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glibc  2.9
Functions | Variables
nscd_getpw_r.c File Reference
#include <assert.h>
#include <errno.h>
#include <pwd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <not-cancel.h>
#include <stdio-common/_itoa.h>
#include "nscd-client.h"
#include "nscd_proto.h"

Go to the source code of this file.

Functions

static int nscd_getpw_r (const char *key, size_t keylen, request_type type, struct passwd *resultbuf, char *buffer, size_t buflen, struct passwd **result) internal_function
int __nscd_getpwnam_r (const char *name, struct passwd *resultbuf, char *buffer, size_t buflen, struct passwd **result)
int __nscd_getpwuid_r (uid_t uid, struct passwd *resultbuf, char *buffer, size_t buflen, struct passwd **result)
 libc_locked_map_ptr (static, map_handle)
 libc_freeres_fn (pw_map_free)

Variables

int __nss_not_use_nscd_passwd

Function Documentation

int __nscd_getpwnam_r ( const char *  name,
struct passwd resultbuf,
char *  buffer,
size_t  buflen,
struct passwd **  result 
)

Definition at line 47 of file nscd_getpw_r.c.

{
  if (name == NULL)
    return -1;

  return nscd_getpw_r (name, strlen (name) + 1, GETPWBYNAME, resultbuf,
                     buffer, buflen, result);
}

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int __nscd_getpwuid_r ( uid_t  uid,
struct passwd resultbuf,
char *  buffer,
size_t  buflen,
struct passwd **  result 
)

Definition at line 58 of file nscd_getpw_r.c.

{
  char buf[3 * sizeof (uid_t)];
  buf[sizeof (buf) - 1] = '\0';
  char *cp = _itoa_word (uid, buf + sizeof (buf) - 1, 10, 0);

  return nscd_getpw_r (cp, buf + sizeof (buf) - cp, GETPWBYUID, resultbuf,
                     buffer, buflen, result);
}

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libc_freeres_fn ( pw_map_free  )

Definition at line 74 of file nscd_getpw_r.c.

{
  if (map_handle.mapped != NO_MAPPING)
    {
      void *p = map_handle.mapped;
      map_handle.mapped = NO_MAPPING;
      free (p);
    }
}
libc_locked_map_ptr ( static  ,
map_handle   
)
static int internal_function nscd_getpw_r ( const char *  key,
size_t  keylen,
request_type  type,
struct passwd resultbuf,
char *  buffer,
size_t  buflen,
struct passwd **  result 
) [static]

Definition at line 87 of file nscd_getpw_r.c.

{
  int gc_cycle;
  int nretries = 0;

  /* If the mapping is available, try to search there instead of
     communicating with the nscd.  */
  struct mapped_database *mapped;
  mapped = __nscd_get_map_ref (GETFDPW, "passwd", &map_handle, &gc_cycle);

 retry:;
  const char *pw_name = NULL;
  int retval = -1;
  const char *recend = (const char *) ~UINTMAX_C (0);
  pw_response_header pw_resp;

  if (mapped != NO_MAPPING)
    {
      struct datahead *found = __nscd_cache_search (type, key, keylen, mapped);
      if (found != NULL)
       {
         pw_name = (const char *) (&found->data[0].pwdata + 1);
         pw_resp = found->data[0].pwdata;
         recend = (const char *) found->data + found->recsize;
         /* Now check if we can trust pw_resp fields.  If GC is
            in progress, it can contain anything.  */
         if (mapped->head->gc_cycle != gc_cycle)
           {
             retval = -2;
             goto out;
           }
       }
    }

  int sock = -1;
  if (pw_name == NULL)
    {
      sock = __nscd_open_socket (key, keylen, type, &pw_resp,
                             sizeof (pw_resp));
      if (sock == -1)
       {
         __nss_not_use_nscd_passwd = 1;
         goto out;
       }
    }

  /* No value found so far.  */
  *result = NULL;

  if (__builtin_expect (pw_resp.found == -1, 0))
    {
      /* The daemon does not cache this database.  */
      __nss_not_use_nscd_passwd = 1;
      goto out_close;
    }

  if (pw_resp.found == 1)
    {
      /* Set the information we already have.  */
      resultbuf->pw_uid = pw_resp.pw_uid;
      resultbuf->pw_gid = pw_resp.pw_gid;

      char *p = buffer;
      /* get pw_name */
      resultbuf->pw_name = p;
      p += pw_resp.pw_name_len;
      /* get pw_passwd */
      resultbuf->pw_passwd = p;
      p += pw_resp.pw_passwd_len;
      /* get pw_gecos */
      resultbuf->pw_gecos = p;
      p += pw_resp.pw_gecos_len;
      /* get pw_dir */
      resultbuf->pw_dir = p;
      p += pw_resp.pw_dir_len;
      /* get pw_pshell */
      resultbuf->pw_shell = p;
      p += pw_resp.pw_shell_len;

      ssize_t total = p - buffer;
      if (__builtin_expect (pw_name + total > recend, 0))
       goto out_close;
      if (__builtin_expect (buflen < total, 0))
       {
         __set_errno (ERANGE);
         retval = ERANGE;
         goto out_close;
       }

      retval = 0;
      if (pw_name == NULL)
       {
         ssize_t nbytes = __readall (sock, buffer, total);

         if (__builtin_expect (nbytes != total, 0))
           {
             /* The `errno' to some value != ERANGE.  */
             __set_errno (ENOENT);
             retval = ENOENT;
           }
         else
           *result = resultbuf;
       }
      else
       {
         /* Copy the various strings.  */
         memcpy (resultbuf->pw_name, pw_name, total);

         /* Try to detect corrupt databases.  */
         if (resultbuf->pw_name[pw_resp.pw_name_len - 1] != '\0'
             || resultbuf->pw_passwd[pw_resp.pw_passwd_len - 1] != '\0'
             || resultbuf->pw_gecos[pw_resp.pw_gecos_len - 1] != '\0'
             || resultbuf->pw_dir[pw_resp.pw_dir_len - 1] != '\0'
             || resultbuf->pw_shell[pw_resp.pw_shell_len - 1] != '\0')
           {
             /* We cannot use the database.  */
             retval = mapped->head->gc_cycle != gc_cycle ? -2 : -1;
             goto out_close;
           }

         *result = resultbuf;
       }
    }
  else
    {
      /* Set errno to 0 to indicate no error, just no found record.  */
      __set_errno (0);
      /* Even though we have not found anything, the result is zero.  */
      retval = 0;
    }

 out_close:
  if (sock != -1)
    close_not_cancel_no_status (sock);
 out:
  if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)
    {
      /* When we come here this means there has been a GC cycle while we
        were looking for the data.  This means the data might have been
        inconsistent.  Retry if possible.  */
      if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)
       {
         /* nscd is just running gc now.  Disable using the mapping.  */
         if (atomic_decrement_val (&mapped->counter) == 0)
           __nscd_unmap (mapped);
         mapped = NO_MAPPING;
       }

      if (retval != -1)
       goto retry;
    }

  return retval;
}

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Variable Documentation

Definition at line 39 of file nscd_getpw_r.c.