Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 200 insertions, 0 deletions

diff --git a/source3/smbd/dnsregister.c b/source3/smbd/dnsregister.c
new file mode 100644
index 0000000..df18900
--- /dev/null
+++ b/source3/smbd/dnsregister.c
@@ -0,0 +1,200 @@
+/*
+   Unix SMB/CIFS implementation.
+   DNS-SD registration
+   Copyright (C) Rishi Srivatsavai 2007
+
+   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/>.
+*/
+
+#include <includes.h>
+#include "smbd/smbd.h"
+
+/* Uses DNS service discovery (libdns_sd) to
+ * register the SMB service. SMB service is registered
+ * on ".local" domain via Multicast DNS & any
+ * other unicast DNS domains available.
+ *
+ * Users use the smbclient -B (Browse) option to
+ * browse for advertised SMB services.
+ */
+
+#define DNS_REG_RETRY_INTERVAL (5*60)  /* in seconds */
+
+#ifdef WITH_DNSSD_SUPPORT
+
+#include <dns_sd.h>
+
+struct dns_reg_state {
+	struct tevent_context *event_ctx;
+	uint16_t port;
+	DNSServiceRef srv_ref;
+	struct tevent_timer *te;
+	int fd;
+	struct tevent_fd *fde;
+};
+
+static int dns_reg_state_destructor(struct dns_reg_state *dns_state)
+{
+	if (dns_state->srv_ref != NULL) {
+		/* Close connection to the mDNS daemon */
+		DNSServiceRefDeallocate(dns_state->srv_ref);
+		dns_state->srv_ref = NULL;
+	}
+
+	/* Clear event handler */
+	TALLOC_FREE(dns_state->te);
+	TALLOC_FREE(dns_state->fde);
+	dns_state->fd = -1;
+
+	return 0;
+}
+
+static void dns_register_smbd_retry(struct tevent_context *ctx,
+				    struct tevent_timer *te,
+				    struct timeval now,
+				    void *private_data);
+static void dns_register_smbd_fde_handler(struct tevent_context *ev,
+					  struct tevent_fd *fde,
+					  uint16_t flags,
+					  void *private_data);
+
+static bool dns_register_smbd_schedule(struct dns_reg_state *dns_state,
+				       struct timeval tval)
+{
+	dns_reg_state_destructor(dns_state);
+
+	dns_state->te = tevent_add_timer(dns_state->event_ctx,
+					 dns_state,
+					 tval,
+					 dns_register_smbd_retry,
+					 dns_state);
+	if (!dns_state->te) {
+		return false;
+	}
+
+	return true;
+}
+
+static void dns_register_smbd_retry(struct tevent_context *ctx,
+				    struct tevent_timer *te,
+				    struct timeval now,
+				    void *private_data)
+{
+	struct dns_reg_state *dns_state = talloc_get_type_abort(private_data,
+					  struct dns_reg_state);
+	DNSServiceErrorType err;
+
+	dns_reg_state_destructor(dns_state);
+
+	DEBUG(6, ("registering _smb._tcp service on port %d\n",
+		  dns_state->port));
+
+	/* Register service with DNS. Connects with the mDNS
+	 * daemon running on the local system to perform DNS
+	 * service registration.
+	 */
+	err = DNSServiceRegister(&dns_state->srv_ref, 0 /* flags */,
+			kDNSServiceInterfaceIndexAny,
+			NULL /* service name */,
+			"_smb._tcp" /* service type */,
+			NULL /* domain */,
+			"" /* SRV target host name */,
+			htons(dns_state->port),
+			0 /* TXT record len */,
+			NULL /* TXT record data */,
+			NULL /* callback func */,
+			NULL /* callback context */);
+
+	if (err != kDNSServiceErr_NoError) {
+		/* Failed to register service. Schedule a re-try attempt.
+		 */
+		DEBUG(3, ("unable to register with mDNS (err %d)\n", err));
+		goto retry;
+	}
+
+	dns_state->fd = DNSServiceRefSockFD(dns_state->srv_ref);
+	if (dns_state->fd == -1) {
+		goto retry;
+	}
+
+	dns_state->fde = tevent_add_fd(dns_state->event_ctx,
+				       dns_state,
+				       dns_state->fd,
+				       TEVENT_FD_READ,
+				       dns_register_smbd_fde_handler,
+				       dns_state);
+	if (!dns_state->fde) {
+		goto retry;
+	}
+
+	return;
+ retry:
+	dns_register_smbd_schedule(dns_state,
+		timeval_current_ofs(DNS_REG_RETRY_INTERVAL, 0));
+}
+
+/* Processes reply from mDNS daemon. Returns true if a reply was received */
+static void dns_register_smbd_fde_handler(struct tevent_context *ev,
+					  struct tevent_fd *fde,
+					  uint16_t flags,
+					  void *private_data)
+{
+	struct dns_reg_state *dns_state = talloc_get_type_abort(private_data,
+					  struct dns_reg_state);
+	DNSServiceErrorType err;
+
+	err = DNSServiceProcessResult(dns_state->srv_ref);
+	if (err != kDNSServiceErr_NoError) {
+		DEBUG(3, ("failed to process mDNS result (err %d), re-trying\n",
+			    err));
+		goto retry;
+	}
+
+	talloc_free(dns_state);
+	return;
+
+ retry:
+	dns_register_smbd_schedule(dns_state,
+		timeval_current_ofs(DNS_REG_RETRY_INTERVAL, 0));
+}
+
+bool smbd_setup_mdns_registration(struct tevent_context *ev,
+				  TALLOC_CTX *mem_ctx,
+				  uint16_t port)
+{
+	struct dns_reg_state *dns_state;
+
+	dns_state = talloc_zero(mem_ctx, struct dns_reg_state);
+	if (dns_state == NULL) {
+		return false;
+	}
+	dns_state->event_ctx = ev;
+	dns_state->port = port;
+	dns_state->fd = -1;
+
+	talloc_set_destructor(dns_state, dns_reg_state_destructor);
+
+	return dns_register_smbd_schedule(dns_state, timeval_zero());
+}
+
+#else /* WITH_DNSSD_SUPPORT */
+
+bool smbd_setup_mdns_registration(struct tevent_context *ev,
+				  TALLOC_CTX *mem_ctx,
+				  uint16_t port)
+{
+	return true;
+}
+
+#endif /* WITH_DNSSD_SUPPORT */