source: branches/samba-3.2.x/source/modules/gpfs.c

/* 
 *  Unix SMB/CIFS implementation.
 *  Provide a connection to GPFS specific features
 *  Copyright (C) Volker Lendecke 2005
 *
 *  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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "includes.h"

#ifdef HAVE_GPFS

#include "gpfs_gpl.h"
#include "vfs_gpfs.h"

static bool gpfs_share_modes;
static bool gpfs_leases;

static int (*gpfs_set_share_fn)(int fd, unsigned int allow, unsigned int deny);
static int (*gpfs_set_lease_fn)(int fd, unsigned int leaseType);
static int (*gpfs_getacl_fn)(char *pathname, int flags, void *acl);
static int (*gpfs_putacl_fn)(char *pathname, int flags, void *acl);


bool set_gpfs_sharemode(files_struct *fsp, uint32 access_mask,
                        uint32 share_access)
{
        unsigned int allow = GPFS_SHARE_NONE;
        unsigned int deny = GPFS_DENY_NONE;
        int result;

        if (!gpfs_share_modes) {
                return True;
        }
        
        if (gpfs_set_share_fn == NULL) {
                return False;
        }

        if ((fsp == NULL) || (fsp->fh == NULL) || (fsp->fh->fd < 0)) {
                /* No real file, don't disturb */
                return True;
        }

        allow |= (access_mask & (FILE_WRITE_DATA|FILE_APPEND_DATA|
                                 DELETE_ACCESS)) ? GPFS_SHARE_WRITE : 0;
        allow |= (access_mask & (FILE_READ_DATA|FILE_EXECUTE)) ?
                GPFS_SHARE_READ : 0;

        if (allow == GPFS_SHARE_NONE) {
                DEBUG(10, ("special case am=no_access:%x\n",access_mask));
        }
        else {  
                deny |= (share_access & FILE_SHARE_WRITE) ?
                        0 : GPFS_DENY_WRITE;
                deny |= (share_access & (FILE_SHARE_READ)) ?
                        0 : GPFS_DENY_READ;
        }
        DEBUG(10, ("am=%x, allow=%d, sa=%x, deny=%d\n",
                   access_mask, allow, share_access, deny));

        result = gpfs_set_share_fn(fsp->fh->fd, allow, deny);
        if (result != 0) {
                if (errno == ENOSYS) {
                        DEBUG(5, ("VFS module vfs_gpfs loaded, but no gpfs "
                                  "support has been compiled into Samba. Allowing access\n"));
                        return True;
                } else {
                        DEBUG(10, ("gpfs_set_share failed: %s\n",
                                   strerror(errno)));
                }
        }

        return (result == 0);
}

int set_gpfs_lease(int fd, int leasetype)
{
        int gpfs_type = GPFS_LEASE_NONE;

        if (!gpfs_leases) {
                return True;
        }

        if (gpfs_set_lease_fn == NULL) {
                errno = EINVAL;
                return -1;
        }

        if (leasetype == F_RDLCK) {
                gpfs_type = GPFS_LEASE_READ;
        }
        if (leasetype == F_WRLCK) {
                gpfs_type = GPFS_LEASE_WRITE;
        }
        
        /* we unconditionally set CAP_LEASE, rather than looking for
           -1/EACCES as there is a bug in some versions of
           libgpfs_gpl.so which results in a leaked fd on /dev/ss0
           each time we try this with the wrong capabilities set
        */
        linux_set_lease_capability();
        return gpfs_set_lease_fn(fd, gpfs_type);
}

int smbd_gpfs_getacl(char *pathname, int flags, void *acl)
{
        if (gpfs_getacl_fn == NULL) {
                errno = ENOSYS;
                return -1;
        }

        return gpfs_getacl_fn(pathname, flags, acl);
}

int smbd_gpfs_putacl(char *pathname, int flags, void *acl)
{
        if (gpfs_putacl_fn == NULL) {
                errno = ENOSYS;
                return -1;
        }

        return gpfs_putacl_fn(pathname, flags, acl);
}

static bool init_gpfs_function_lib(void *plibhandle_pointer,
                                   const char *libname,
                                   void *pfn_pointer, const char *fn_name)
{
        bool did_open_here = false;
        void **libhandle_pointer = (void **)plibhandle_pointer;
        void **fn_pointer = (void **)pfn_pointer;

        if (*libhandle_pointer == NULL) {
                *libhandle_pointer = sys_dlopen(libname, RTLD_LAZY);
                did_open_here = true;
        }
        if (*libhandle_pointer == NULL) {
                DEBUG(10, ("Could not open lib %s\n", libname));
                return false;
        }

        *fn_pointer = sys_dlsym(*libhandle_pointer, fn_name);
        if (*fn_pointer == NULL) {
                DEBUG(10, ("Did not find symbol %s in lib %s\n",
                           fn_name, libname));
                if (did_open_here) {
                        sys_dlclose(*libhandle_pointer);
                        *libhandle_pointer = NULL;
                }
                return false;
        }

        return true;
}

static bool init_gpfs_function(void *fn_pointer, const char *fn_name)
{
        static void *libgpfs_handle = NULL;
        static void *libgpfs_gpl_handle = NULL;

        if (init_gpfs_function_lib(&libgpfs_handle, "libgpfs.so",
                                   fn_pointer, fn_name)) {
                return true;
        }
        if (init_gpfs_function_lib(&libgpfs_gpl_handle, "libgpfs_gpl.so",
                                   fn_pointer, fn_name)) {
                return true;
        }
        return false;
}

void init_gpfs(void)
{
        init_gpfs_function(&gpfs_set_share_fn, "gpfs_set_share");
        init_gpfs_function(&gpfs_set_lease_fn, "gpfs_set_lease");
        init_gpfs_function(&gpfs_getacl_fn, "gpfs_getacl");
        init_gpfs_function(&gpfs_putacl_fn, "gpfs_putacl");

        gpfs_share_modes = lp_parm_bool(-1, "gpfs", "sharemodes", True);
        gpfs_leases      = lp_parm_bool(-1, "gpfs", "leases", True);

        return;
}

#else

int set_gpfs_lease(int snum, int leasetype)
{
        DEBUG(0, ("'VFS module smbgpfs loaded, without gpfs support compiled\n"));

        /* We need to indicate that no GPFS is around by returning ENOSYS, so
         * that the normal linux kernel oplock code is called. */
        errno = ENOSYS;
        return -1;
}

bool set_gpfs_sharemode(files_struct *fsp, uint32 access_mask,
                        uint32 share_access)
{
        DEBUG(0, ("VFS module - smbgpfs.so loaded, without gpfs support compiled\n"));
        /* Don't disturb but complain */
        return True;
}

int smbd_gpfs_getacl(char *pathname, int flags, void *acl)
{
        errno = ENOSYS;
        return -1;
}

int smbd_gpfs_putacl(char *pathname, int flags, void *acl)
{
        errno = ENOSYS;
        return -1;
}

void init_gpfs(void)
{
        return;
}

#endif /* HAVE_GPFS */