export: Add fsidd

The fsidnum daemon offers a local UNIX domain socket interface
for all NFS userspace to query the reexport database.
Currently fsidd just uses the SQlite backend.

fsidd serves also as an example on how to implement more complex
backends for the load balancing use case.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Steve Dickson <steved@redhat.com>

3 files changed, 211 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index 682153d..da666b8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -72,6 +72,7 @@ support/nsm/sm_inter_clnt.c
 support/nsm/sm_inter_svc.c
 support/nsm/sm_inter_xdr.c
 support/include/sm_inter.h
+support/reexport/fsidd
 tests/nsm_client/nlm_sm_inter.h
 tests/nsm_client/nlm_sm_inter_clnt.c
 tests/nsm_client/nlm_sm_inter_svc.c
diff --git a/support/reexport/Makefile.am b/support/reexport/Makefile.am
index 9d544a8..fbd66a2 100644
--- a/support/reexport/Makefile.am
+++ b/support/reexport/Makefile.am
@@ -3,4 +3,16 @@
 noinst_LIBRARIES = libreexport.a
 libreexport_a_SOURCES = reexport.c
 
+sbin_PROGRAMS	= fsidd
+
+fsidd_SOURCES = fsidd.c backend_sqlite.c
+
+fsidd_LDADD = ../../support/misc/libmisc.a \
+	      ../../support/nfs/libnfs.la \
+	       $(LIBPTHREAD) $(LIBEVENT) $(LIBSQLITE) \
+	       $(OPTLIBS)
+
+fsidd_CPPFLAGS = $(AM_CPPFLAGS) $(CPPFLAGS) \
+		  -I$(top_builddir)/support/include
+
 MAINTAINERCLEANFILES = Makefile.in
diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
new file mode 100644
index 0000000..410b3a3
--- /dev/null
+++ b/support/reexport/fsidd.c
@@ -0,0 +1,198 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <assert.h>
+#include <dlfcn.h>
+#include <event2/event.h>
+#include <limits.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/random.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/vfs.h>
+#include <unistd.h>
+
+#include "conffile.h"
+#include "reexport_backend.h"
+#include "xcommon.h"
+#include "xlog.h"
+
+#define FSID_SOCKET_NAME "fsid.sock"
+
+static struct event_base *evbase;
+static struct reexpdb_backend_plugin *dbbackend = &sqlite_plug_ops;
+
+static void client_cb(evutil_socket_t cl, short ev, void *d)
+{
+	struct event *me = d;
+	char buf[PATH_MAX * 2];
+	int n;
+
+	(void)ev;
+
+	n = recv(cl, buf, sizeof(buf) - 1, 0);
+	if (n <= 0) {
+		event_del(me);
+		event_free(me);
+		close(cl);
+		return;
+	}
+
+	buf[n] = '\0';
+
+	if (strncmp(buf, "get_fsidnum ", strlen("get_fsidnum ")) == 0) {
+		char *req_path = buf + strlen("get_fsidnum ");
+		uint32_t fsidnum;
+		char *answer = NULL;
+		bool found;
+
+		assert(req_path < buf + n );
+
+		printf("client asks for %s\n", req_path);
+
+		if (dbbackend->fsidnum_by_path(req_path, &fsidnum, false, &found)) {
+			if (found)
+				assert(asprintf(&answer, "+ %u", fsidnum) != -1);
+			else
+				assert(asprintf(&answer, "+ ") != -1);
+		
+		} else {
+			assert(asprintf(&answer, "- %s", "Command failed") != -1);
+		}
+
+		(void)send(cl, answer, strlen(answer), 0);
+
+		free(answer);
+	} else if (strncmp(buf, "get_or_create_fsidnum ", strlen("get_or_create_fsidnum ")) == 0) {
+		char *req_path = buf + strlen("get_or_create_fsidnum ");
+		uint32_t fsidnum;
+		char *answer = NULL;
+		bool found;
+
+		assert(req_path < buf + n );
+
+
+		if (dbbackend->fsidnum_by_path(req_path, &fsidnum, true, &found)) {
+			if (found) {
+				assert(asprintf(&answer, "+ %u", fsidnum) != -1);
+			} else {
+				assert(asprintf(&answer, "+ ") != -1);
+			}
+		
+		} else {
+			assert(asprintf(&answer, "- %s", "Command failed") != -1);
+		}
+
+		(void)send(cl, answer, strlen(answer), 0);
+
+		free(answer);
+	} else if (strncmp(buf, "get_path ", strlen("get_path ")) == 0) {
+		char *req_fsidnum = buf + strlen("get_path ");
+		char *path = NULL, *answer = NULL, *endp;
+		bool bad_input = true;
+		uint32_t fsidnum;
+		bool found;
+
+		assert(req_fsidnum < buf + n );
+
+		errno = 0;
+		fsidnum = strtoul(req_fsidnum, &endp, 10);
+		if (errno == 0 && *endp == '\0') {
+			bad_input = false;
+		}
+
+		if (bad_input) {
+			assert(asprintf(&answer, "- %s", "Command failed: Bad input") != -1);
+		} else {
+			if (dbbackend->path_by_fsidnum(fsidnum, &path, &found)) {
+				if (found)
+					assert(asprintf(&answer, "+ %s", path) != -1);
+				else
+					assert(asprintf(&answer, "+ ") != -1);
+			} else {
+				assert(asprintf(&answer, "+ ") != -1);
+			}
+		}
+
+		(void)send(cl, answer, strlen(answer), 0);
+
+		free(path);
+		free(answer);
+	} else if (strcmp(buf, "version") == 0) {
+		char answer[] = "+ 1";
+
+		(void)send(cl, answer, strlen(answer), 0);
+	} else {
+		char *answer = NULL;
+
+		assert(asprintf(&answer, "- bad command") != -1);
+		(void)send(cl, answer, strlen(answer), 0);
+
+		free(answer);
+	}
+}
+
+static void srv_cb(evutil_socket_t fd, short ev, void *d)
+{
+	int cl = accept4(fd, NULL, NULL, SOCK_NONBLOCK);
+	struct event *client_ev;
+	
+	(void)ev;
+	(void)d;
+
+	client_ev = event_new(evbase, cl, EV_READ | EV_PERSIST | EV_CLOSED, client_cb, event_self_cbarg());
+	event_add(client_ev, NULL);
+}
+
+int main(void)
+{
+	struct event *srv_ev;
+	struct sockaddr_un addr;
+	char *sock_file;
+	int srv;
+
+	conf_init_file(NFS_CONFFILE);
+
+	if (!dbbackend->initdb()) {
+		return 1;
+	}
+
+	sock_file = conf_get_str_with_def("reexport", "fsidd_socket", FSID_SOCKET_NAME);
+
+	unlink(sock_file);
+
+	memset(&addr, 0, sizeof(struct sockaddr_un));
+	addr.sun_family = AF_UNIX;
+	strncpy(addr.sun_path, sock_file, sizeof(addr.sun_path) - 1);
+
+	srv = socket(AF_UNIX, SOCK_SEQPACKET | SOCK_NONBLOCK, 0);
+	if (srv == -1) {
+		xlog(L_WARNING, "Unable to create AF_UNIX socket for %s: %m\n", sock_file);
+		return 1;
+	}
+
+	if (bind(srv, (const struct sockaddr *)&addr, sizeof(struct sockaddr_un)) == -1) {
+		xlog(L_WARNING, "Unable to bind %s: %m\n", sock_file);
+		return 1;
+	}
+
+	if (listen(srv, 5) == -1) {
+		xlog(L_WARNING, "Unable to listen on %s: %m\n", sock_file);
+		return 1;
+	}
+
+	evbase = event_base_new();
+
+	srv_ev = event_new(evbase, srv, EV_READ | EV_PERSIST, srv_cb, NULL);
+	event_add(srv_ev, NULL);
+
+	event_base_dispatch(evbase);
+
+	dbbackend->destroydb();
+
+	return 0;
+}