nfsdcld: add client tracking daemon stub

This program opens and "listens" on the new nfsd/cld rpc_pipefs pipe.
The code here doesn't actually do anything on stable storage yet. That
will be added in a later patch.

The patch also adds a autoconf enable switch for the new daemon that
defaults to "no", and a test for the upcall description header file.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

5 files changed, 357 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index 67e8d2d..a9ffb68 100644
--- a/configure.ac
+++ b/configure.ac
@@ -185,6 +185,12 @@ else
 	AM_CONDITIONAL(MOUNT_CONFIG, [test "$enable_mount" = "yes"])
 fi
 
+AC_ARG_ENABLE(nfsdcld,
+	[AC_HELP_STRING([--enable-nfsdcld],
+			[Create nfsdcld NFSv4 clientid tracking daemon. @<:@default=no@:>@])],
+	enable_nfsdcld=$enableval,
+	enable_nfsdcld="no")
+
 dnl Check for TI-RPC library and headers
 AC_LIBTIRPC
 
@@ -260,6 +266,8 @@ if test "$enable_nfsv4" = yes; then
   dnl check for the keyutils libraries and headers
   AC_KEYUTILS
 
+  AM_CONDITIONAL(CONFIG_NFSDCLD, [test "$enable_nfsdcld" = "yes" ])
+
   dnl librpcsecgss already has a dependency on libgssapi,
   dnl but we need to make sure we get the right version
   if test "$enable_gss" = yes; then
@@ -457,6 +465,7 @@ AC_CONFIG_FILES([
 	tools/nfs-iostat/Makefile
 	utils/Makefile
 	utils/blkmapd/Makefile
+	utils/nfsdcld/Makefile
 	utils/exportfs/Makefile
 	utils/gssd/Makefile
 	utils/idmapd/Makefile
diff --git a/support/include/cld.h b/support/include/cld.h
new file mode 100644
index 0000000..f14a9ab
--- /dev/null
+++ b/support/include/cld.h
@@ -0,0 +1,56 @@
+/*
+ * Upcall description for nfsdcld communication
+ *
+ * Copyright (c) 2012 Red Hat, Inc.
+ * Author(s): Jeff Layton <jlayton@redhat.com>
+ *
+ *  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 2 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, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _NFSD_CLD_H
+#define _NFSD_CLD_H
+
+/* latest upcall version available */
+#define CLD_UPCALL_VERSION 1
+
+/* defined by RFC3530 */
+#define NFS4_OPAQUE_LIMIT 1024
+
+enum cld_command {
+	Cld_Create,		/* create a record for this cm_id */
+	Cld_Remove,		/* remove record of this cm_id */
+	Cld_Check,		/* is this cm_id allowed? */
+	Cld_GraceDone,		/* grace period is complete */
+};
+
+/* representation of long-form NFSv4 client ID */
+struct cld_name {
+	uint16_t	cn_len;				/* length of cm_id */
+	unsigned char	cn_id[NFS4_OPAQUE_LIMIT];	/* client-provided */
+} __attribute__((packed));
+
+/* message struct for communication with userspace */
+struct cld_msg {
+	uint8_t		cm_vers;		/* upcall version */
+	uint8_t		cm_cmd;			/* upcall command */
+	int16_t		cm_status;		/* return code */
+	uint32_t	cm_xid;			/* transaction id */
+	union {
+		int64_t		cm_gracetime;	/* grace period start time */
+		struct cld_name	cm_name;
+	} __attribute__((packed)) cm_u;
+} __attribute__((packed));
+
+#endif /* !_NFSD_CLD_H */
diff --git a/utils/Makefile.am b/utils/Makefile.am
index d074b85..5df7ca7 100644
--- a/utils/Makefile.am
+++ b/utils/Makefile.am
@@ -21,6 +21,10 @@ if CONFIG_MOUNT
 OPTDIRS += mount
 endif
 
+if CONFIG_NFSDCLD
+OPTDIRS += nfsdcld
+endif
+
 SUBDIRS = \
 	exportfs \
 	mountd \
diff --git a/utils/nfsdcld/Makefile.am b/utils/nfsdcld/Makefile.am
new file mode 100644
index 0000000..ed7ed42
--- /dev/null
+++ b/utils/nfsdcld/Makefile.am
@@ -0,0 +1,14 @@
+## Process this file with automake to produce Makefile.in
+
+#man8_MANS	= nfsdcld.man
+#EXTRA_DIST = $(man8_MANS)
+
+AM_CFLAGS	+= -D_LARGEFILE64_SOURCE
+sbin_PROGRAMS	= nfsdcld
+
+nfsdcld_SOURCES = nfsdcld.c
+
+nfsdcld_LDADD = ../../support/nfs/libnfs.a $(LIBEVENT)
+
+MAINTAINERCLEANFILES = Makefile.in
+
diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
new file mode 100644
index 0000000..9fab2c3
--- /dev/null
+++ b/utils/nfsdcld/nfsdcld.c
@@ -0,0 +1,274 @@
+/*
+ * nfsdcld.c -- NFSv4 client name tracking daemon
+ *
+ * Copyright (C) 2011  Red Hat, Jeff Layton <jlayton@redhat.com>
+ *
+ * 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 2
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif /* HAVE_CONFIG_H */
+
+#include <errno.h>
+#include <event.h>
+#include <stdbool.h>
+#include <getopt.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "xlog.h"
+#include "nfslib.h"
+#include "cld.h"
+
+#ifndef PIPEFS_DIR
+#define PIPEFS_DIR NFS_STATEDIR "/rpc_pipefs"
+#endif
+
+#define DEFAULT_CLD_PATH	PIPEFS_DIR "/nfsd/cld"
+
+#define UPCALL_VERSION		1
+
+/* private data structures */
+struct cld_client {
+	int			cl_fd;
+	struct event		cl_event;
+	struct cld_msg	cl_msg;
+};
+
+/* global variables */
+static char *pipepath = DEFAULT_CLD_PATH;
+
+static struct option longopts[] =
+{
+	{ "help", 0, NULL, 'h' },
+	{ "foreground", 0, NULL, 'F' },
+	{ "debug", 0, NULL, 'd' },
+	{ "pipe", 1, NULL, 'p' },
+	{ NULL, 0, 0, 0 },
+};
+
+/* forward declarations */
+static void cldcb(int UNUSED(fd), short which, void *data);
+
+static void
+usage(char *progname)
+{
+	printf("Usage: %s [ -hFd ] [ -p pipe ]\n", progname);
+}
+
+static int
+cld_pipe_open(struct cld_client *clnt)
+{
+	int fd;
+
+	xlog(D_GENERAL, "%s: opening upcall pipe %s", __func__, pipepath);
+	fd = open(pipepath, O_RDWR, 0);
+	if (fd < 0) {
+		xlog(L_ERROR, "%s: open of %s failed: %m", __func__, pipepath);
+		return -errno;
+	}
+
+	if (clnt->cl_event.ev_flags & EVLIST_INIT)
+		event_del(&clnt->cl_event);
+	if (clnt->cl_fd >= 0)
+		close(clnt->cl_fd);
+
+	clnt->cl_fd = fd;
+	event_set(&clnt->cl_event, clnt->cl_fd, EV_READ, cldcb, clnt);
+	/* event_add is done by the caller */
+	return 0;
+}
+
+static int
+cld_pipe_init(struct cld_client *clnt)
+{
+	int ret;
+
+	clnt->cl_fd = -1;
+	ret = cld_pipe_open(clnt);
+	if (ret)
+		return ret;
+
+	event_add(&clnt->cl_event, NULL);
+	return 0;
+}
+
+static void
+cld_not_implemented(struct cld_client *clnt)
+{
+	int ret;
+	ssize_t bsize, wsize;
+	struct cld_msg *cmsg = &clnt->cl_msg;
+
+	xlog(D_GENERAL, "%s: downcalling with not implemented error", __func__);
+
+	/* set up reply */
+	cmsg->cm_status = -EOPNOTSUPP;
+
+	bsize = sizeof(*cmsg);
+
+	wsize = atomicio((void *)write, clnt->cl_fd, cmsg, bsize);
+	if (wsize != bsize)
+		xlog(L_ERROR, "%s: problem writing to cld pipe (%ld): %m",
+			 __func__, wsize);
+
+	/* reopen pipe, just to be sure */
+	ret = cld_pipe_open(clnt);
+	if (ret) {
+		xlog(L_FATAL, "%s: unable to reopen pipe: %d", __func__, ret);
+		exit(ret);
+	}
+}
+
+static void
+cld_create(struct cld_client *clnt)
+{
+	int ret;
+	ssize_t bsize, wsize;
+	struct cld_msg *cmsg = &clnt->cl_msg;
+
+	xlog(D_GENERAL, "%s: create client record", __func__);
+
+	/* FIXME: create client record on storage here */
+
+	/* set up reply */
+	cmsg->cm_status = 0;
+
+	bsize = sizeof(*cmsg);
+
+	wsize = atomicio((void *)write, clnt->cl_fd, cmsg, bsize);
+	if (wsize != bsize) {
+		xlog(L_ERROR, "%s: problem writing to cld pipe (%ld): %m",
+			 __func__, wsize);
+		ret = cld_pipe_open(clnt);
+		if (ret) {
+			xlog(L_FATAL, "%s: unable to reopen pipe: %d",
+					__func__, ret);
+			exit(ret);
+		}
+	}
+}
+
+static void
+cldcb(int UNUSED(fd), short which, void *data)
+{
+	ssize_t len;
+	struct cld_client *clnt = data;
+	struct cld_msg *cmsg = &clnt->cl_msg;
+
+	if (which != EV_READ)
+		goto out;
+
+	len = atomicio(read, clnt->cl_fd, cmsg, sizeof(*cmsg));
+	if (len <= 0) {
+		xlog(L_ERROR, "%s: pipe read failed: %m", __func__);
+		cld_pipe_open(clnt);
+		goto out;
+	}
+
+	if (cmsg->cm_vers != UPCALL_VERSION) {
+		xlog(L_ERROR, "%s: unsupported upcall version: %hu",
+				cmsg->cm_vers);
+		cld_pipe_open(clnt);
+		goto out;
+	}
+
+	switch(cmsg->cm_cmd) {
+	case Cld_Create:
+		cld_create(clnt);
+		break;
+	default:
+		xlog(L_WARNING, "%s: command %u is not yet implemented",
+				__func__, cmsg->cm_cmd);
+		cld_not_implemented(clnt);
+	}
+out:
+	event_add(&clnt->cl_event, NULL);
+}
+
+int
+main(int argc, char **argv)
+{
+	char arg;
+	int rc = 0;
+	bool foreground = false;
+	char *progname;
+	struct cld_client clnt;
+
+	memset(&clnt, 0, sizeof(clnt));
+
+	progname = strdup(basename(argv[0]));
+	if (!progname) {
+		fprintf(stderr, "%s: unable to allocate memory.\n", argv[0]);
+		return 1;
+	}
+
+	event_init();
+	xlog_syslog(0);
+	xlog_stderr(1);
+
+	/* process command-line options */
+	while ((arg = getopt_long(argc, argv, "hdFp:", longopts,
+				  NULL)) != EOF) {
+		switch (arg) {
+		case 'd':
+			xlog_config(D_ALL, 1);
+			break;
+		case 'F':
+			foreground = true;
+			break;
+		case 'p':
+			pipepath = optarg;
+			break;
+		default:
+			usage(progname);
+			return 0;
+		}
+	}
+
+
+	xlog_open(progname);
+	if (!foreground) {
+		xlog_syslog(1);
+		xlog_stderr(0);
+		rc = daemon(0, 0);
+		if (rc) {
+			xlog(L_ERROR, "Unable to daemonize: %m");
+			goto out;
+		}
+	}
+
+	/* set up storage db */
+
+	/* set up event handler */
+	rc = cld_pipe_init(&clnt);
+	if (rc)
+		goto out;
+
+	xlog(D_GENERAL, "%s: Starting event dispatch handler.", __func__);
+	rc = event_dispatch();
+	if (rc < 0)
+		xlog(L_ERROR, "%s: event_dispatch failed: %m", __func__);
+
+	close(clnt.cl_fd);
+out:
+	free(progname);
+	return rc;
+}