nfs_Readlink.c

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/*
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 * Copyright CEA/DAM/DIF  (2008)
 * contributeur : Philippe DENIEL   philippe.deniel@cea.fr
 *                Thomas LEIBOVICI  thomas.leibovici@cea.fr
 *
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; 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

#ifdef _SOLARIS
#include "solaris_port.h"
#endif

#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include <fcntl.h>
#include <sys/file.h>           /* for having FNDELAY */
#include "HashData.h"
#include "HashTable.h"
#include "log.h"
#include "ganesha_rpc.h"
#include "nfs23.h"
#include "nfs4.h"
#include "mount.h"
#include "nfs_core.h"
#include "cache_inode.h"
#include "nfs_exports.h"
#include "nfs_creds.h"
#include "nfs_proto_functions.h"
#include "nfs_tools.h"
#include "nfs_proto_tools.h"

int nfs_Readlink(nfs_arg_t *parg,
                 exportlist_t *pexport,
                 fsal_op_context_t *pcontext,
                 nfs_worker_data_t *pworker,
                 struct svc_req *preq,
                 nfs_res_t * pres)
{
  cache_entry_t *pentry = NULL;
  fsal_attrib_list_t attr;
  cache_inode_file_type_t filetype;
  cache_inode_status_t cache_status;
  fsal_path_t symlink_data;
  char *ptr = NULL;
  int rc = NFS_REQ_OK;

  if(isDebug(COMPONENT_NFSPROTO))
    {
      char str[LEN_FH_STR];
      nfs_FhandleToStr(preq->rq_vers,
                       &(parg->arg_readlink2),
                       &(parg->arg_readlink3.symlink),
                       NULL,
                       str);
      LogDebug(COMPONENT_NFSPROTO,
               "REQUEST PROCESSING: Calling nfs_Readlink handle: %s", str);
    }

  if(preq->rq_vers == NFS_V3)
    {
      /* to avoid setting it on each error case */
      pres->res_readlink3.READLINK3res_u.resfail.symlink_attributes.attributes_follow =
          FALSE;
    }
  /* Convert file handle into a vnode */
  if((pentry = nfs_FhandleToCache(preq->rq_vers,
                                  &(parg->arg_readlink2),
                                  &(parg->arg_readlink3.symlink),
                                  NULL,
                                  &(pres->res_readlink2.status),
                                  &(pres->res_readlink3.status),
                                  NULL, &attr, pcontext, &rc)) == NULL)
    {
      /* Stale NFS FH ? */
      goto out;
    }

  /* Extract the filetype */
  filetype = cache_inode_fsal_type_convert(attr.type);

  /* Sanity Check: the pentry must be a link */
  if(filetype != SYMBOLIC_LINK)
    {
      switch (preq->rq_vers)
        {
        case NFS_V2:
          pres->res_readlink2.status = NFSERR_IO;
          break;

        case NFS_V3:
          pres->res_readlink3.status = NFS3ERR_INVAL;
        }                       /* switch */
      rc = NFS_REQ_OK;
      goto out;
    }

  /* if */
  /* Perform readlink on the pentry */
  if(cache_inode_readlink(pentry,
                          &symlink_data,
                          pcontext, &cache_status)
     == CACHE_INODE_SUCCESS)
    {
      if((ptr = gsh_malloc(symlink_data.len+1)) == NULL)
        {
          switch (preq->rq_vers)
            {
            case NFS_V2:
              pres->res_readlink2.status = NFSERR_NXIO;
              break;

            case NFS_V3:
              pres->res_readlink3.status = NFS3ERR_IO;
            }                   /* switch */
          rc = NFS_REQ_OK;
          goto out;
        }

      strcpy(ptr, symlink_data.path);

      /* Reply to the client (think about free data after use ) */
      switch (preq->rq_vers)
        {
        case NFS_V2:
          pres->res_readlink2.READLINK2res_u.data = ptr;
          pres->res_readlink2.status = NFS_OK;
          break;

        case NFS_V3:
          pres->res_readlink3.READLINK3res_u.resok.data = ptr;
          nfs_SetPostOpAttr(pexport,
                            &attr,
                            &(pres->res_readlink3.READLINK3res_u.resok.
                              symlink_attributes));
          pres->res_readlink3.status = NFS3_OK;
          break;
        }
      rc = NFS_REQ_OK;
      goto out;
    }

  /* If we are here, there was an error */
  if(nfs_RetryableError(cache_status))
    {
      rc = NFS_REQ_DROP;
      goto out;
    }

  nfs_SetFailedStatus(pcontext, pexport,
                      preq->rq_vers,
                      cache_status,
                      &pres->res_readlink2.status,
                      &pres->res_readlink3.status,
                      pentry,
                      &(pres->res_readlink3.READLINK3res_u.resfail.symlink_attributes),
                      NULL, NULL, NULL, NULL, NULL, NULL);

  rc = NFS_REQ_OK;

out:
  /* return references */
  if (pentry)
      cache_inode_put(pentry);

  return (rc);
}                               /* nfs_Readlink */

void nfs2_Readlink_Free(nfs_res_t * resp)
{
  if(resp->res_readlink2.status == NFS_OK)
    gsh_free(resp->res_readlink2.READLINK2res_u.data);
}                               /* nfs2_Readlink_Free */

void nfs3_Readlink_Free(nfs_res_t * resp)
{
  if(resp->res_readlink3.status == NFS3_OK)
    gsh_free(resp->res_readlink3.READLINK3res_u.resok.data);
}                               /* nfs3_Readlink_Free */