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glibc  2.9
Classes | Defines | Functions | Variables
auth_unix.c File Reference
#include <errno.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <libintl.h>
#include <sys/param.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/auth_unix.h>

Go to the source code of this file.

Classes

struct  audata

Defines

#define AUTH_PRIVATE(auth)   ((struct audata *)auth->ah_private)
#define ALLOCA_LIMIT   (1024 / sizeof (gid_t))

Functions

static void authunix_nextverf (AUTH *)
static bool_t authunix_marshal (AUTH *, XDR *)
static bool_t authunix_validate (AUTH *, struct opaque_auth *)
static bool_t authunix_refresh (AUTH *)
static void authunix_destroy (AUTH *)
static bool_t marshal_new_auth (AUTH *)
AUTHauthunix_create_default (void)

Variables

static struct auth_ops

Class Documentation

struct audata

Definition at line 79 of file auth_unix.c.

Class Members
char au_marshed
u_int au_mpos
u_long au_shfaults

Define Documentation

#define ALLOCA_LIMIT   (1024 / sizeof (gid_t))
#define AUTH_PRIVATE (   auth)    ((struct audata *)auth->ah_private)

Definition at line 86 of file auth_unix.c.


Function Documentation

Definition at line 162 of file auth_unix.c.

{
  char machname[MAX_MACHINE_NAME + 1];

  if (__gethostname (machname, MAX_MACHINE_NAME) == -1)
    abort ();
  machname[MAX_MACHINE_NAME] = 0;
  uid_t uid = __geteuid ();
  gid_t gid = __getegid ();

  int max_nr_groups;
  /* When we have to try a second time, do not use alloca() again.  We
     might have reached the stack limit already.  */
  bool retry = false;
 again:
  /* Ask the kernel how many groups there are exactly.  Note that we
     might have to redo all this if the number of groups has changed
     between the two calls.  */
  max_nr_groups = __getgroups (0, NULL);

  /* Just some random reasonable stack limit.  */
#define ALLOCA_LIMIT (1024 / sizeof (gid_t))
  gid_t *gids = NULL;
  if (max_nr_groups < ALLOCA_LIMIT && ! retry)
    gids = (gid_t *) alloca (max_nr_groups * sizeof (gid_t));
  else
    {
      gids = (gid_t *) malloc (max_nr_groups * sizeof (gid_t));
      if (gids == NULL)
       return NULL;
    }

  int len = __getgroups (max_nr_groups, gids);
  if (len == -1)
    {
      if (errno == EINVAL)
       {
         /* New groups added in the meantime.  Try again.  */
         if (max_nr_groups >= ALLOCA_LIMIT || retry)
           free (gids);
         retry = true;
         goto again;
       }
      /* No other error can happen.  */
      abort ();
    }

  /* This braindamaged Sun code forces us here to truncate the
     list of groups to NGRPS members since the code in
     authuxprot.c transforms a fixed array.  Grrr.  */
  AUTH *result = INTUSE(authunix_create) (machname, uid, gid, MIN (NGRPS, len),
                                     gids);

  if (max_nr_groups >= ALLOCA_LIMIT || retry)
    free (gids);

  return result;
}

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static void authunix_destroy ( AUTH auth) [static]

Definition at line 318 of file auth_unix.c.

{
  struct audata *au = AUTH_PRIVATE (auth);

  mem_free (au->au_origcred.oa_base, au->au_origcred.oa_length);

  if (au->au_shcred.oa_base != NULL)
    mem_free (au->au_shcred.oa_base, au->au_shcred.oa_length);

  mem_free (auth->ah_private, sizeof (struct audata));

  if (auth->ah_verf.oa_base != NULL)
    mem_free (auth->ah_verf.oa_base, auth->ah_verf.oa_length);

  mem_free ((caddr_t) auth, sizeof (*auth));
}
static bool_t authunix_marshal ( AUTH auth,
XDR xdrs 
) [static]

Definition at line 233 of file auth_unix.c.

{
  struct audata *au = AUTH_PRIVATE (auth);

  return XDR_PUTBYTES (xdrs, au->au_marshed, au->au_mpos);
}
static void authunix_nextverf ( AUTH auth) [static]

Definition at line 227 of file auth_unix.c.

{
  /* no action necessary */
}
static bool_t authunix_refresh ( AUTH auth) [static]

Definition at line 275 of file auth_unix.c.

{
  struct audata *au = AUTH_PRIVATE (auth);
  struct authunix_parms aup;
  struct timeval now;
  XDR xdrs;
  int stat;

  if (auth->ah_cred.oa_base == au->au_origcred.oa_base)
    {
      /* there is no hope.  Punt */
      return FALSE;
    }
  au->au_shfaults++;

  /* first deserialize the creds back into a struct authunix_parms */
  aup.aup_machname = NULL;
  aup.aup_gids = (gid_t *) NULL;
  INTUSE(xdrmem_create) (&xdrs, au->au_origcred.oa_base,
                      au->au_origcred.oa_length, XDR_DECODE);
  stat = INTUSE(xdr_authunix_parms) (&xdrs, &aup);
  if (!stat)
    goto done;

  /* update the time and serialize in place */
  (void) __gettimeofday (&now, (struct timezone *) 0);
  aup.aup_time = now.tv_sec;
  xdrs.x_op = XDR_ENCODE;
  XDR_SETPOS (&xdrs, 0);
  stat = INTUSE(xdr_authunix_parms) (&xdrs, &aup);
  if (!stat)
    goto done;
  auth->ah_cred = au->au_origcred;
  marshal_new_auth (auth);
done:
  /* free the struct authunix_parms created by deserializing */
  xdrs.x_op = XDR_FREE;
  (void) INTUSE(xdr_authunix_parms) (&xdrs, &aup);
  XDR_DESTROY (&xdrs);
  return stat;
}

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static bool_t authunix_validate ( AUTH auth,
struct opaque_auth verf 
) [static]

Definition at line 241 of file auth_unix.c.

{
  struct audata *au;
  XDR xdrs;

  if (verf->oa_flavor == AUTH_SHORT)
    {
      au = AUTH_PRIVATE (auth);
      INTUSE(xdrmem_create) (&xdrs, verf->oa_base, verf->oa_length,
                          XDR_DECODE);

      if (au->au_shcred.oa_base != NULL)
       {
         mem_free (au->au_shcred.oa_base,
                  au->au_shcred.oa_length);
         au->au_shcred.oa_base = NULL;
       }
      if (INTUSE(xdr_opaque_auth) (&xdrs, &au->au_shcred))
       {
         auth->ah_cred = au->au_shcred;
       }
      else
       {
         xdrs.x_op = XDR_FREE;
         (void) INTUSE(xdr_opaque_auth) (&xdrs, &au->au_shcred);
         au->au_shcred.oa_base = NULL;
         auth->ah_cred = au->au_origcred;
       }
      marshal_new_auth (auth);
    }
  return TRUE;
}

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static bool_t internal_function marshal_new_auth ( AUTH auth) [static]

Definition at line 88 of file auth_unix.c.

{
  struct authunix_parms aup;
  char mymem[MAX_AUTH_BYTES];
  struct timeval now;
  XDR xdrs;
  AUTH *auth;
  struct audata *au;

  /*
   * Allocate and set up auth handle
   */
  auth = (AUTH *) mem_alloc (sizeof (*auth));
  au = (struct audata *) mem_alloc (sizeof (*au));
  if (auth == NULL || au == NULL)
    {
no_memory:
      (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
      mem_free (auth, sizeof (*auth));
      mem_free (au, sizeof (*au));
      return NULL;
    }
  auth->ah_ops = (struct auth_ops *) &auth_unix_ops;
  auth->ah_private = (caddr_t) au;
  auth->ah_verf = au->au_shcred = _null_auth;
  au->au_shfaults = 0;

  /*
   * fill in param struct from the given params
   */
  (void) __gettimeofday (&now, (struct timezone *) 0);
  aup.aup_time = now.tv_sec;
  aup.aup_machname = machname;
  aup.aup_uid = uid;
  aup.aup_gid = gid;
  aup.aup_len = (u_int) len;
  aup.aup_gids = aup_gids;

  /*
   * Serialize the parameters into origcred
   */
  INTUSE(xdrmem_create) (&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
  if (!INTUSE(xdr_authunix_parms) (&xdrs, &aup))
    abort ();
  au->au_origcred.oa_length = len = XDR_GETPOS (&xdrs);
  au->au_origcred.oa_flavor = AUTH_UNIX;
  au->au_origcred.oa_base = mem_alloc ((u_int) len);
  if (au->au_origcred.oa_base == NULL)
    goto no_memory;
  memcpy(au->au_origcred.oa_base, mymem, (u_int) len);

  /*
   * set auth handle to reflect new cred.
   */
  auth->ah_cred = au->au_origcred;
  marshal_new_auth (auth);
  return auth;
}

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Variable Documentation

struct auth_ops [static]