mountd: add logging of NFSv4 clients attaching and detaching.

NFSv4 does not have a MOUNT request like NFSv3 does (via the MOUNT
protocol).  So these cannot be logged.
NFSv4 does have SETCLIENTID and EXCHANGE_ID.  These are indirectly
visible though changes in /proc/fs/nfsd/clients.
When a new client attaches, a directory appears.  When the client
detaches, through a timeout (v4.0) or DESTROY_SESSION (v4.1+)
the directory disappears.

This patch adds tracking of these changes using inotify, with log
messages when a client attaches or detaches.

Unfortuantely clients are created in two steps, the second being a
confirmation.  This results in a temporary client appearing and
disappearing.  It is not possible (in Linux 5.10) to detect the
unconfirmed client, so extra attach/detach messages are generated.

This patch also moves some cache* function declarations into a header
file, and makes a few related changes to #includes.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Steve Dickson <steved@redhat.com>

4 files changed, 6 insertions, 7 deletions

diff --git a/utils/exportd/exportd.c b/utils/exportd/exportd.c
index 736ab319..f36f51d2 100644
--- a/utils/exportd/exportd.c
+++ b/utils/exportd/exportd.c
@@ -297,6 +297,7 @@ main(int argc, char **argv)
 
 	/* Open files now to avoid sharing descriptors among forked processes */
 	cache_open();
+	v4clients_init();
 
 	/* Process incoming upcalls */
 	cache_process_loop();
diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
index fce38966..39e85fd5 100644
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -31,6 +31,7 @@
 #include "pseudoflavors.h"
 #include "nfsd_path.h"
 #include "nfslib.h"
+#include "export.h"
 
 extern void my_svc_run(void);
 
@@ -924,6 +925,7 @@ main(int argc, char **argv)
 	nfsd_path_init();
 	/* Open files now to avoid sharing descriptors among forked processes */
 	cache_open();
+	v4clients_init();
 
 	xlog(L_NOTICE, "Version " VERSION " starting");
 	my_svc_run();
diff --git a/utils/mountd/mountd.h b/utils/mountd/mountd.h
index f058f01d..d3077531 100644
--- a/utils/mountd/mountd.h
+++ b/utils/mountd/mountd.h
@@ -60,9 +60,4 @@ bool ipaddr_client_matches(nfs_export *exp, struct addrinfo *ai);
 bool namelist_client_matches(nfs_export *exp, char *dom);
 bool client_matches(nfs_export *exp, char *dom, struct addrinfo *ai);
 
-static inline bool is_ipaddr_client(char *dom)
-{
-	return dom[0] == '$';
-}
-
 #endif /* MOUNTD_H */
diff --git a/utils/mountd/svc_run.c b/utils/mountd/svc_run.c
index 41b96d7f..167b9757 100644
--- a/utils/mountd/svc_run.c
+++ b/utils/mountd/svc_run.c
@@ -56,10 +56,9 @@
 #ifdef HAVE_LIBTIRPC
 #include <rpc/rpc_com.h>
 #endif
+#include "export.h"
 
 void my_svc_run(void);
-void cache_set_fds(fd_set *fdset);
-int cache_process_req(fd_set *readfds);
 
 #if defined(__GLIBC__) && LONG_MAX != INT_MAX
 /* bug in glibc 2.3.6 and earlier, we need
@@ -101,6 +100,7 @@ my_svc_run(void)
 
 		readfds = svc_fdset;
 		cache_set_fds(&readfds);
+		v4clients_set_fds(&readfds);
 
 		selret = select(FD_SETSIZE, &readfds,
 				(void *) 0, (void *) 0, (struct timeval *) 0);
@@ -116,6 +116,7 @@ my_svc_run(void)
 
 		default:
 			selret -= cache_process_req(&readfds);
+			selret -= v4clients_process(&readfds);
 			if (selret)
 				svc_getreqset(&readfds);
 		}