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/* Prototype for the setgrent functions we use here. */
typedef enum nss_status (*set_function) (void);
/* Prototype for the endgrent functions we use here. */
typedef enum nss_status (*end_function) (void);
/* Prototype for the setgrent functions we use here. */
typedef enum nss_status (*get_function) (struct group *, char *,
size_t, int *);
/* This file is also used in nscd where __libc_alloca_cutoff is not
available. */
#ifdef NOT_IN_libc
# define __libc_use_alloca(size) ((size) < __MAX_ALLOCA_CUTOFF * 4)
#endif
static enum nss_status
compat_call (service_user *nip, const char *user, gid_t group, long int *start,
long int *size, gid_t **groupsp, long int limit, int *errnop)
{
struct group grpbuf;
size_t buflen = __sysconf (_SC_GETGR_R_SIZE_MAX);
enum nss_status status;
set_function setgrent_fct;
get_function getgrent_fct;
end_function endgrent_fct;
gid_t *groups = *groupsp;
getgrent_fct = __nss_lookup_function (nip, "getgrent_r");
if (getgrent_fct == NULL)
return NSS_STATUS_UNAVAIL;
setgrent_fct = __nss_lookup_function (nip, "setgrent");
if (setgrent_fct)
{
status = DL_CALL_FCT (setgrent_fct, ());
if (status != NSS_STATUS_SUCCESS)
return status;
}
endgrent_fct = __nss_lookup_function (nip, "endgrent");
char *tmpbuf = __alloca (buflen);
bool use_malloc = false;
enum nss_status result = NSS_STATUS_SUCCESS;
do
{
while ((status = DL_CALL_FCT (getgrent_fct,
(&grpbuf, tmpbuf, buflen, errnop)),
status == NSS_STATUS_TRYAGAIN)
&& *errnop == ERANGE)
{
if (__libc_use_alloca (buflen * 2))
tmpbuf = extend_alloca (tmpbuf, buflen, buflen * 2);
else
{
buflen *= 2;
char *newbuf = realloc (use_malloc ? tmpbuf : NULL, buflen);
if (newbuf == NULL)
{
result = NSS_STATUS_TRYAGAIN;
goto done;
}
use_malloc = true;
tmpbuf = newbuf;
}
}
if (status != NSS_STATUS_SUCCESS)
goto done;
if (grpbuf.gr_gid != group)
{
char **m;
for (m = grpbuf.gr_mem; *m != NULL; ++m)
if (strcmp (*m, user) == 0)
{
/* Check whether the group is already on the list. */
long int cnt;
for (cnt = 0; cnt < *start; ++cnt)
if (groups[cnt] == grpbuf.gr_gid)
break;
if (cnt == *start)
{
/* Matches user and not yet on the list. Insert
this group. */
if (__builtin_expect (*start == *size, 0))
{
/* Need a bigger buffer. */
gid_t *newgroups;
long int newsize;
if (limit > 0 && *size == limit)
/* We reached the maximum. */
goto done;
if (limit <= 0)
newsize = 2 * *size;
else
newsize = MIN (limit, 2 * *size);
newgroups = realloc (groups,
newsize * sizeof (*groups));
if (newgroups == NULL)
goto done;
*groupsp = groups = newgroups;
*size = newsize;
}
groups[*start] = grpbuf.gr_gid;
*start += 1;
}
break;
}
}
}
while (status == NSS_STATUS_SUCCESS);
done:
if (use_malloc)
free (tmpbuf);
if (endgrent_fct)
DL_CALL_FCT (endgrent_fct, ());
return result;
}
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