/*
   networks.c - NSS lookup functions for networks database

   Copyright (C) 2006 West Consulting
   Copyright (C) 2006, 2007, 2008, 2010, 2011, 2012, 2013 Arthur de Jong
   Copyright (C) 2010 Symas Corporation

   This library 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 2.1 of the License, or (at your option) any later version.

   This library 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
*/

#include "config.h"

#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "prototypes.h"
#include "common.h"
#include "compat/attrs.h"

/* Redefine some ERROR_OUT macros as we also want to set h_errnop. */

#undef ERROR_OUT_OPENERROR
#define ERROR_OUT_OPENERROR                                                 \
  *errnop = ENOENT;                                                         \
  *h_errnop = HOST_NOT_FOUND;                                               \
  return (errno == EAGAIN) ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;

#undef ERROR_OUT_READERROR
#define ERROR_OUT_READERROR(fp)                                             \
  (void)tio_close(fp);                                                      \
  fp = NULL;                                                                \
  *errnop = ENOENT;                                                         \
  *h_errnop = NO_RECOVERY;                                                  \
  return NSS_STATUS_UNAVAIL;

#undef ERROR_OUT_BUFERROR
#define ERROR_OUT_BUFERROR(fp)                                              \
  (void)tio_close(fp);                                                      \
  fp = NULL;                                                                \
  *errnop = ERANGE;                                                         \
  *h_errnop = TRY_AGAIN;                                                    \
  return NSS_STATUS_TRYAGAIN;

#undef ERROR_OUT_WRITEERROR
#define ERROR_OUT_WRITEERROR(fp)                                            \
  ERROR_OUT_READERROR(fp)

/* read a single network entry from the stream, ignoring entries
   that are not AF_INET (IPv4), result is stored in result */
static nss_status_t read_netent(TFILE *fp, struct netent *result,
                                char *buffer, size_t buflen, int *errnop,
                                int *h_errnop)
{
  int32_t tmpint32, tmp2int32, tmp3int32;
  int32_t numaddr;
  int readaf;
  size_t bufptr = 0;
  nss_status_t retv = NSS_STATUS_NOTFOUND;
  memset(result, 0, sizeof(struct netent));
  /* read the network entry */
  READ_BUF_STRING(fp, result->n_name);
  READ_BUF_STRINGLIST(fp, result->n_aliases);
  result->n_addrtype = AF_INET;
  /* read number of addresses to follow */
  READ_INT32(fp, numaddr);
  /* go through the address list and filter on af */
  while (--numaddr >= 0)
  {
    /* read address family and size */
    READ_INT32(fp, readaf);
    READ_INT32(fp, tmp2int32); /* address length */
    if ((readaf == AF_INET) && (tmp2int32 == 4))
    {
      /* read address and translate to host byte order */
      READ_INT32(fp, result->n_net);
      /* signal that we've read a proper entry */
      retv = NSS_STATUS_SUCCESS;
      /* don't return here to not upset the stream */
    }
    else
    {
      /* skip unsupported address families */
      SKIP(fp, tmpint32);
    }
  }
  return retv;
}

/* write an address value */
/* version 2.10 of glibc changed the address from network to host order
   (changelog entry 2009-07-01) */
#define WRITE_ADDRESS(fp, addr)                                             \
  WRITE_INT32(fp, AF_INET);                                                 \
  WRITE_INT32(fp, 4);                                                       \
  WRITE_INT32(fp, addr);

#ifdef NSS_FLAVOUR_GLIBC

/* get a network entry by name */
nss_status_t _nss_ldap_getnetbyname_r(const char *name,
                                      struct netent *result, char *buffer,
                                      size_t buflen, int *errnop,
                                      int *h_errnop)
{
  NSS_GETONE(NSLCD_ACTION_NETWORK_BYNAME,
             WRITE_STRING(fp, name),
             read_netent(fp, result, buffer, buflen, errnop, h_errnop));
}

/* Note: the af parameter is ignored and is assumed to be AF_INET */
/* TODO: implement handling of af parameter */
nss_status_t _nss_ldap_getnetbyaddr_r(uint32_t addr, int UNUSED(af),
                                      struct netent *result, char *buffer,
                                      size_t buflen, int *errnop,
                                      int *h_errnop)
{
  NSS_GETONE(NSLCD_ACTION_NETWORK_BYADDR,
             WRITE_ADDRESS(fp, addr),
             read_netent(fp, result, buffer, buflen, errnop, h_errnop));
}

/* thread-local file pointer to an ongoing request */
static TLS TFILE *netentfp;

/* start a request to read all networks */
nss_status_t _nss_ldap_setnetent(int UNUSED(stayopen))
{
  NSS_SETENT(netentfp);
}

/* get a single network entry from the stream */
nss_status_t _nss_ldap_getnetent_r(struct netent *result,
                                   char *buffer, size_t buflen, int *errnop,
                                   int *h_errnop)
{
  NSS_GETENT(netentfp, NSLCD_ACTION_NETWORK_ALL,
             read_netent(netentfp, result, buffer, buflen, errnop, h_errnop));
}

/* close the stream opened by setnetent() above */
nss_status_t _nss_ldap_endnetent(void)
{
  NSS_ENDENT(netentfp);
}

#endif /* NSS_FLAVOUR_GLIBC */

#ifdef NSS_FLAVOUR_SOLARIS

#ifdef HAVE_STRUCT_NSS_XBYY_ARGS_RETURNLEN
static char *netent2str(struct netent *result, char *buffer, size_t buflen)
{
  int i, res;
  struct in_addr priv_in_addr;
  priv_in_addr.s_addr = result->n_net;
  res = snprintf(buffer, buflen, "%s %s", result->n_name, inet_ntoa(priv_in_addr));
  if ((res < 0) || (res >= (int)buflen))
    return NULL;
  if (result->n_aliases)
    for (i = 0; result->n_aliases[i]; i++)
    {
      strlcat(buffer, " ", buflen);
      strlcat(buffer, result->n_aliases[i], buflen);
    }
  if (strlen(buffer) >= buflen - 1)
    return NULL;
  return buffer;
}
#endif /* HAVE_STRUCT_NSS_XBYY_ARGS_RETURNLEN */

static nss_status_t read_result(TFILE *fp, nss_XbyY_args_t *args)
{
  READ_RESULT(netent, &args->erange, &args->h_errno);
}

/* more of a dirty hack */
#define h_errnop (&(NSS_ARGS(args)->h_errno))

static nss_status_t networks_getnetbyname(nss_backend_t UNUSED(*be), void *args)
{
  NSS_GETONE(NSLCD_ACTION_NETWORK_BYNAME,
             WRITE_STRING(fp, NSS_ARGS(args)->key.name),
             read_result(fp, args));
}

static nss_status_t networks_getnetbyaddr(nss_backend_t UNUSED(*be), void *args)
{
  NSS_GETONE(NSLCD_ACTION_NETWORK_BYADDR,
             WRITE_ADDRESS(fp, NSS_ARGS(args)->key.netaddr.net),
             read_result(fp, args));
}

static nss_status_t networks_setnetent(nss_backend_t *be, void UNUSED(*args))
{
  NSS_SETENT(LDAP_BE(be)->fp);
}

static nss_status_t networks_getnetent(nss_backend_t *be, void *args)
{
  NSS_GETENT(LDAP_BE(be)->fp, NSLCD_ACTION_NETWORK_ALL,
             read_result(LDAP_BE(be)->fp, args));
}

static nss_status_t networks_endnetent(nss_backend_t *be, void UNUSED(*args))
{
  NSS_ENDENT(LDAP_BE(be)->fp);
}

static nss_backend_op_t networks_ops[] = {
  nss_ldap_destructor,
  networks_endnetent,
  networks_setnetent,
  networks_getnetent,
  networks_getnetbyname,
  networks_getnetbyaddr
};

nss_backend_t *_nss_ldap_networks_constr(const char UNUSED(*db_name),
                                         const char UNUSED(*src_name),
                                         const char UNUSED(*cfg_args))
{
  return nss_ldap_constructor(networks_ops, sizeof(networks_ops));
}

#endif /* NSS_FLAVOUR_SOLARIS */