Add smbclient support for basic mDNS browsing.

Patch from Rishi Srivatsavai (bugzilla #4150), with tallocification
and minor syle changes by me.
(This used to be commit db74b99d0ef1a60894c838b4c9d0d454db6cf620)

2 files changed, 243 insertions, 0 deletions

diff --git a/source3/client/client.c b/source3/client/client.c
index d59af9e6cf..97d7cf0e0b 100644
--- a/source3/client/client.c
+++ b/source3/client/client.c
@@ -28,10 +28,13 @@
 #define REGISTER 0
 #endif
 
+extern int do_smb_browse(void); /* mDNS browsing */
+
 extern bool AllowDebugChange;
 extern bool override_logfile;
 extern char tar_type;
 extern bool in_client;
+
 static int port = 0;
 static char *service;
 static char *desthost;
@@ -4512,6 +4515,7 @@ static int do_message_op(void)
 		{ "send-buffer", 'b', POPT_ARG_INT, &io_bufsize, 'b', "Changes the transmit/send buffer", "BYTES" },
 		{ "port", 'p', POPT_ARG_INT, &port, 'p', "Port to connect to", "PORT" },
 		{ "grepable", 'g', POPT_ARG_NONE, NULL, 'g', "Produce grepable output" },
+                { "browse", 'B', POPT_ARG_NONE, NULL, 'B', "Browse SMB servers using DNS" },
 		POPT_COMMON_SAMBA
 		POPT_COMMON_CONNECTION
 		POPT_COMMON_CREDENTIALS
@@ -4654,6 +4658,9 @@ static int do_message_op(void)
 		case 'g':
 			grepable=true;
 			break;
+		case 'B':
+			return(do_smb_browse());
+
 		}
 	}
 
diff --git a/source3/client/dnsbrowse.c b/source3/client/dnsbrowse.c
new file mode 100644
index 0000000000..c4819cebfa
--- /dev/null
+++ b/source3/client/dnsbrowse.c
@@ -0,0 +1,236 @@
+/*
+   Unix SMB/CIFS implementation.
+   DNS-SD browse client
+   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"
+
+#ifdef WITH_DNSSD_SUPPORT
+
+#include <dns_sd.h>
+
+/* Holds service instances found during DNS browse */
+struct mdns_smbsrv_result
+{
+	char *serviceName;
+	char *regType;
+	char *domain;
+	uint32_t ifIndex;
+	struct mdns_smbsrv_result *nextResult;
+};
+
+/* Maintains state during DNS browse */
+struct mdns_browse_state
+{
+	struct mdns_smbsrv_result *listhead; /* Browse result list head */
+	int browseDone;
+
+};
+
+
+static void
+do_smb_resolve_reply (DNSServiceRef sdRef, DNSServiceFlags flags,
+		uint32_t interfaceIndex, DNSServiceErrorType errorCode,
+		const char *fullname, const char *hosttarget, uint16_t port,
+		uint16_t txtLen, const unsigned char *txtRecord, void *context)
+{
+	printf("SMB service available on %s port %u\n",
+		hosttarget, ntohs(port));
+}
+
+
+static void do_smb_resolve(struct mdns_smbsrv_result *browsesrv)
+{
+	DNSServiceRef mdns_conn_sdref = NULL;
+	int mdnsfd;
+	int fdsetsz;
+	int ret;
+	fd_set *fdset = NULL;
+	struct timeval tv;
+	DNSServiceErrorType err;
+
+	TALLOC_CTX * ctx = talloc_tos();
+
+	err = DNSServiceResolve(&mdns_conn_sdref, 0 /* flags */,
+		browsesrv->ifIndex,
+		browsesrv->serviceName, browsesrv->regType, browsesrv->domain,
+		do_smb_resolve_reply, NULL);
+
+	if (err != kDNSServiceErr_NoError) {
+		return;
+	}
+
+	mdnsfd = DNSServiceRefSockFD(mdns_conn_sdref);
+	for (;;)  {
+		if (fdset != NULL) {
+			TALLOC_FREE(fdset);
+		}
+
+		fdsetsz = howmany(mdnsfd + 1, NFDBITS) * sizeof(fd_mask);
+		fdset = TALLOC_ZERO(ctx, fdsetsz);
+		FD_SET(mdnsfd, fdset);
+
+		tv.tv_sec = 1;
+		tv.tv_usec = 0;
+
+		/* Wait until response received from mDNS daemon */
+		ret = sys_select(mdnsfd + 1, fdset, NULL, NULL, &tv);
+		if (ret <= 0 && errno != EINTR) {
+			break;
+		}
+
+		if (FD_ISSET(mdnsfd, fdset)) {
+			/* Invoke callback function */
+			DNSServiceProcessResult(mdns_conn_sdref);
+			break;
+		}
+	}
+
+	TALLOC_FREE(fdset);
+	DNSServiceRefDeallocate(mdns_conn_sdref);
+}
+
+
+static void
+do_smb_browse_reply(DNSServiceRef sdRef, DNSServiceFlags flags,
+        uint32_t interfaceIndex, DNSServiceErrorType errorCode,
+        const char  *serviceName, const char *regtype,
+        const char  *replyDomain, void  *context)
+{
+	struct mdns_browse_state *bstatep = (struct mdns_browse_state *)context;
+	struct mdns_smbsrv_result *bresult;
+
+	if (bstatep == NULL) {
+		return;
+	}
+
+	if (errorCode != kDNSServiceErr_NoError) {
+		bstatep->browseDone = 1;
+		return;
+	}
+
+	if (flags & kDNSServiceFlagsMoreComing) {
+		bstatep->browseDone = 0;
+	} else {
+		bstatep->browseDone = 1;
+	}
+
+	if (!(flags & kDNSServiceFlagsAdd)) {
+		return;
+	}
+
+	bresult = TALLOC_ARRAY(talloc_tos(), struct mdns_smbsrv_result, 1);
+	if (bresult == NULL) {
+		return;
+	}
+
+	if (bstatep->listhead != NULL) {
+		bresult->nextResult = bstatep->listhead;
+	}
+
+	bresult->serviceName = talloc_strdup(talloc_tos(), serviceName);
+	bresult->regType = talloc_strdup(talloc_tos(), regtype);
+	bresult->domain = talloc_strdup(talloc_tos(), replyDomain);
+	bresult->ifIndex = interfaceIndex;
+	bstatep->listhead = bresult;
+}
+
+int do_smb_browse(void)
+{
+	int mdnsfd;
+	int fdsetsz;
+	int ret;
+	fd_set *fdset = NULL;
+	struct mdns_browse_state bstate;
+	struct mdns_smbsrv_result *resptr;
+	struct timeval tv;
+	DNSServiceRef mdns_conn_sdref = NULL;
+	DNSServiceErrorType err;
+
+	TALLOC_CTX * ctx = talloc_stackframe();
+
+	ZERO_STRUCT(bstate);
+
+	err = DNSServiceBrowse(&mdns_conn_sdref, 0, 0, "_smb._tcp", "",
+			do_smb_browse_reply, &bstate);
+
+	if (err != kDNSServiceErr_NoError) {
+		d_printf("Error connecting to the Multicast DNS daemon\n");
+		TALLOC_FREE(ctx);
+		return 1;
+	}
+
+	mdnsfd = DNSServiceRefSockFD(mdns_conn_sdref);
+	for (;;)  {
+		if (fdset != NULL) {
+			TALLOC_FREE(fdset);
+		}
+
+		fdsetsz = howmany(mdnsfd + 1, NFDBITS) * sizeof(fd_mask);
+		fdset = TALLOC_ZERO(ctx, fdsetsz);
+		FD_SET(mdnsfd, fdset);
+
+		tv.tv_sec = 1;
+		tv.tv_usec = 0;
+
+		/* Wait until response received from mDNS daemon */
+		ret = sys_select(mdnsfd + 1, fdset, NULL, NULL, &tv);
+		if (ret <= 0 && errno != EINTR) {
+			break;
+		}
+
+		if (FD_ISSET(mdnsfd, fdset)) {
+			/* Invoke callback function */
+			if (DNSServiceProcessResult(mdns_conn_sdref)) {
+				break;
+			}
+			if (bstate.browseDone) {
+				break;
+			}
+		}
+	}
+
+	DNSServiceRefDeallocate(mdns_conn_sdref);
+
+	if (bstate.listhead != NULL) {
+		resptr = bstate.listhead;
+		while (resptr != NULL) {
+			struct mdns_smbsrv_result *oldresptr;
+			oldresptr = resptr;
+
+			/* Resolve smb service instance */
+			do_smb_resolve(resptr);
+
+			resptr = resptr->nextResult;
+		}
+	}
+
+	TALLOC_FREE(ctx);
+	return 0;
+}
+
+#else /* WITH_DNSSD_SUPPORT */
+
+int do_smb_browse(void)
+{
+    d_printf("DNS-SD browsing is not supported on this platform\n");
+    return 1;
+}
+
+#endif /* WITH_DNSSD_SUPPORT */
+
+