority;
+ uint16_t weight;
+ uint16_t port;
+ size_t num_ips;
+ struct sockaddr_storage *ss_s; /* support multi-homed hosts */
+};
+
+/* NS records */
+
+struct dns_rr_ns {
+ const char *hostname;
+ struct sockaddr_storage ss;
+};
+
+NTSTATUS resolve_dns_hosts_file_as_sockaddr(const char *dns_hosts_file,
+ const char *name, bool srv_lookup,
+ TALLOC_CTX *mem_ctx,
+ struct sockaddr_storage **return_iplist,
+ int *return_count);
+
+NTSTATUS resolve_dns_hosts_file_as_dns_rr(const char *dns_hosts_file,
+ const char *name, bool srv_lookup,
+ TALLOC_CTX *mem_ctx,
+ struct dns_rr_srv **return_rr,
+ int *return_count);
diff --git a/libcli/dns/dns_hosts_file.c b/libcli/dns/dns_hosts_file.c
new file mode 100644
index 0000000000..94d1d9704a
--- /dev/null
+++ b/libcli/dns/dns_hosts_file.c
@@ -0,0 +1,415 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ read a file containing DNS names, types and IP addresses
+
+ Copyright (C) Andrew Tridgell 1994-1998
+ Copyright (C) Jeremy Allison 2007
+ Copyright (C) Andrew Bartlett 2009-2011
+
+ 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/>.
+*/
+
+/* The purpose of this file is to read the file generated by the samba_dnsupdate script */
+
+#include "includes.h"
+#include "lib/util/xfile.h"
+#include "lib/util/util_net.h"
+#include "system/filesys.h"
+#include "system/network.h"
+#include "libcli/nbt/libnbt.h"
+#include "libcli/dns/dns.h"
+
+#ifdef strcasecmp
+#undef strcasecmp
+#endif
+
+/********************************************************
+ Start parsing the dns_hosts_file file.
+*********************************************************/
+
+static XFILE *startdns_hosts_file(const char *fname)
+{
+ XFILE *fp = x_fopen(fname,O_RDONLY, 0);
+ if (!fp) {
+ DEBUG(4,("startdns_hosts_file: Can't open dns_hosts_file file %s. "
+ "Error was %s\n",
+ fname, strerror(errno)));
+ return NULL;
+ }
+ return fp;
+}
+
+/********************************************************
+ Parse the next line in the dns_hosts_file file.
+*********************************************************/
+
+static bool getdns_hosts_fileent(TALLOC_CTX *ctx, XFILE *fp, char **pp_name, char **pp_name_type,
+ char **pp_next_name,
+ struct sockaddr_storage *pss, uint32_t *p_port)
+{
+ char line[1024];
+
+ *pp_name = NULL;
+ *pp_name_type = NULL;
+ *pp_next_name = NULL;
+ *p_port = 0;
+
+ while(!x_feof(fp) && !x_ferror(fp)) {
+ char *name_type = NULL;
+ char *name = NULL;
+ char *next_name = NULL;
+ char *ip = NULL;
+ char *port = NULL;
+
+ const char *ptr;
+ int count = 0;
+
+ if (!fgets_slash(line,sizeof(line),fp)) {
+ continue;
+ }
+
+ if (*line == '#') {
+ continue;
+ }
+
+ ptr = line;
+
+ if (next_token_talloc(ctx, &ptr, &name_type, NULL))
+ ++count;
+ if (next_token_talloc(ctx, &ptr, &name, NULL))
+ ++count;
+ if (name_type && strcasecmp(name_type, "A") == 0) {
+ if (next_token_talloc(ctx, &ptr, &ip, NULL))
+ ++count;
+ } else if (name_type && strcasecmp(name_type, "SRV") == 0) {
+ if (next_token_talloc(ctx, &ptr, &next_name, NULL))
+ ++count;
+ if (next_token_talloc(ctx, &ptr, &port, NULL))
+ ++count;
+ } else if (name_type && strcasecmp(name_type, "CNAME") == 0) {
+ if (next_token_talloc(ctx, &ptr, &next_name, NULL))
+ ++count;
+ }
+ if (count <= 0)
+ continue;
+
+ if (strcasecmp(name_type, "A") == 0) {
+ if (count != 3) {
+ DEBUG(0,("getdns_hosts_fileent: Ill formed hosts A record [%s]\n",
+ line));
+ continue;
+ }
+ DEBUG(4, ("getdns_hosts_fileent: host entry: %s %s %s\n",
+ name_type, name, ip));
+ if (!interpret_string_addr(pss, ip, AI_NUMERICHOST)) {
+ DEBUG(0,("getdns_hosts_fileent: invalid address "
+ "%s.\n", ip));
+ }
+
+ } else if (strcasecmp(name_type, "SRV") == 0) {
+ if (count != 4) {
+ DEBUG(0,("getdns_hosts_fileent: Ill formed hosts SRV record [%s]\n",
+ line));
+ continue;
+ }
+ *p_port = strtoul(port, NULL, 10);
+ if (*p_port == UINT32_MAX) {
+ DEBUG(0, ("getdns_hosts_fileent: Ill formed hosts SRV record [%s] (invalid port: %s)\n",
+ line, port));
+ continue;
+ }
+ DEBUG(4, ("getdns_hosts_fileent: host entry: %s %s %s %u\n",
+ name_type, name, next_name, (unsigned int)*p_port));
+ *pp_next_name = talloc_strdup(ctx, next_name);
+ if (!*pp_next_name) {
+ return false;
+ }
+ } else if (strcasecmp(name_type, "CNAME") == 0) {
+ if (count != 3) {
+ DEBUG(0,("getdns_hosts_fileent: Ill formed hosts CNAME record [%s]\n",
+ line));
+ continue;
+ }
+ DEBUG(4, ("getdns_hosts_fileent: host entry: %s %s %s\n",
+ name_type, name, next_name));
+ *pp_next_name = talloc_strdup(ctx, next_name);
+ if (!*pp_next_name) {
+ return false;
+ }
+ } else {
+ DEBUG(0,("getdns_hosts_fileent: unknown type %s\n", name_type));
+ continue;
+ }
+
+ *pp_name = talloc_strdup(ctx, name);
+ if (!*pp_name) {
+ return false;
+ }
+
+ *pp_name_type = talloc_strdup(ctx, name_type);
+ if (!*pp_name_type) {
+ return false;
+ }
+ return true;
+ }
+
+ return false;
+}
+
+/********************************************************
+ Finish parsing the dns_hosts_file file.
+*********************************************************/
+
+static void enddns_hosts_file(XFILE *fp)
+{
+ x_fclose(fp);
+}
+
+/********************************************************
+ Resolve via "dns_hosts" method.
+*********************************************************/
+
+static NTSTATUS resolve_dns_hosts_file_as_dns_rr_recurse(const char *dns_hosts_file,
+ const char *name, bool srv_lookup,
+ int level, uint32_t port,
+ TALLOC_CTX *mem_ctx,
+ struct dns_rr_srv **return_rr,
+ int *return_count)
+{
+ /*
+ * "dns_hosts" means parse the local dns_hosts file.
+ */
+
+ XFILE *fp;
+ char *host_name = NULL;
+ char *name_type = NULL;
+ char *next_name = NULL;
+ struct sockaddr_storage return_ss;
+ uint32_t srv_port;
+ NTSTATUS status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
+ TALLOC_CTX *ctx = NULL;
+ TALLOC_CTX *ip_list_ctx = NULL;
+ struct dns_rr_srv *rr = NULL;
+
+ *return_rr = NULL;
+
+ /* Don't recurse forever, even on our own flat files */
+ if (level > 11) {
+ DEBUG(0, ("resolve_dns_hosts_file recursion limit reached looking up %s!\n", name));
+ return status;
+ }
+
+ *return_count = 0;
+
+ DEBUG(3,("resolve_dns_hosts: (%d) "
+ "Attempting %s dns_hosts lookup for name %s\n",
+ level, srv_lookup ? "SRV" : "A", name));
+
+ fp = startdns_hosts_file(dns_hosts_file);
+
+ if ( fp == NULL )
+ return NT_STATUS_OBJECT_NAME_NOT_FOUND;
+
+ ip_list_ctx = talloc_new(mem_ctx);
+ if (!ip_list_ctx) {
+ enddns_hosts_file(fp);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ ctx = talloc_new(ip_list_ctx);
+ if (!ctx) {
+ talloc_free(ip_list_ctx);
+ enddns_hosts_file(fp);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ while (getdns_hosts_fileent(ctx, fp, &host_name, &name_type, &next_name, &return_ss, &srv_port)) {
+ if (!strequal(name, host_name)) {
+ /* continue at the bottom of the loop */
+ } else if (srv_lookup) {
+ if (strcasecmp(name_type, "SRV") == 0) {
+ NTSTATUS status_recurse;
+ struct dns_rr_srv *tmp_rr;
+ int tmp_count = 0;
+ /* we only accept one host name per SRV entry */
+ status_recurse
+ = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, next_name,
+ false,
+ level + 1, srv_port,
+ ip_list_ctx, &tmp_rr,
+ &tmp_count);
+ if (NT_STATUS_EQUAL(status_recurse, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
+ /* Don't fail on a dangling SRV record */
+ } else if (!NT_STATUS_IS_OK(status_recurse)) {
+ enddns_hosts_file(fp);
+ talloc_free(ip_list_ctx);
+ return status_recurse;
+ } else if (tmp_count != 1) {
+ status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
+ } else {
+ status = status_recurse;
+ rr = talloc_realloc(ip_list_ctx, rr, struct dns_rr_srv, (*return_count) + 1);
+ if (!rr) {
+ enddns_hosts_file(fp);
+ return NT_STATUS_NO_MEMORY;
+ }
+ talloc_steal(rr, tmp_rr);
+ rr[*return_count] = *tmp_rr;
+ *return_count = (*return_count) + 1;
+ }
+ }
+ } else if (strcasecmp(name_type, "CNAME") == 0) {
+ /* we only accept one host name per CNAME */
+ enddns_hosts_file(fp);
+ status = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, next_name, false,
+ level + 1, port,
+ mem_ctx, return_rr, return_count);
+ talloc_free(ip_list_ctx);
+ return status;
+ } else if (strcasecmp(name_type, "A") == 0) {
+ if (*return_count == 0) {
+ /* We are happy to keep looking for other possible A record matches */
+ rr = talloc_zero(ip_list_ctx,
+ struct dns_rr_srv);
+
+ if (rr == NULL) {
+ TALLOC_FREE(ctx);
+ enddns_hosts_file(fp);
+ DEBUG(3,("resolve_dns_hosts: talloc_realloc fail !\n"));
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ rr->hostname = talloc_strdup(rr, host_name);
+
+ if (rr->hostname == NULL) {
+ TALLOC_FREE(ctx);
+ enddns_hosts_file(fp);
+ DEBUG(3,("resolve_dns_hosts: talloc_realloc fail !\n"));
+ return NT_STATUS_NO_MEMORY;
+ }
+ rr->port = port;
+
+ *return_count = 1;
+ }
+
+ /* Set the specified port (possibly from a SRV lookup) into the structure we return */
+ set_sockaddr_port((struct sockaddr *)&return_ss, port);
+
+ /* We are happy to keep looking for other possible A record matches */
+ rr->ss_s = talloc_realloc(rr, rr->ss_s,
+ struct sockaddr_storage,
+ rr->num_ips + 1);
+
+ if (rr->ss_s == NULL) {
+ TALLOC_FREE(ctx);
+ enddns_hosts_file(fp);
+ DEBUG(3,("resolve_dns_hosts: talloc_realloc fail !\n"));
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ rr->ss_s[rr->num_ips] = return_ss;
+ rr->num_ips += 1;
+
+ /* we found something */
+ status = NT_STATUS_OK;
+ }
+
+ TALLOC_FREE(ctx);
+ ctx = talloc_new(mem_ctx);
+ if (!ctx) {
+ enddns_hosts_file(fp);
+ return NT_STATUS_NO_MEMORY;
+ }
+ }
+
+ *return_rr = talloc_steal(mem_ctx, rr);
+ TALLOC_FREE(ip_list_ctx);
+ enddns_hosts_file(fp);
+ return status;
+}
+
+/********************************************************
+ Resolve via "dns_hosts_file" method, returning a list of sockaddr_storage values
+*********************************************************/
+
+NTSTATUS resolve_dns_hosts_file_as_sockaddr(const char *dns_hosts_file,
+ const char *name, bool srv_lookup,
+ TALLOC_CTX *mem_ctx,
+ struct sockaddr_storage **return_iplist,
+ int *return_count)
+{
+ NTSTATUS status;
+ struct dns_rr_srv *dns_rr = NULL;
+ int i, j, rr_count = 0;
+
+ *return_iplist = NULL;
+ *return_count = 0;
+
+ status = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, name, srv_lookup,
+ 0, 0,
+ mem_ctx, &dns_rr, &rr_count);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(3,("resolve_dns_hosts (sockaddr): "
+ "failed to obtain %s result records for for name %s: %s\n",
+ srv_lookup ? "SRV" : "A", name, nt_errstr(status)));
+ return status;
+ }
+
+ for (i=0; i < rr_count; i++) {
+ *return_iplist = talloc_realloc(mem_ctx, *return_iplist, struct sockaddr_storage, *return_count + dns_rr[i].num_ips);
+ if (!*return_iplist) {
+ return NT_STATUS_NO_MEMORY;
+ }
+ for (j=0; j < dns_rr[i].num_ips; j++) {
+ (*return_iplist)[*return_count] = dns_rr[i].ss_s[j];
+ *return_count = *return_count + 1;
+ }
+ }
+ DEBUG(3,("resolve_dns_hosts (sockaddr): "
+ "Found %d results for for name %s\n",
+ *return_count, name));
+
+ return NT_STATUS_OK;
+}
+
+/********************************************************
+ Resolve via "dns_hosts_file" method, returning struct dns_rr_srv
+*********************************************************/
+
+NTSTATUS resolve_dns_hosts_file_as_dns_rr(const char *dns_hosts_file,
+ const char *name, bool srv_lookup,
+ TALLOC_CTX *mem_ctx,
+ struct dns_rr_srv **return_rr,
+ int *return_count)
+{
+ NTSTATUS status;
+ *return_rr = NULL;
+ *return_count = 0;
+
+ status = resolve_dns_hosts_file_as_dns_rr_recurse(dns_hosts_file, name, srv_lookup,
+ 0, 0,
+ mem_ctx, return_rr, return_count);
+
+ if (NT_STATUS_IS_OK(status)) {
+ DEBUG(3,("resolve_dns_hosts (dns_rr): "
+ "Found %d %s result records for for name %s\n",
+ *return_count, srv_lookup ? "SRV" : "A", name));
+ } else {
+ DEBUG(3,("resolve_dns_hosts (dns_rr): "
+ "failed to obtain %s result records for for name %s: %s\n",
+ srv_lookup ? "SRV" : "A", name, nt_errstr(status)));
+ }
+ return status;
+}
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