Re: [PATCH v5 1/9] nfsdcld: add client tracking daemon stub

[Steve Dickson <SteveD@redhat.com>]

On 02/01/2012 10:44 AM, Jeff Layton wrote:
> 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>
> ---
>  configure.ac              |   14 +++
>  utils/Makefile.am         |    4 +
>  utils/nfsdcld/Makefile.am |   14 +++
>  utils/nfsdcld/nfsdcld.c   |  275 +++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 307 insertions(+), 0 deletions(-)
>  create mode 100644 utils/nfsdcld/Makefile.am
>  create mode 100644 utils/nfsdcld/nfsdcld.c
> 
> diff --git a/configure.ac b/configure.ac
> index 920e8da..d50e54e 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 +266,13 @@ if test "$enable_nfsv4" = yes; then
>    dnl check for the keyutils libraries and headers
>    AC_KEYUTILS
>  
> +  if test "$enable_nfsdcld" = "yes"; then
> +    AC_CHECK_HEADERS([linux/nfsd/cld.h], ,
> +		     AC_MSG_ERROR([Cannot find header needed for nfsdcld]))
> +  fi
This adds a dependency on the kernel headers being present which 
is unprecedented for nfs-utils or any other package I'm aware of
and I just don't think its a good idea... 

So I'm wondering if there is someway around creating this
dependency...

steved.


> +
> +  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
> @@ -460,6 +473,7 @@ 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/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..7a83fbe
> --- /dev/null
> +++ b/utils/nfsdcld/nfsdcld.c
> @@ -0,0 +1,275 @@
> +/*
> + * 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 <linux/nfsd/cld.h>
> +
> +#include "xlog.h"
> +#include "nfslib.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:\n");
> +	printf("%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;
> +}