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23ed36735a
glibc/nss/nss_compat/compat-pwd.c
Florian Weimer 23ed36735a nss_compat: Do not use mmap to read database files (bug 26258) 
This avoids crashes in case the files are truncated for some reason.
For typically file sizes, it is also going to be slightly faster.
Using __nss_files_fopen instead mirrors what nss_files does.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-21 07:33:08 +02:00

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/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1996.
The GNU C 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.
The GNU C 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 the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <nss.h>
#include <nsswitch.h>
#include <pwd.h>
#include <stdio_ext.h>
#include <string.h>
#include <libc-lock.h>
#include <kernel-features.h>
#include <nss_files.h>
#include "netgroup.h"
#include "nisdomain.h"
NSS_DECLARE_MODULE_FUNCTIONS (compat)
static service_user *ni;
static enum nss_status (*setpwent_impl) (int stayopen);
static enum nss_status (*getpwnam_r_impl) (const char *name,
struct passwd * pwd, char *buffer,
size_t buflen, int *errnop);
static enum nss_status (*getpwuid_r_impl) (uid_t uid, struct passwd * pwd,
char *buffer, size_t buflen,
int *errnop);
static enum nss_status (*getpwent_r_impl) (struct passwd * pwd, char *buffer,
size_t buflen, int *errnop);
static enum nss_status (*endpwent_impl) (void);
/* Get the declaration of the parser function. */
#define ENTNAME pwent
#define STRUCTURE passwd
#define EXTERN_PARSER
#include <nss/nss_files/files-parse.c>
/* Structure for remembering -@netgroup and -user members ... */
#define BLACKLIST_INITIAL_SIZE 512
#define BLACKLIST_INCREMENT 256
struct blacklist_t
{
char *data;
int current;
int size;
};
struct ent_t
{
bool netgroup;
bool first;
bool files;
enum nss_status setent_status;
FILE *stream;
struct blacklist_t blacklist;
struct passwd pwd;
struct __netgrent netgrdata;
};
typedef struct ent_t ent_t;
static ent_t ext_ent = { false, false, true, NSS_STATUS_SUCCESS, NULL,
{ NULL, 0, 0 },
{ NULL, NULL, 0, 0, NULL, NULL, NULL }};
/* Protect global state against multiple changers. */
__libc_lock_define_initialized (static, lock)
/* Prototypes for local functions. */
static void blacklist_store_name (const char *, ent_t *);
static bool in_blacklist (const char *, int, ent_t *);
/* Initialize the NSS interface/functions. The calling function must
hold the lock. */
static void
init_nss_interface (void)
{
if (__nss_database_lookup2 ("passwd_compat", NULL, "nis", &ni) >= 0)
{
setpwent_impl = __nss_lookup_function (ni, "setpwent");
getpwnam_r_impl = __nss_lookup_function (ni, "getpwnam_r");
getpwuid_r_impl = __nss_lookup_function (ni, "getpwuid_r");
getpwent_r_impl = __nss_lookup_function (ni, "getpwent_r");
endpwent_impl = __nss_lookup_function (ni, "endpwent");
}
}
static void
give_pwd_free (struct passwd *pwd)
{
free (pwd->pw_name);
free (pwd->pw_passwd);
free (pwd->pw_gecos);
free (pwd->pw_dir);
free (pwd->pw_shell);
memset (pwd, '\0', sizeof (struct passwd));
}
static size_t
pwd_need_buflen (struct passwd *pwd)
{
size_t len = 0;
if (pwd->pw_passwd != NULL)
len += strlen (pwd->pw_passwd) + 1;
if (pwd->pw_gecos != NULL)
len += strlen (pwd->pw_gecos) + 1;
if (pwd->pw_dir != NULL)
len += strlen (pwd->pw_dir) + 1;
if (pwd->pw_shell != NULL)
len += strlen (pwd->pw_shell) + 1;
return len;
}
static void
copy_pwd_changes (struct passwd *dest, struct passwd *src,
char *buffer, size_t buflen)
{
if (src->pw_passwd != NULL && strlen (src->pw_passwd))
{
if (buffer == NULL)
dest->pw_passwd = strdup (src->pw_passwd);
else if (dest->pw_passwd
&& strlen (dest->pw_passwd) >= strlen (src->pw_passwd))
strcpy (dest->pw_passwd, src->pw_passwd);
else
{
dest->pw_passwd = buffer;
strcpy (dest->pw_passwd, src->pw_passwd);
buffer += strlen (dest->pw_passwd) + 1;
buflen = buflen - (strlen (dest->pw_passwd) + 1);
}
}
if (src->pw_gecos != NULL && strlen (src->pw_gecos))
{
if (buffer == NULL)
dest->pw_gecos = strdup (src->pw_gecos);
else if (dest->pw_gecos
&& strlen (dest->pw_gecos) >= strlen (src->pw_gecos))
strcpy (dest->pw_gecos, src->pw_gecos);
else
{
dest->pw_gecos = buffer;
strcpy (dest->pw_gecos, src->pw_gecos);
buffer += strlen (dest->pw_gecos) + 1;
buflen = buflen - (strlen (dest->pw_gecos) + 1);
}
}
if (src->pw_dir != NULL && strlen (src->pw_dir))
{
if (buffer == NULL)
dest->pw_dir = strdup (src->pw_dir);
else if (dest->pw_dir && strlen (dest->pw_dir) >= strlen (src->pw_dir))
strcpy (dest->pw_dir, src->pw_dir);
else
{
dest->pw_dir = buffer;
strcpy (dest->pw_dir, src->pw_dir);
buffer += strlen (dest->pw_dir) + 1;
buflen = buflen - (strlen (dest->pw_dir) + 1);
}
}
if (src->pw_shell != NULL && strlen (src->pw_shell))
{
if (buffer == NULL)
dest->pw_shell = strdup (src->pw_shell);
else if (dest->pw_shell
&& strlen (dest->pw_shell) >= strlen (src->pw_shell))
strcpy (dest->pw_shell, src->pw_shell);
else
{
dest->pw_shell = buffer;
strcpy (dest->pw_shell, src->pw_shell);
buffer += strlen (dest->pw_shell) + 1;
buflen = buflen - (strlen (dest->pw_shell) + 1);
}
}
}
static enum nss_status
internal_setpwent (ent_t *ent, int stayopen, int needent)
{
enum nss_status status = NSS_STATUS_SUCCESS;
ent->first = ent->netgroup = false;
ent->files = true;
ent->setent_status = NSS_STATUS_SUCCESS;
/* If something was left over free it. */
if (ent->netgroup)
__internal_endnetgrent (&ent->netgrdata);
if (ent->blacklist.data != NULL)
{
ent->blacklist.current = 1;
ent->blacklist.data[0] = '|';
ent->blacklist.data[1] = '\0';
}
else
ent->blacklist.current = 0;
if (ent->stream == NULL)
{
ent->stream = __nss_files_fopen ("/etc/passwd");
if (ent->stream == NULL)
status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
}
else
rewind (ent->stream);
give_pwd_free (&ent->pwd);
if (needent && status == NSS_STATUS_SUCCESS && setpwent_impl)
ent->setent_status = setpwent_impl (stayopen);
return status;
}
enum nss_status
_nss_compat_setpwent (int stayopen)
{
enum nss_status result;
__libc_lock_lock (lock);
if (ni == NULL)
init_nss_interface ();
result = internal_setpwent (&ext_ent, stayopen, 1);
__libc_lock_unlock (lock);
return result;
}
static enum nss_status __attribute_warn_unused_result__
internal_endpwent (ent_t *ent)
{
if (ent->stream != NULL)
{
fclose (ent->stream);
ent->stream = NULL;
}
if (ent->netgroup)
__internal_endnetgrent (&ent->netgrdata);
ent->first = ent->netgroup = false;
if (ent->blacklist.data != NULL)
{
ent->blacklist.current = 1;
ent->blacklist.data[0] = '|';
ent->blacklist.data[1] = '\0';
}
else
ent->blacklist.current = 0;
give_pwd_free (&ent->pwd);
return NSS_STATUS_SUCCESS;
}
/* Like internal_endpwent, but preserve errno in all cases. */
static void
internal_endpwent_noerror (ent_t *ent)
{
int saved_errno = errno;
enum nss_status unused __attribute__ ((unused)) = internal_endpwent (ent);
__set_errno (saved_errno);
}
enum nss_status
_nss_compat_endpwent (void)
{
enum nss_status result;
__libc_lock_lock (lock);
if (endpwent_impl)
endpwent_impl ();
result = internal_endpwent (&ext_ent);
__libc_lock_unlock (lock);
return result;
}
static enum nss_status
getpwent_next_nss_netgr (const char *name, struct passwd *result, ent_t *ent,
char *group, char *buffer, size_t buflen,
int *errnop)
{
char *curdomain = NULL, *host, *user, *domain, *p2;
int status;
size_t p2len;
/* Leave function if NSS module does not support getpwnam_r,
we need this function here. */
if (!getpwnam_r_impl)
return NSS_STATUS_UNAVAIL;
if (ent->first)
{
memset (&ent->netgrdata, 0, sizeof (struct __netgrent));
__internal_setnetgrent (group, &ent->netgrdata);
ent->first = false;
}
while (1)
{
status = __internal_getnetgrent_r (&host, &user, &domain,
&ent->netgrdata, buffer, buflen,
errnop);
if (status != 1)
{
__internal_endnetgrent (&ent->netgrdata);
ent->netgroup = 0;
give_pwd_free (&ent->pwd);
return NSS_STATUS_RETURN;
}
if (user == NULL || user[0] == '-')
continue;
if (domain != NULL)
{
if (curdomain == NULL
&& __nss_get_default_domain (&curdomain) != 0)
{
__internal_endnetgrent (&ent->netgrdata);
ent->netgroup = false;
give_pwd_free (&ent->pwd);
return NSS_STATUS_UNAVAIL;
}
if (strcmp (curdomain, domain) != 0)
continue;
}
/* If name != NULL, we are called from getpwnam. */
if (name != NULL)
if (strcmp (user, name) != 0)
continue;
p2len = pwd_need_buflen (&ent->pwd);
if (p2len > buflen)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
p2 = buffer + (buflen - p2len);
buflen -= p2len;
if (getpwnam_r_impl (user, result, buffer, buflen, errnop)
!= NSS_STATUS_SUCCESS)
continue;
if (!in_blacklist (result->pw_name, strlen (result->pw_name), ent))
{
/* Store the User in the blacklist for possible the "+" at the
end of /etc/passwd */
blacklist_store_name (result->pw_name, ent);
copy_pwd_changes (result, &ent->pwd, p2, p2len);
break;
}
}
return NSS_STATUS_SUCCESS;
}
/* get the next user from NSS (+ entry) */
static enum nss_status
getpwent_next_nss (struct passwd *result, ent_t *ent, char *buffer,
size_t buflen, int *errnop)
{
enum nss_status status;
char *p2;
size_t p2len;
/* Return if NSS module does not support getpwent_r. */
if (!getpwent_r_impl)
return NSS_STATUS_UNAVAIL;
/* If the setpwent call failed, say so. */
if (ent->setent_status != NSS_STATUS_SUCCESS)
return ent->setent_status;
p2len = pwd_need_buflen (&ent->pwd);
if (p2len > buflen)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
p2 = buffer + (buflen - p2len);
buflen -= p2len;
if (ent->first)
ent->first = false;
do
{
if ((status = getpwent_r_impl (result, buffer, buflen, errnop))
!= NSS_STATUS_SUCCESS)
return status;
}
while (in_blacklist (result->pw_name, strlen (result->pw_name), ent));
copy_pwd_changes (result, &ent->pwd, p2, p2len);
return NSS_STATUS_SUCCESS;
}
/* This function handle the +user entrys in /etc/passwd */
static enum nss_status
getpwnam_plususer (const char *name, struct passwd *result, ent_t *ent,
char *buffer, size_t buflen, int *errnop)
{
if (!getpwnam_r_impl)
return NSS_STATUS_UNAVAIL;
struct passwd pwd;
memset (&pwd, '\0', sizeof (struct passwd));
copy_pwd_changes (&pwd, result, NULL, 0);
size_t plen = pwd_need_buflen (&pwd);
if (plen > buflen)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
char *p = buffer + (buflen - plen);
buflen -= plen;
enum nss_status status = getpwnam_r_impl (name, result, buffer, buflen,
errnop);
if (status != NSS_STATUS_SUCCESS)
return status;
if (in_blacklist (result->pw_name, strlen (result->pw_name), ent))
return NSS_STATUS_NOTFOUND;
copy_pwd_changes (result, &pwd, p, plen);
give_pwd_free (&pwd);
/* We found the entry. */
return NSS_STATUS_SUCCESS;
}
static enum nss_status
getpwent_next_file (struct passwd *result, ent_t *ent,
char *buffer, size_t buflen, int *errnop)
{
struct parser_data *data = (void *) buffer;
while (1)
{
fpos_t pos;
char *p;
int parse_res;
do
{
/* We need at least 3 characters for one line. */
if (__glibc_unlikely (buflen < 3))
{
erange:
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
fgetpos (ent->stream, &pos);
buffer[buflen - 1] = '\xff';
p = fgets_unlocked (buffer, buflen, ent->stream);
if (p == NULL && feof_unlocked (ent->stream))
return NSS_STATUS_NOTFOUND;
if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
{
erange_reset:
fsetpos (ent->stream, &pos);
goto erange;
}
/* Terminate the line for any case. */
buffer[buflen - 1] = '\0';
/* Skip leading blanks. */
while (isspace (*p))
++p;
}
while (*p == '\0' || *p == '#' /* Ignore empty and comment lines. */
/* Parse the line. If it is invalid, loop to
get the next line of the file to parse. */
|| !(parse_res = _nss_files_parse_pwent (p, result, data, buflen,
errnop)));
if (__glibc_unlikely (parse_res == -1))
/* The parser ran out of space. */
goto erange_reset;
if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
/* This is a real entry. */
break;
/* -@netgroup */
if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
&& result->pw_name[2] != '\0')
{
/* XXX Do not use fixed length buffer. */
char buf2[1024];
char *user, *host, *domain;
struct __netgrent netgrdata;
memset (&netgrdata, 0, sizeof (struct __netgrent));
__internal_setnetgrent (&result->pw_name[2], &netgrdata);
while (__internal_getnetgrent_r (&host, &user, &domain, &netgrdata,
buf2, sizeof (buf2), errnop))
{
if (user != NULL && user[0] != '-')
blacklist_store_name (user, ent);
}
__internal_endnetgrent (&netgrdata);
continue;
}
/* +@netgroup */
if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
&& result->pw_name[2] != '\0')
{
enum nss_status status;
ent->netgroup = true;
ent->first = true;
copy_pwd_changes (&ent->pwd, result, NULL, 0);
status = getpwent_next_nss_netgr (NULL, result, ent,
&result->pw_name[2],
buffer, buflen, errnop);
if (status == NSS_STATUS_RETURN)
continue;
else
return status;
}
/* -user */
if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
&& result->pw_name[1] != '@')
{
blacklist_store_name (&result->pw_name[1], ent);
continue;
}
/* +user */
if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
&& result->pw_name[1] != '@')
{
size_t len = strlen (result->pw_name);
char buf[len];
enum nss_status status;
/* Store the User in the blacklist for the "+" at the end of
/etc/passwd */
memcpy (buf, &result->pw_name[1], len);
status = getpwnam_plususer (&result->pw_name[1], result, ent,
buffer, buflen, errnop);
blacklist_store_name (buf, ent);
if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
break;
else if (status == NSS_STATUS_RETURN /* We couldn't parse the entry */
|| status == NSS_STATUS_NOTFOUND) /* entry doesn't exist */
continue;
else
{
if (status == NSS_STATUS_TRYAGAIN)
{
/* The parser ran out of space */
fsetpos (ent->stream, &pos);
*errnop = ERANGE;
}
return status;
}
}
/* +:... */
if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
{
ent->files = false;
ent->first = true;
copy_pwd_changes (&ent->pwd, result, NULL, 0);
return getpwent_next_nss (result, ent, buffer, buflen, errnop);
}
}
return NSS_STATUS_SUCCESS;
}
static enum nss_status
internal_getpwent_r (struct passwd *pw, ent_t *ent, char *buffer,
size_t buflen, int *errnop)
{
if (ent->netgroup)
{
enum nss_status status;
/* We are searching members in a netgroup */
/* Since this is not the first call, we don't need the group name */
status = getpwent_next_nss_netgr (NULL, pw, ent, NULL, buffer, buflen,
errnop);
if (status == NSS_STATUS_RETURN)
return getpwent_next_file (pw, ent, buffer, buflen, errnop);
else
return status;
}
else if (ent->files)
return getpwent_next_file (pw, ent, buffer, buflen, errnop);
else
return getpwent_next_nss (pw, ent, buffer, buflen, errnop);
}
enum nss_status
_nss_compat_getpwent_r (struct passwd *pwd, char *buffer, size_t buflen,
int *errnop)
{
enum nss_status result = NSS_STATUS_SUCCESS;
__libc_lock_lock (lock);
/* Be prepared that the setpwent function was not called before. */
if (ni == NULL)
init_nss_interface ();
if (ext_ent.stream == NULL)
result = internal_setpwent (&ext_ent, 1, 1);
if (result == NSS_STATUS_SUCCESS)
result = internal_getpwent_r (pwd, &ext_ent, buffer, buflen, errnop);
__libc_lock_unlock (lock);
return result;
}
/* Searches in /etc/passwd and the NIS/NIS+ map for a special user */
static enum nss_status
internal_getpwnam_r (const char *name, struct passwd *result, ent_t *ent,
char *buffer, size_t buflen, int *errnop)
{
struct parser_data *data = (void *) buffer;
while (1)
{
fpos_t pos;
char *p;
int parse_res;
do
{
/* We need at least 3 characters for one line. */
if (__glibc_unlikely (buflen < 3))
{
erange:
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
fgetpos (ent->stream, &pos);
buffer[buflen - 1] = '\xff';
p = fgets_unlocked (buffer, buflen, ent->stream);
if (p == NULL && feof_unlocked (ent->stream))
{
return NSS_STATUS_NOTFOUND;
}
if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
{
erange_reset:
fsetpos (ent->stream, &pos);
goto erange;
}
/* Terminate the line for any case. */
buffer[buflen - 1] = '\0';
/* Skip leading blanks. */
while (isspace (*p))
++p;
}
while (*p == '\0' || *p == '#' /* Ignore empty and comment lines. */
/* Parse the line. If it is invalid, loop to
get the next line of the file to parse. */
|| !(parse_res = _nss_files_parse_pwent (p, result, data, buflen,
errnop)));
if (__glibc_unlikely (parse_res == -1))
/* The parser ran out of space. */
goto erange_reset;
/* This is a real entry. */
if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
{
if (strcmp (result->pw_name, name) == 0)
return NSS_STATUS_SUCCESS;
else
continue;
}
/* -@netgroup */
if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
&& result->pw_name[2] != '\0')
{
if (innetgr (&result->pw_name[2], NULL, name, NULL))
return NSS_STATUS_NOTFOUND;
continue;
}
/* +@netgroup */
if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
&& result->pw_name[2] != '\0')
{
enum nss_status status;
if (innetgr (&result->pw_name[2], NULL, name, NULL))
{
status = getpwnam_plususer (name, result, ent, buffer,
buflen, errnop);
if (status == NSS_STATUS_RETURN)
continue;
return status;
}
continue;
}
/* -user */
if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
&& result->pw_name[1] != '@')
{
if (strcmp (&result->pw_name[1], name) == 0)
return NSS_STATUS_NOTFOUND;
else
continue;
}
/* +user */
if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
&& result->pw_name[1] != '@')
{
if (strcmp (name, &result->pw_name[1]) == 0)
{
enum nss_status status;
status = getpwnam_plususer (name, result, ent, buffer, buflen,
errnop);
if (status == NSS_STATUS_RETURN)
/* We couldn't parse the entry */
return NSS_STATUS_NOTFOUND;
else
return status;
}
}
/* +:... */
if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
{
enum nss_status status;
status = getpwnam_plususer (name, result, ent,
buffer, buflen, errnop);
if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
break;
else if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
return NSS_STATUS_NOTFOUND;
else
return status;
}
}
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_compat_getpwnam_r (const char *name, struct passwd *pwd,
char *buffer, size_t buflen, int *errnop)
{
enum nss_status result;
ent_t ent = { false, false, true, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0 },
{ NULL, NULL, 0, 0, NULL, NULL, NULL }};
if (name[0] == '-' || name[0] == '+')
return NSS_STATUS_NOTFOUND;
__libc_lock_lock (lock);
if (ni == NULL)
init_nss_interface ();
__libc_lock_unlock (lock);
result = internal_setpwent (&ent, 0, 0);
if (result == NSS_STATUS_SUCCESS)
result = internal_getpwnam_r (name, pwd, &ent, buffer, buflen, errnop);
internal_endpwent_noerror (&ent);
return result;
}
/* This function handle the + entry in /etc/passwd for getpwuid */
static enum nss_status
getpwuid_plususer (uid_t uid, struct passwd *result, char *buffer,
size_t buflen, int *errnop)
{
struct passwd pwd;
char *p;
size_t plen;
if (!getpwuid_r_impl)
return NSS_STATUS_UNAVAIL;
memset (&pwd, '\0', sizeof (struct passwd));
copy_pwd_changes (&pwd, result, NULL, 0);
plen = pwd_need_buflen (&pwd);
if (plen > buflen)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
p = buffer + (buflen - plen);
buflen -= plen;
if (getpwuid_r_impl (uid, result, buffer, buflen, errnop) ==
NSS_STATUS_SUCCESS)
{
copy_pwd_changes (result, &pwd, p, plen);
give_pwd_free (&pwd);
/* We found the entry. */
return NSS_STATUS_SUCCESS;
}
else
{
/* Give buffer the old len back */
buflen += plen;
give_pwd_free (&pwd);
}
return NSS_STATUS_RETURN;
}
/* Searches in /etc/passwd and the NSS subsystem for a special user id */
static enum nss_status
internal_getpwuid_r (uid_t uid, struct passwd *result, ent_t *ent,
char *buffer, size_t buflen, int *errnop)
{
struct parser_data *data = (void *) buffer;
while (1)
{
fpos_t pos;
char *p;
int parse_res;
do
{
/* We need at least 3 characters for one line. */
if (__glibc_unlikely (buflen < 3))
{
erange:
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
fgetpos (ent->stream, &pos);
buffer[buflen - 1] = '\xff';
p = fgets_unlocked (buffer, buflen, ent->stream);
if (p == NULL && feof_unlocked (ent->stream))
return NSS_STATUS_NOTFOUND;
if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
{
erange_reset:
fsetpos (ent->stream, &pos);
goto erange;
}
/* Terminate the line for any case. */
buffer[buflen - 1] = '\0';
/* Skip leading blanks. */
while (isspace (*p))
++p;
}
while (*p == '\0' || *p == '#' /* Ignore empty and comment lines. */
/* Parse the line. If it is invalid, loop to
get the next line of the file to parse. */
|| !(parse_res = _nss_files_parse_pwent (p, result, data, buflen,
errnop)));
if (__glibc_unlikely (parse_res == -1))
/* The parser ran out of space. */
goto erange_reset;
/* This is a real entry. */
if (result->pw_name[0] != '+' && result->pw_name[0] != '-')
{
if (result->pw_uid == uid)
return NSS_STATUS_SUCCESS;
else
continue;
}
/* -@netgroup */
if (result->pw_name[0] == '-' && result->pw_name[1] == '@'
&& result->pw_name[2] != '\0')
{
/* -1, because we remove first two character of pw_name. */
size_t len = strlen (result->pw_name) - 1;
char buf[len];
enum nss_status status;
memcpy (buf, &result->pw_name[2], len);
status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
if (status == NSS_STATUS_SUCCESS
&& innetgr (buf, NULL, result->pw_name, NULL))
return NSS_STATUS_NOTFOUND;
continue;
}
/* +@netgroup */
if (result->pw_name[0] == '+' && result->pw_name[1] == '@'
&& result->pw_name[2] != '\0')
{
/* -1, because we remove first two characters of pw_name. */
size_t len = strlen (result->pw_name) - 1;
char buf[len];
enum nss_status status;
memcpy (buf, &result->pw_name[2], len);
status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
if (status == NSS_STATUS_RETURN)
continue;
if (status == NSS_STATUS_SUCCESS)
{
if (innetgr (buf, NULL, result->pw_name, NULL))
return NSS_STATUS_SUCCESS;
}
else if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
return NSS_STATUS_NOTFOUND;
else
return status;
continue;
}
/* -user */
if (result->pw_name[0] == '-' && result->pw_name[1] != '\0'
&& result->pw_name[1] != '@')
{
size_t len = strlen (result->pw_name);
char buf[len];
enum nss_status status;
memcpy (buf, &result->pw_name[1], len);
status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
if (status == NSS_STATUS_SUCCESS
&& innetgr (buf, NULL, result->pw_name, NULL))
return NSS_STATUS_NOTFOUND;
continue;
}
/* +user */
if (result->pw_name[0] == '+' && result->pw_name[1] != '\0'
&& result->pw_name[1] != '@')
{
size_t len = strlen (result->pw_name);
char buf[len];
enum nss_status status;
memcpy (buf, &result->pw_name[1], len);
status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
if (status == NSS_STATUS_RETURN)
continue;
if (status == NSS_STATUS_SUCCESS)
{
if (strcmp (buf, result->pw_name) == 0)
return NSS_STATUS_SUCCESS;
}
else if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
return NSS_STATUS_NOTFOUND;
else
return status;
continue;
}
/* +:... */
if (result->pw_name[0] == '+' && result->pw_name[1] == '\0')
{
enum nss_status status;
status = getpwuid_plususer (uid, result, buffer, buflen, errnop);
if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
break;
else if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
return NSS_STATUS_NOTFOUND;
else
return status;
}
}
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_compat_getpwuid_r (uid_t uid, struct passwd *pwd,
char *buffer, size_t buflen, int *errnop)
{
enum nss_status result;
ent_t ent = { false, false, true, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0 },
{ NULL, NULL, 0, 0, NULL, NULL, NULL }};
__libc_lock_lock (lock);
if (ni == NULL)
init_nss_interface ();
__libc_lock_unlock (lock);
result = internal_setpwent (&ent, 0, 0);
if (result == NSS_STATUS_SUCCESS)
result = internal_getpwuid_r (uid, pwd, &ent, buffer, buflen, errnop);
internal_endpwent_noerror (&ent);
return result;
}
/* Support routines for remembering -@netgroup and -user entries.
The names are stored in a single string with `|' as separator. */
static void
blacklist_store_name (const char *name, ent_t *ent)
{
int namelen = strlen (name);
char *tmp;
/* first call, setup cache */
if (ent->blacklist.size == 0)
{
ent->blacklist.size = MAX (BLACKLIST_INITIAL_SIZE, 2 * namelen);
ent->blacklist.data = malloc (ent->blacklist.size);
if (ent->blacklist.data == NULL)
return;
ent->blacklist.data[0] = '|';
ent->blacklist.data[1] = '\0';
ent->blacklist.current = 1;
}
else
{
if (in_blacklist (name, namelen, ent))
return; /* no duplicates */
if (ent->blacklist.current + namelen + 1 >= ent->blacklist.size)
{
ent->blacklist.size += MAX (BLACKLIST_INCREMENT, 2 * namelen);
tmp = realloc (ent->blacklist.data, ent->blacklist.size);
if (tmp == NULL)
{
free (ent->blacklist.data);
ent->blacklist.size = 0;
return;
}
ent->blacklist.data = tmp;
}
}
tmp = stpcpy (ent->blacklist.data + ent->blacklist.current, name);
*tmp++ = '|';
*tmp = '\0';
ent->blacklist.current += namelen + 1;
return;
}
/* Returns whether ent->blacklist contains name. */
static bool
in_blacklist (const char *name, int namelen, ent_t *ent)
{
char buf[namelen + 3];
char *cp;
if (ent->blacklist.data == NULL)
return false;
buf[0] = '|';
cp = stpcpy (&buf[1], name);
*cp++ = '|';
*cp = '\0';
return strstr (ent->blacklist.data, buf) != NULL;
}
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