libshare_zfs.c revision 57b448de658d89a2c88a001d58073c46ed2180f3
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <libzfs.h>
#include <string.h>
#include <libshare.h>
#include "libshare_impl.h"
#include <libintl.h>
extern sa_share_t _sa_add_share(sa_group_t, char *, int, int *);
extern sa_group_t _sa_create_zfs_group(sa_group_t, char *);
extern char *sa_fstype(char *);
extern void set_node_attr(void *, char *, char *);
extern int sa_is_share(void *);
/*
* File system specific code for ZFS. The original code was stolen
* from the "zfs" command and modified to better suit this library's
* usage.
*/
typedef struct get_all_cbdata {
zfs_handle_t **cb_handles;
size_t cb_alloc;
size_t cb_used;
} get_all_cbdata_t;
/*
* sa_zfs_init(impl_handle)
*
* Initialize an access handle into libzfs. The handle needs to stay
* around until sa_zfs_fini() in order to maintain the cache of
* mounts.
*/
int
sa_zfs_init(sa_handle_impl_t impl_handle)
{
impl_handle->zfs_libhandle = libzfs_init();
if (impl_handle->zfs_libhandle != NULL) {
libzfs_print_on_error(impl_handle->zfs_libhandle, B_TRUE);
return (B_TRUE);
}
return (B_FALSE);
}
/*
* sa_zfs_fini(impl_handle)
*
* cleanup data structures and the libzfs handle used for accessing
* zfs file share info.
*/
void
sa_zfs_fini(sa_handle_impl_t impl_handle)
{
if (impl_handle->zfs_libhandle != NULL) {
libzfs_fini(impl_handle->zfs_libhandle);
impl_handle->zfs_libhandle = NULL;
if (impl_handle->zfs_list != NULL) {
/*
* contents of zfs_list were already freed by
* the call to libzfs_fini().
*/
free(impl_handle->zfs_list);
impl_handle->zfs_list = NULL;
impl_handle->zfs_list_count = 0;
}
}
}
/*
* get_one_filesystem(zfs_handle_t, data)
*
* an interator function called while iterating through the ZFS
* root. It accumulates into an array of file system handles that can
* be used to derive info about those file systems.
*/
static int
get_one_filesystem(zfs_handle_t *zhp, void *data)
{
get_all_cbdata_t *cbp = data;
/*
* Skip any zvols
*/
if (zfs_get_type(zhp) != ZFS_TYPE_FILESYSTEM) {
zfs_close(zhp);
return (0);
}
if (cbp->cb_alloc == cbp->cb_used) {
zfs_handle_t **handles;
if (cbp->cb_alloc == 0)
cbp->cb_alloc = 64;
else
cbp->cb_alloc *= 2;
handles = calloc(1, cbp->cb_alloc * sizeof (void *));
if (handles == NULL) {
return (0);
}
if (cbp->cb_handles) {
(void) memcpy(handles, cbp->cb_handles,
cbp->cb_used * sizeof (void *));
free(cbp->cb_handles);
}
cbp->cb_handles = handles;
}
cbp->cb_handles[cbp->cb_used++] = zhp;
return (zfs_iter_filesystems(zhp, get_one_filesystem, data));
}
/*
* get_all_filesystems(zfs_handle_t ***fslist, size_t *count)
*
* iterate through all ZFS file systems starting at the root. Returns
* a count and an array of handle pointers. Allocating is only done
* once. The caller does not need to free since it will be done at
* sa_zfs_fini() time.
*/
static void
get_all_filesystems(sa_handle_impl_t impl_handle,
zfs_handle_t ***fslist, size_t *count)
{
get_all_cbdata_t cb = { 0 };
if (impl_handle->zfs_list != NULL) {
*fslist = impl_handle->zfs_list;
*count = impl_handle->zfs_list_count;
return;
}
(void) zfs_iter_root(impl_handle->zfs_libhandle,
get_one_filesystem, &cb);
impl_handle->zfs_list = *fslist = cb.cb_handles;
impl_handle->zfs_list_count = *count = cb.cb_used;
}
/*
* mountpoint_compare(a, b)
*
* compares the mountpoint on two zfs file systems handles.
* returns values following strcmp() model.
*/
static int
mountpoint_compare(const void *a, const void *b)
{
zfs_handle_t **za = (zfs_handle_t **)a;
zfs_handle_t **zb = (zfs_handle_t **)b;
char mounta[MAXPATHLEN];
char mountb[MAXPATHLEN];
verify(zfs_prop_get(*za, ZFS_PROP_MOUNTPOINT, mounta,
sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0);
verify(zfs_prop_get(*zb, ZFS_PROP_MOUNTPOINT, mountb,
sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0);
return (strcmp(mounta, mountb));
}
/*
* get_zfs_dataset(impl_handle, path)
*
* get the name of the ZFS dataset the path is equivalent to. The
* dataset name is used for get/set of ZFS properties since libzfs
* requires a dataset to do a zfs_open().
*/
static char *
get_zfs_dataset(sa_handle_impl_t impl_handle, char *path)
{
size_t i, count = 0;
char *dataset = NULL;
zfs_handle_t **zlist;
char mountpoint[ZFS_MAXPROPLEN];
char canmount[ZFS_MAXPROPLEN];
get_all_filesystems(impl_handle, &zlist, &count);
qsort(zlist, count, sizeof (void *), mountpoint_compare);
for (i = 0; i < count; i++) {
/* must have a mountpoint */
if (zfs_prop_get(zlist[i], ZFS_PROP_MOUNTPOINT, mountpoint,
sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
/* no mountpoint */
continue;
}
/* mountpoint must be a path */
if (strcmp(mountpoint, ZFS_MOUNTPOINT_NONE) == 0 ||
strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) == 0)
continue;
/* canmount must be set */
canmount[0] = '\0';
if (!zfs_prop_get(zlist[i], ZFS_PROP_CANMOUNT, canmount,
sizeof (canmount), NULL, NULL, 0, B_FALSE) != 0 ||
strcmp(canmount, "off") == 0)
continue;
/*
* have a mountable handle but want to skip those marked none
* and legacy
*/
if (strcmp(mountpoint, path) == 0) {
dataset = (char *)zfs_get_name(zlist[i]);
break;
}
}
if (dataset != NULL)
dataset = strdup(dataset);
return (dataset);
}
/*
* get_zfs_property(dataset, property)
*
* Get the file system property specified from the ZFS dataset.
*/
static char *
get_zfs_property(char *dataset, zfs_prop_t property)
{
zfs_handle_t *handle = NULL;
char shareopts[ZFS_MAXPROPLEN];
libzfs_handle_t *libhandle;
libhandle = libzfs_init();
if (libhandle != NULL) {
handle = zfs_open(libhandle, dataset, ZFS_TYPE_FILESYSTEM);
if (handle != NULL) {
if (zfs_prop_get(handle, property, shareopts,
sizeof (shareopts), NULL, NULL, 0,
B_FALSE) == 0) {
zfs_close(handle);
libzfs_fini(libhandle);
return (strdup(shareopts));
}
zfs_close(handle);
}
libzfs_fini(libhandle);
}
return (NULL);
}
/*
* sa_zfs_is_shared(handle, path)
*
* Check to see if the ZFS path provided has the sharenfs option set
* or not.
*/
int
sa_zfs_is_shared(sa_handle_t sahandle, char *path)
{
int ret = 0;
char *dataset;
zfs_handle_t *handle = NULL;
char shareopts[ZFS_MAXPROPLEN];
libzfs_handle_t *libhandle;
dataset = get_zfs_dataset((sa_handle_t)sahandle, path);
if (dataset != NULL) {
libhandle = libzfs_init();
if (libhandle != NULL) {
handle = zfs_open(libhandle, dataset,
ZFS_TYPE_FILESYSTEM);
if (handle != NULL) {
if (zfs_prop_get(handle, ZFS_PROP_SHARENFS,
shareopts, sizeof (shareopts), NULL, NULL,
0, B_FALSE) == 0 &&
strcmp(shareopts, "off") != 0) {
ret = 1; /* it is shared */
}
zfs_close(handle);
}
libzfs_fini(libhandle);
}
free(dataset);
}
return (ret);
}
/*
* find_or_create_group(groupname, proto, *err)
*
* While walking the ZFS tree, we need to add shares to a defined
* group. If the group doesn't exist, create it first, making sure it
* is marked as a ZFS group.
*
* Note that all ZFS shares are in a subgroup of the top level group
* called "zfs".
*/
static sa_group_t
find_or_create_group(sa_handle_t handle, char *groupname, char *proto, int *err)
{
sa_group_t group;
sa_optionset_t optionset;
int ret = SA_OK;
/*
* we check to see if the "zfs" group exists. Since this
* should be the top level group, we don't want the
* parent. This is to make sure the zfs group has been created
* and to created if it hasn't been.
*/
group = sa_get_group(handle, groupname);
if (group == NULL) {
group = sa_create_group(handle, groupname, &ret);
/* make sure this is flagged as a ZFS group */
if (group != NULL)
ret = sa_set_group_attr(group, "zfs", "true");
}
if (group != NULL) {
if (proto != NULL) {
optionset = sa_get_optionset(group, proto);
if (optionset == NULL) {
optionset = sa_create_optionset(group, proto);
} else {
char **protolist;
int numprotos, i;
numprotos = sa_get_protocols(&protolist);
for (i = 0; i < numprotos; i++) {
optionset = sa_create_optionset(group,
protolist[i]);
}
if (protolist != NULL)
free(protolist);
}
}
}
if (err != NULL)
*err = ret;
return (group);
}
/*
* find_or_create_zfs_subgroup(groupname, optstring, *err)
*
* ZFS shares will be in a subgroup of the "zfs" master group. This
* function looks to see if the groupname exists and returns it if it
* does or else creates a new one with the specified name and returns
* that. The "zfs" group will exist before we get here, but we make
* sure just in case.
*
* err must be a valid pointer.
*/
static sa_group_t
find_or_create_zfs_subgroup(sa_handle_t handle, char *groupname,
char *optstring, int *err)
{
sa_group_t group = NULL;
sa_group_t zfs;
char *name;
char *options;
/* start with the top-level "zfs" group */
zfs = sa_get_group(handle, "zfs");
*err = SA_OK;
if (zfs != NULL) {
for (group = sa_get_sub_group(zfs); group != NULL;
group = sa_get_next_group(group)) {
name = sa_get_group_attr(group, "name");
if (name != NULL && strcmp(name, groupname) == 0) {
/* have the group so break out of here */
sa_free_attr_string(name);
break;
}
if (name != NULL)
sa_free_attr_string(name);
}
if (group == NULL) {
/*
* need to create the sub-group since it doesn't exist
*/
group = _sa_create_zfs_group(zfs, groupname);
if (group != NULL)
set_node_attr(group, "zfs", "true");
if (strcmp(optstring, "on") == 0)
optstring = "rw";
if (group != NULL) {
options = strdup(optstring);
if (options != NULL) {
*err = sa_parse_legacy_options(group,
options, "nfs");
free(options);
} else {
*err = SA_NO_MEMORY;
}
}
}
}
return (group);
}
/*
* zfs_inherited(handle, source, sourcestr)
*
* handle case of inherited sharenfs. Pulled out of sa_get_zfs_shares
* for readability.
*/
static int
zfs_inherited(sa_handle_t handle, sa_share_t share, char *sourcestr,
char *shareopts, char *mountpoint)
{
int doshopt = 0;
int err = SA_OK;
sa_group_t group;
/*
* Need to find the "real" parent sub-group. It may not be
* mounted, but it was identified in the "sourcestr"
* variable. The real parent not mounted can occur if
* "canmount=off and sharenfs=on".
*/
group = find_or_create_zfs_subgroup(handle, sourcestr, shareopts,
&doshopt);
if (group != NULL) {
share = _sa_add_share(group, mountpoint, SA_SHARE_TRANSIENT,
&err);
/*
* some options may only be on shares. If the opt
* string contains one of those, we put it just on the
* share.
*/
if (share != NULL && doshopt == SA_PROP_SHARE_ONLY) {
char *options;
options = strdup(shareopts);
if (options != NULL) {
err = sa_parse_legacy_options(share, options,
"nfs");
free(options);
}
}
} else {
err = SA_NO_MEMORY;
}
return (err);
}
/*
* zfs_notinherited()
*
* handle case where this is the top of a sub-group in ZFS. Pulled out
* of sa_get_zfs_shares for readability.
*/
static int
zfs_notinherited(sa_group_t group, char *mountpoint, char *shareopts)
{
int err = SA_OK;
sa_share_t share;
set_node_attr(group, "zfs", "true");
share = _sa_add_share(group, mountpoint, SA_SHARE_TRANSIENT, &err);
if (err == SA_OK) {
if (strcmp(shareopts, "on") != 0) {
char *options;
options = strdup(shareopts);
if (options != NULL) {
err = sa_parse_legacy_options(group, options,
"nfs");
free(options);
}
if (err == SA_PROP_SHARE_ONLY) {
/*
* Same as above, some properties may
* only be on shares, but due to the
* ZFS sub-groups being artificial, we
* sometimes get this and have to deal
* with it. We do it by attempting to
* put it on the share.
*/
options = strdup(shareopts);
if (options != NULL)
err = sa_parse_legacy_options(share,
options, "nfs");
if (options != NULL)
free(options);
}
/* unmark the share's changed state */
set_node_attr(share, "changed", NULL);
}
}
return (err);
}
/*
* zfs_grp_error(err)
*
* Print group create error, but only once. If err is 0 do the
* print else don't.
*/
static void
zfs_grp_error(int err)
{
if (err == 0) {
/* only print error once */
(void) fprintf(stderr, dgettext(TEXT_DOMAIN,
"Cannot create ZFS subgroup during initialization:"
" %s\n"), sa_errorstr(SA_SYSTEM_ERR));
}
}
/*
* sa_get_zfs_shares(handle, groupname)
*
* Walk the mnttab for all zfs mounts and determine which are
* shared. Find or create the appropriate group/sub-group to contain
* the shares.
*
* All shares are in a sub-group that will hold the properties. This
* allows representing the inherited property model.
*/
int
sa_get_zfs_shares(sa_handle_t handle, char *groupname)
{
sa_group_t group;
sa_group_t zfsgroup;
int legacy = 0;
int err;
zfs_handle_t **zlist;
char shareopts[ZFS_MAXPROPLEN];
sa_share_t share;
zfs_source_t source;
char sourcestr[ZFS_MAXPROPLEN];
char mountpoint[ZFS_MAXPROPLEN];
size_t count = 0, i;
libzfs_handle_t *zfs_libhandle;
/*
* If we can't access libzfs, don't bother doing anything.
*/
zfs_libhandle = ((sa_handle_impl_t)handle)->zfs_libhandle;
if (zfs_libhandle == NULL)
return (SA_SYSTEM_ERR);
zfsgroup = find_or_create_group(handle, groupname, "nfs", &err);
if (zfsgroup != NULL) {
/*
* need to walk the mounted ZFS pools and datasets to
* find shares that are possible.
*/
get_all_filesystems((sa_handle_impl_t)handle, &zlist, &count);
qsort(zlist, count, sizeof (void *), mountpoint_compare);
group = zfsgroup;
for (i = 0; i < count; i++) {
char *dataset;
source = ZFS_SRC_ALL;
if (zfs_prop_get(zlist[i], ZFS_PROP_MOUNTPOINT,
mountpoint, sizeof (mountpoint), NULL, NULL, 0,
B_FALSE) != 0) {
/* no mountpoint */
continue;
}
/*
* zfs_get_name value must not be freed. It is just a
* pointer to a value in the handle.
*/
if ((dataset = (char *)zfs_get_name(zlist[i])) == NULL)
continue;
/*
* only deal with "mounted" file systems since
* unmounted file systems can't actually be shared.
*/
if (!zfs_is_mounted(zlist[i], NULL))
continue;
if (zfs_prop_get(zlist[i], ZFS_PROP_SHARENFS, shareopts,
sizeof (shareopts), &source, sourcestr,
ZFS_MAXPROPLEN, B_FALSE) == 0 &&
strcmp(shareopts, "off") != 0) {
/* it is shared so add to list */
share = sa_find_share(handle, mountpoint);
err = SA_OK;
if (share != NULL) {
/*
* A zfs file system had been shared
* through traditional methods
* (share/dfstab or added to a non-zfs
* group. Now it has been added to a
* ZFS group via the zfs
* command. Remove from previous
* config and setup with current
* options.
*/
err = sa_remove_share(share);
share = NULL;
}
if (err == SA_OK) {
if (source & ZFS_SRC_INHERITED) {
err = zfs_inherited(handle,
share, sourcestr,
shareopts, mountpoint);
} else {
group = _sa_create_zfs_group(
zfsgroup, dataset);
if (group == NULL) {
static int err = 0;
/*
* there is a problem,
* but we can't do
* anything about it
* at this point so we
* issue a warning an
* move on.
*/
zfs_grp_error(err);
err = 1;
continue;
}
set_node_attr(group, "zfs",
"true");
share = _sa_add_share(group,
mountpoint,
SA_SHARE_TRANSIENT, &err);
err = zfs_notinherited(group,
mountpoint, shareopts);
}
}
}
}
}
/*
* Don't need to free the "zlist" variable since it is only a
* pointer to a cached value that will be freed when
* sa_fini() is called.
*/
return (legacy);
}
#define COMMAND "/usr/sbin/zfs"
/*
* sa_zfs_set_sharenfs(group, path, on)
*
* Update the "sharenfs" property on the path. If on is true, then set
* to the properties on the group or "on" if no properties are
* defined. Set to "off" if on is false.
*/
int
sa_zfs_set_sharenfs(sa_group_t group, char *path, int on)
{
int ret = SA_NOT_IMPLEMENTED;
char *command;
command = malloc(ZFS_MAXPROPLEN * 2);
if (command != NULL) {
char *opts = NULL;
char *dataset = NULL;
FILE *pfile;
sa_handle_impl_t impl_handle;
/* for now, NFS is always available for "zfs" */
if (on) {
opts = sa_proto_legacy_format("nfs", group, 1);
if (opts != NULL && strlen(opts) == 0) {
free(opts);
opts = strdup("on");
}
}
impl_handle = (sa_handle_impl_t)sa_find_group_handle(group);
assert(impl_handle != NULL);
if (impl_handle != NULL)
dataset = get_zfs_dataset(impl_handle, path);
else
ret = SA_SYSTEM_ERR;
if (dataset != NULL) {
(void) snprintf(command, ZFS_MAXPROPLEN * 2,
"%s set sharenfs=\"%s\" %s", COMMAND,
opts != NULL ? opts : "off", dataset);
pfile = popen(command, "r");
if (pfile != NULL) {
ret = pclose(pfile);
if (ret != 0)
ret = SA_SYSTEM_ERR;
}
}
if (opts != NULL)
free(opts);
if (dataset != NULL)
free(dataset);
free(command);
}
return (ret);
}
/*
* sa_zfs_update(group)
*
* call back to ZFS to update the share if necessary.
* Don't do it if it isn't a real change.
*/
int
sa_zfs_update(sa_group_t group)
{
sa_optionset_t protopt;
sa_group_t parent;
char *command;
char *optstring;
int ret = SA_OK;
int doupdate = 0;
FILE *pfile;
if (sa_is_share(group))
parent = sa_get_parent_group(group);
else
parent = group;
if (parent != NULL) {
command = malloc(ZFS_MAXPROPLEN * 2);
if (command == NULL)
return (SA_NO_MEMORY);
*command = '\0';
for (protopt = sa_get_optionset(parent, NULL); protopt != NULL;
protopt = sa_get_next_optionset(protopt)) {
char *proto = sa_get_optionset_attr(protopt, "type");
char *path;
char *dataset = NULL;
char *zfsopts = NULL;
if (sa_is_share(group)) {
path = sa_get_share_attr((sa_share_t)group,
"path");
if (path != NULL) {
sa_handle_impl_t impl_handle;
impl_handle = sa_find_group_handle(
group);
if (impl_handle != NULL)
dataset = get_zfs_dataset(
impl_handle, path);
else
ret = SA_SYSTEM_ERR;
sa_free_attr_string(path);
}
} else {
dataset = sa_get_group_attr(group, "name");
}
/* update only when there is an optstring found */
doupdate = 0;
if (proto != NULL && dataset != NULL) {
optstring = sa_proto_legacy_format(proto,
group, 1);
zfsopts = get_zfs_property(dataset,
ZFS_PROP_SHARENFS);
if (optstring != NULL && zfsopts != NULL) {
if (strcmp(optstring, zfsopts) != 0)
doupdate++;
}
if (doupdate) {
if (optstring != NULL &&
strlen(optstring) > 0) {
(void) snprintf(command,
ZFS_MAXPROPLEN * 2,
"%s set sharenfs=%s %s"
COMMAND,
optstring, dataset);
} else {
(void) snprintf(command,
ZFS_MAXPROPLEN * 2,
"%s set sharenfs=on %s",
COMMAND,
dataset);
}
pfile = popen(command, "r");
if (pfile != NULL)
ret = pclose(pfile);
switch (ret) {
default:
case 1:
ret = SA_SYSTEM_ERR;
break;
case 2:
ret = SA_SYNTAX_ERR;
break;
case 0:
break;
}
}
if (optstring != NULL)
free(optstring);
if (zfsopts != NULL)
free(zfsopts);
}
if (proto != NULL)
sa_free_attr_string(proto);
if (dataset != NULL)
free(dataset);
}
free(command);
}
return (ret);
}
/*
* sa_group_is_zfs(group)
*
* Given the group, determine if the zfs attribute is set.
*/
int
sa_group_is_zfs(sa_group_t group)
{
char *zfs;
int ret = 0;
zfs = sa_get_group_attr(group, "zfs");
if (zfs != NULL) {
ret = 1;
sa_free_attr_string(zfs);
}
return (ret);
}
/*
* sa_path_is_zfs(path)
*
* Check to see if the file system path represents is of type "zfs".
*/
int
sa_path_is_zfs(char *path)
{
char *fstype;
int ret = 0;
fstype = sa_fstype(path);
if (fstype != NULL && strcmp(fstype, "zfs") == 0)
ret = 1;
if (fstype != NULL)
sa_free_fstype(fstype);
return (ret);
}