nss_gns.c File Reference

#include <gnunet_private_config.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <netdb.h>
#include <sys/socket.h>
#include <nss.h>
#include <stdio.h>
#include <stdlib.h>
#include "nss_gns_query.h"
#include <arpa/inet.h>

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Macros
#define	ALIGN(idx)
	macro to align idx to 32bit boundary More...

Functions
enum nss_status	_nss_gns_gethostbyname2_r (const char *name, int af, struct hostent *result, char *buffer, size_t buflen, int *errnop, int *h_errnop)
	The gethostbyname hook executed by nsswitch. More...
enum nss_status	_nss_gns_gethostbyname_r (const char *name, struct hostent *result, char *buffer, size_t buflen, int *errnop, int *h_errnop)
	The gethostbyname hook executed by nsswitch. More...
enum nss_status	_nss_gns_gethostbyaddr_r (const void *addr, int len, int af, struct hostent *result, char *buffer, size_t buflen, int *errnop, int *h_errnop)
	The gethostbyaddr hook executed by nsswitch We can't do this so we always return NSS_STATUS_UNAVAIL. More...

Macro Definition Documentation

ALIGN

#define ALIGN

(

idx

)

Value:

    do { \
    if (idx % sizeof(void*)) \
    idx += (sizeof(void*) - idx % sizeof(void*));   /* Align on 32 bit boundary */ \
} while (0)

macro to align idx to 32bit boundary

Definition at line 39 of file nss_gns.c.

Function Documentation

_nss_gns_gethostbyname2_r()

enum nss_status _nss_gns_gethostbyname2_r	(	const char *	name,
		int	af,
		struct hostent *	result,
		char *	buffer,
		size_t	buflen,
		int *	errnop,
		int *	h_errnop
	)

The gethostbyname hook executed by nsswitch.

Parameters

name	the name to resolve
af	the address family to resolve
result	the result hostent
buffer	the result buffer
buflen	length of the buffer
errnop	idk
h_errnop	idk

Returns

a nss_status code

Definition at line 66 of file nss_gns.c.

{
  struct userdata u;
  enum nss_status status = NSS_STATUS_UNAVAIL;
  int i;
  size_t address_length;
  size_t l;
  size_t idx;
  size_t astart;
 
  if (af == AF_UNSPEC)
#ifdef NSS_IPV6_ONLY
    af = AF_INET6;
#else
    af = AF_INET;
#endif
 
#ifdef NSS_IPV4_ONLY
  if (af != AF_INET)
#elif NSS_IPV6_ONLY
  if (af != AF_INET6)
#else
  if ((af != AF_INET) &&
      (af != AF_INET6))
#endif
  {
    *errnop = EINVAL;
    *h_errnop = NO_RECOVERY;
 
    goto finish;
  }
 
  address_length = (af == AF_INET) ? sizeof(ipv4_address_t) :
                   sizeof(ipv6_address_t);
  if (buflen <
      sizeof(char*)       /* alias names */
      + strlen (name) + 1)
  {   /* official name */
    *errnop = ERANGE;
    *h_errnop = NO_RECOVERY;
    status = NSS_STATUS_TRYAGAIN;
 
    goto finish;
  }
  u.count = 0;
  u.data_len = 0;
  i = gns_resolve_name (af,
                        name,
                        &u);
  if (-1 == i)
  {
    *errnop = errno;
    status = NSS_STATUS_UNAVAIL;
    *h_errnop = NO_RECOVERY;
    goto finish;
  }
  if (-2 == i)
  {
    *errnop = ENOENT;
    *h_errnop = NO_RECOVERY;
    status = NSS_STATUS_UNAVAIL;
    goto finish;
  }
  if (-3 == i)
  {
    *errnop = ETIMEDOUT;
    *h_errnop = HOST_NOT_FOUND;
    status = NSS_STATUS_NOTFOUND;
    goto finish;
  }
  if (0 == u.count)
  {
    *errnop = 0;   /* success */
    *h_errnop = NO_DATA;   /* success */
    status = NSS_STATUS_NOTFOUND;
    goto finish;
  }
  /* Alias names */
  *((char **) buffer) = NULL;
  result->h_aliases = (char **) buffer;
  idx = sizeof(char*);
 
  /* Official name */
  strcpy (buffer + idx,
          name);
  result->h_name = buffer + idx;
  idx += strlen (name) + 1;
 
  ALIGN (idx);
 
  result->h_addrtype = af;
  result->h_length = address_length;
 
  /* Check if there's enough space for the addresses */
  if (buflen < idx + u.data_len + sizeof(char*) * (u.count + 1))
  {
    *errnop = ERANGE;
    *h_errnop = NO_RECOVERY;
    status = NSS_STATUS_TRYAGAIN;
    goto finish;
  }
  /* Addresses */
  astart = idx;
  l = u.count * address_length;
  if (0 != l)
    memcpy (buffer + astart,
            &u.data,
            l);
  /* address_length is a multiple of 32bits, so idx is still aligned
   * correctly */
  idx += l;
 
  /* Address array address_length is always a multiple of 32bits */
  for (i = 0; i < u.count; i++)
    ((char **) (buffer + idx))[i] = buffer + astart + address_length * i;
  ((char **) (buffer + idx))[i] = NULL;
  result->h_addr_list = (char **) (buffer + idx);
 
  status = NSS_STATUS_SUCCESS;
 
finish:
  return status;
}

References ALIGN, gns_resolve_name(), name, result, status, and u.

Referenced by _nss_gns_gethostbyname_r().

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_nss_gns_gethostbyname_r()

enum nss_status _nss_gns_gethostbyname_r	(	const char *	name,
		struct hostent *	result,
		char *	buffer,
		size_t	buflen,
		int *	errnop,
		int *	h_errnop
	)

The gethostbyname hook executed by nsswitch.

Parameters

	name	the name to resolve
	result	the result hostent
	buffer	the result buffer
	buflen	length of the buffer
[out]	errnop	the low-level error code to return to the application
	h_errnop	idk

Returns

a nss_status code

Definition at line 215 of file nss_gns.c.

{
  return _nss_gns_gethostbyname2_r (name,
                                    AF_UNSPEC,
                                    result,
                                    buffer,
                                    buflen,
                                    errnop,
                                    h_errnop);
}

References _nss_gns_gethostbyname2_r(), name, and result.

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_nss_gns_gethostbyaddr_r()

enum nss_status _nss_gns_gethostbyaddr_r	(	const void *	addr,
		int	len,
		int	af,
		struct hostent *	result,
		char *	buffer,
		size_t	buflen,
		int *	errnop,
		int *	h_errnop
	)

The gethostbyaddr hook executed by nsswitch We can't do this so we always return NSS_STATUS_UNAVAIL.

Parameters

	addr	the address to resolve
	len	the length of the address
	af	the address family of the address
	result	the result hostent
	buffer	the result buffer
	buflen	length of the buffer
[out]	errnop	the low-level error code to return to the application
	h_errnop	idk

Returns

NSS_STATUS_UNAVAIL

Definition at line 255 of file nss_gns.c.

{
  (void) addr;
  (void) len;
  (void) af;
  (void) result;
  (void) buffer;
  (void) buflen;
  *errnop = EINVAL;
  *h_errnop = NO_RECOVERY;
  /* NOTE we allow to leak this into DNS so no NOTFOUND */
  return NSS_STATUS_UNAVAIL;
}

References result.