r21878: Fix a bug with smbd serving a windows terminal server: If winbind decides smbd

to be idle it might happen that smbd needs to do a winbind operation (for
example sid2name) as non-root. This then fails to get the privileged
pipe. When later on on the same connection another authentication request
comes in, we try to do the CRAP auth via the non-privileged pipe.

This adds a winbindd_priv_request_response() request that kills the existing
winbind pipe connection if it's not privileged.

Volker
(This used to be commit e5741e27c4c22702c9f8b07877641fecc7eef39c)

5 files changed, 49 insertions, 12 deletions

diff --git a/source3/auth/auth_winbind.c b/source3/auth/auth_winbind.c
index fa56757950d..f06f83f4065 100644
--- a/source3/auth/auth_winbind.c
+++ b/source3/auth/auth_winbind.c
@@ -108,7 +108,8 @@ static NTSTATUS check_winbind_security(const struct auth_context *auth_context,
 
 	/* we are contacting the privileged pipe */
 	become_root();
-	result = winbindd_request_response(WINBINDD_PAM_AUTH_CRAP, &request, &response);
+	result = winbindd_priv_request_response(WINBINDD_PAM_AUTH_CRAP,
+						&request, &response);
 	unbecome_root();
 
 	if ( result == NSS_STATUS_UNAVAIL )  {
diff --git a/source3/nsswitch/pam_winbind.c b/source3/nsswitch/pam_winbind.c
index e16f44dff50..66f9a093144 100644
--- a/source3/nsswitch/pam_winbind.c
+++ b/source3/nsswitch/pam_winbind.c
@@ -436,7 +436,7 @@ static int pam_winbind_request(pam_handle_t * pamh, int ctrl,
 	/* Fill in request and send down pipe */
 	init_request(request, req_type);
 	
-	if (write_sock(request, sizeof(*request), 0) == -1) {
+	if (write_sock(request, sizeof(*request), 0, 1) == -1) {
 		_pam_log(pamh, ctrl, LOG_ERR, "pam_winbind_request: write to socket failed!");
 		close_sock();
 		return PAM_SERVICE_ERR;
diff --git a/source3/nsswitch/wb_common.c b/source3/nsswitch/wb_common.c
index 05d2a660e73..fb84373aa63 100644
--- a/source3/nsswitch/wb_common.c
+++ b/source3/nsswitch/wb_common.c
@@ -33,6 +33,7 @@ BOOL winbind_on( void );
 /* Global variables.  These are effectively the client state information */
 
 int winbindd_fd = -1;           /* fd for winbindd socket */
+static int is_privileged = 0;
 
 /* Free a response structure */
 
@@ -287,7 +288,7 @@ static int winbind_named_pipe_sock(const char *dir)
 
 /* Connect to winbindd socket */
 
-static int winbind_open_pipe_sock(int recursing)
+static int winbind_open_pipe_sock(int recursing, int need_priv)
 {
 #ifdef HAVE_UNIXSOCKET
 	static pid_t our_pid;
@@ -300,6 +301,10 @@ static int winbind_open_pipe_sock(int recursing)
 		close_sock();
 		our_pid = getpid();
 	}
+
+	if ((need_priv != 0) && (is_privileged == 0)) {
+		close_sock();
+	}
 	
 	if (winbindd_fd != -1) {
 		return winbindd_fd;
@@ -313,6 +318,8 @@ static int winbind_open_pipe_sock(int recursing)
 		return -1;
 	}
 
+	is_privileged = 0;
+
 	/* version-check the socket */
 
 	request.flags = WBFLAG_RECURSE;
@@ -329,9 +336,14 @@ static int winbind_open_pipe_sock(int recursing)
 		if ((fd = winbind_named_pipe_sock((char *)response.extra_data.data)) != -1) {
 			close(winbindd_fd);
 			winbindd_fd = fd;
+			is_privileged = 1;
 		}
 	}
 
+	if ((need_priv != 0) && (is_privileged == 0)) {
+		return -1;
+	}
+
 	SAFE_FREE(response.extra_data.data);
 
 	return winbindd_fd;
@@ -342,7 +354,7 @@ static int winbind_open_pipe_sock(int recursing)
 
 /* Write data to winbindd socket */
 
-int write_sock(void *buffer, int count, int recursing)
+int write_sock(void *buffer, int count, int recursing, int need_priv)
 {
 	int result, nwritten;
 	
@@ -350,7 +362,7 @@ int write_sock(void *buffer, int count, int recursing)
 	
  restart:
 	
-	if (winbind_open_pipe_sock(recursing) == -1) {
+	if (winbind_open_pipe_sock(recursing, need_priv) == -1) {
 		return -1;
 	}
 	
@@ -536,7 +548,8 @@ BOOL winbind_env_set( void )
  * send simple types of requests 
  */
 
-NSS_STATUS winbindd_send_request(int req_type, struct winbindd_request *request)
+NSS_STATUS winbindd_send_request(int req_type, int need_priv,
+				 struct winbindd_request *request)
 {
 	struct winbindd_request lrequest;
 
@@ -555,12 +568,14 @@ NSS_STATUS winbindd_send_request(int req_type, struct winbindd_request *request)
 
 	init_request(request, req_type);
 	
-	if (write_sock(request, sizeof(*request), request->flags & WBFLAG_RECURSE) == -1) {
+	if (write_sock(request, sizeof(*request),
+		       request->flags & WBFLAG_RECURSE, need_priv) == -1) {
 		return NSS_STATUS_UNAVAIL;
 	}
 
 	if ((request->extra_len != 0) &&
-	    (write_sock(request->extra_data.data, request->extra_len, request->flags & WBFLAG_RECURSE) == -1)) {
+	    (write_sock(request->extra_data.data, request->extra_len,
+			request->flags & WBFLAG_RECURSE, need_priv) == -1)) {
 		return NSS_STATUS_UNAVAIL;
 	}
 	
@@ -610,7 +625,25 @@ NSS_STATUS winbindd_request_response(int req_type,
 	int count = 0;
 
 	while ((status == NSS_STATUS_UNAVAIL) && (count < 10)) {
-		status = winbindd_send_request(req_type, request);
+		status = winbindd_send_request(req_type, 0, request);
+		if (status != NSS_STATUS_SUCCESS) 
+			return(status);
+		status = winbindd_get_response(response);
+		count += 1;
+	}
+
+	return status;
+}
+
+NSS_STATUS winbindd_priv_request_response(int req_type, 
+					  struct winbindd_request *request,
+					  struct winbindd_response *response)
+{
+	NSS_STATUS status = NSS_STATUS_UNAVAIL;
+	int count = 0;
+
+	while ((status == NSS_STATUS_UNAVAIL) && (count < 10)) {
+		status = winbindd_send_request(req_type, 1, request);
 		if (status != NSS_STATUS_SUCCESS) 
 			return(status);
 		status = winbindd_get_response(response);
diff --git a/source3/nsswitch/winbind_client.h b/source3/nsswitch/winbind_client.h
index 1d3d379af00..d80aff37fa1 100644
--- a/source3/nsswitch/winbind_client.h
+++ b/source3/nsswitch/winbind_client.h
@@ -2,13 +2,16 @@
 #include "winbindd_nss.h"
 
 void init_request(struct winbindd_request *req,int rq_type);
-NSS_STATUS winbindd_send_request(int req_type,
+NSS_STATUS winbindd_send_request(int req_type, int need_priv,
 				 struct winbindd_request *request);
 NSS_STATUS winbindd_get_response(struct winbindd_response *response);
 NSS_STATUS winbindd_request_response(int req_type, 
 			    struct winbindd_request *request,
 			    struct winbindd_response *response);
-int write_sock(void *buffer, int count, int recursing);
+NSS_STATUS winbindd_priv_request_response(int req_type, 
+					  struct winbindd_request *request,
+					  struct winbindd_response *response);
+int write_sock(void *buffer, int count, int recursing, int need_priv);
 int read_reply(struct winbindd_response *response);
 void close_sock(void);
 void free_response(struct winbindd_response *response);
diff --git a/source3/nsswitch/winbind_nss_irix.c b/source3/nsswitch/winbind_nss_irix.c
index 2fbf3e0df82..5c6679f0442 100644
--- a/source3/nsswitch/winbind_nss_irix.c
+++ b/source3/nsswitch/winbind_nss_irix.c
@@ -454,7 +454,7 @@ send_next_request(nsd_file_t *rq, struct winbindd_request *request)
 	nsd_logprintf(NSD_LOG_MIN,
 		"send_next_request (winbind) %d, timeout = %d sec\n",
 			rq->f_cmd_data, timeout);
-	status = winbindd_send_request((int)rq->f_cmd_data,request);
+	status = winbindd_send_request((int)rq->f_cmd_data,request,0);
 	SAFE_FREE(request);
 
 	if (status != NSS_STATUS_SUCCESS) {