glibc/nis/nss_compat/compat-spwd.c

907 lines
22 KiB
C

/* Copyright (C) 1996-2016 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
<http://www.gnu.org/licenses/>. */
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <nss.h>
#include <nsswitch.h>
#include <shadow.h>
#include <stdio_ext.h>
#include <string.h>
#include <rpc/types.h>
#include <rpcsvc/ypclnt.h>
#include <libc-lock.h>
#include <kernel-features.h>
#include "netgroup.h"
static service_user *ni;
static enum nss_status (*nss_setspent) (int stayopen);
static enum nss_status (*nss_getspnam_r) (const char *name, struct spwd * sp,
char *buffer, size_t buflen,
int *errnop);
static enum nss_status (*nss_getspent_r) (struct spwd * sp, char *buffer,
size_t buflen, int *errnop);
static enum nss_status (*nss_endspent) (void);
/* Get the declaration of the parser function. */
#define ENTNAME spent
#define STRUCTURE spwd
#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 files;
bool first;
enum nss_status setent_status;
FILE *stream;
struct blacklist_t blacklist;
struct spwd pwd;
struct __netgrent netgrdata;
};
typedef struct ent_t ent_t;
static ent_t ext_ent = { false, true, false, NSS_STATUS_SUCCESS, NULL,
{ NULL, 0, 0},
{ NULL, NULL, 0, 0, 0, 0, 0, 0, 0}};
/* Protect global state against multiple changers. */
__libc_lock_define_initialized (static, lock)
/* Positive if O_CLOEXEC is supported, negative if it is not supported,
zero if it is still undecided. This variable is shared with the
other compat functions. */
#ifdef __ASSUME_O_CLOEXEC
# define __compat_have_cloexec 1
#else
# ifdef O_CLOEXEC
extern int __compat_have_cloexec;
# else
# define __compat_have_cloexec -1
# endif
#endif
/* Prototypes for local functions. */
static void blacklist_store_name (const char *, ent_t *);
static int 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_lookup ("shadow_compat", "passwd_compat",
"nis", &ni) >= 0)
{
nss_setspent = __nss_lookup_function (ni, "setspent");
nss_getspnam_r = __nss_lookup_function (ni, "getspnam_r");
nss_getspent_r = __nss_lookup_function (ni, "getspent_r");
nss_endspent = __nss_lookup_function (ni, "endspent");
}
}
static void
give_spwd_free (struct spwd *pwd)
{
free (pwd->sp_namp);
free (pwd->sp_pwdp);
memset (pwd, '\0', sizeof (struct spwd));
pwd->sp_warn = -1;
pwd->sp_inact = -1;
pwd->sp_expire = -1;
pwd->sp_flag = ~0ul;
}
static int
spwd_need_buflen (struct spwd *pwd)
{
int len = 0;
if (pwd->sp_pwdp != NULL)
len += strlen (pwd->sp_pwdp) + 1;
return len;
}
static void
copy_spwd_changes (struct spwd *dest, struct spwd *src,
char *buffer, size_t buflen)
{
if (src->sp_pwdp != NULL && strlen (src->sp_pwdp))
{
if (buffer == NULL)
dest->sp_pwdp = strdup (src->sp_pwdp);
else if (dest->sp_pwdp &&
strlen (dest->sp_pwdp) >= strlen (src->sp_pwdp))
strcpy (dest->sp_pwdp, src->sp_pwdp);
else
{
dest->sp_pwdp = buffer;
strcpy (dest->sp_pwdp, src->sp_pwdp);
buffer += strlen (dest->sp_pwdp) + 1;
buflen = buflen - (strlen (dest->sp_pwdp) + 1);
}
}
if (src->sp_lstchg != 0)
dest->sp_lstchg = src->sp_lstchg;
if (src->sp_min != 0)
dest->sp_min = src->sp_min;
if (src->sp_max != 0)
dest->sp_max = src->sp_max;
if (src->sp_warn != -1)
dest->sp_warn = src->sp_warn;
if (src->sp_inact != -1)
dest->sp_inact = src->sp_inact;
if (src->sp_expire != -1)
dest->sp_expire = src->sp_expire;
if (src->sp_flag != ~0ul)
dest->sp_flag = src->sp_flag;
}
static enum nss_status
internal_setspent (ent_t *ent, int stayopen, int needent)
{
enum nss_status status = NSS_STATUS_SUCCESS;
ent->first = ent->netgroup = 0;
ent->files = true;
/* 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 = fopen ("/etc/shadow", "rme");
if (ent->stream == NULL)
status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
else
{
/* We have to make sure the file is `closed on exec'. */
int result = 0;
if (__compat_have_cloexec <= 0)
{
int flags;
result = flags = fcntl (fileno_unlocked (ent->stream), F_GETFD,
0);
if (result >= 0)
{
#if defined O_CLOEXEC && !defined __ASSUME_O_CLOEXEC
if (__compat_have_cloexec == 0)
__compat_have_cloexec = (flags & FD_CLOEXEC) ? 1 : -1;
if (__compat_have_cloexec < 0)
#endif
{
flags |= FD_CLOEXEC;
result = fcntl (fileno_unlocked (ent->stream), F_SETFD,
flags);
}
}
}
if (result < 0)
{
/* Something went wrong. Close the stream and return a
failure. */
fclose (ent->stream);
ent->stream = NULL;
status = NSS_STATUS_UNAVAIL;
}
else
/* We take care of locking ourself. */
__fsetlocking (ent->stream, FSETLOCKING_BYCALLER);
}
}
else
rewind (ent->stream);
give_spwd_free (&ent->pwd);
if (needent && status == NSS_STATUS_SUCCESS && nss_setspent)
ent->setent_status = nss_setspent (stayopen);
return status;
}
enum nss_status
_nss_compat_setspent (int stayopen)
{
enum nss_status result;
__libc_lock_lock (lock);
if (ni == NULL)
init_nss_interface ();
result = internal_setspent (&ext_ent, stayopen, 1);
__libc_lock_unlock (lock);
return result;
}
static enum nss_status
internal_endspent (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;
ent->files = true;
if (ent->blacklist.data != NULL)
{
ent->blacklist.current = 1;
ent->blacklist.data[0] = '|';
ent->blacklist.data[1] = '\0';
}
else
ent->blacklist.current = 0;
give_spwd_free (&ent->pwd);
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_compat_endspent (void)
{
enum nss_status result;
__libc_lock_lock (lock);
if (nss_endspent)
nss_endspent ();
result = internal_endspent (&ext_ent);
__libc_lock_unlock (lock);
return result;
}
static enum nss_status
getspent_next_nss_netgr (const char *name, struct spwd *result, ent_t *ent,
char *group, char *buffer, size_t buflen,
int *errnop)
{
char *curdomain = NULL, *host, *user, *domain, *p2;
size_t p2len;
if (!nss_getspnam_r)
return NSS_STATUS_UNAVAIL;
/* If the setpwent call failed, say so. */
if (ent->setent_status != NSS_STATUS_SUCCESS)
return ent->setent_status;
if (ent->first)
{
memset (&ent->netgrdata, 0, sizeof (struct __netgrent));
__internal_setnetgrent (group, &ent->netgrdata);
ent->first = false;
}
while (1)
{
enum nss_status status;
status = __internal_getnetgrent_r (&host, &user, &domain,
&ent->netgrdata, buffer, buflen,
errnop);
if (status != 1)
{
__internal_endnetgrent (&ent->netgrdata);
ent->netgroup = false;
give_spwd_free (&ent->pwd);
return NSS_STATUS_RETURN;
}
if (user == NULL || user[0] == '-')
continue;
if (domain != NULL)
{
if (curdomain == NULL
&& yp_get_default_domain (&curdomain) != YPERR_SUCCESS)
{
__internal_endnetgrent (&ent->netgrdata);
ent->netgroup = false;
give_spwd_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 = spwd_need_buflen (&ent->pwd);
if (p2len > buflen)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
p2 = buffer + (buflen - p2len);
buflen -= p2len;
if (nss_getspnam_r (user, result, buffer, buflen, errnop) !=
NSS_STATUS_SUCCESS)
continue;
if (!in_blacklist (result->sp_namp, strlen (result->sp_namp), ent))
{
/* Store the User in the blacklist for possible the "+" at the
end of /etc/passwd */
blacklist_store_name (result->sp_namp, ent);
copy_spwd_changes (result, &ent->pwd, p2, p2len);
break;
}
}
return NSS_STATUS_SUCCESS;
}
static enum nss_status
getspent_next_nss (struct spwd *result, ent_t *ent,
char *buffer, size_t buflen, int *errnop)
{
enum nss_status status;
char *p2;
size_t p2len;
if (!nss_getspent_r)
return NSS_STATUS_UNAVAIL;
p2len = spwd_need_buflen (&ent->pwd);
if (p2len > buflen)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
p2 = buffer + (buflen - p2len);
buflen -= p2len;
do
{
if ((status = nss_getspent_r (result, buffer, buflen, errnop)) !=
NSS_STATUS_SUCCESS)
return status;
}
while (in_blacklist (result->sp_namp, strlen (result->sp_namp), ent));
copy_spwd_changes (result, &ent->pwd, p2, p2len);
return NSS_STATUS_SUCCESS;
}
/* This function handle the +user entrys in /etc/shadow */
static enum nss_status
getspnam_plususer (const char *name, struct spwd *result, ent_t *ent,
char *buffer, size_t buflen, int *errnop)
{
if (!nss_getspnam_r)
return NSS_STATUS_UNAVAIL;
struct spwd pwd;
memset (&pwd, '\0', sizeof (struct spwd));
pwd.sp_warn = -1;
pwd.sp_inact = -1;
pwd.sp_expire = -1;
pwd.sp_flag = ~0ul;
copy_spwd_changes (&pwd, result, NULL, 0);
size_t plen = spwd_need_buflen (&pwd);
if (plen > buflen)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
char *p = buffer + (buflen - plen);
buflen -= plen;
enum nss_status status = nss_getspnam_r (name, result, buffer, buflen,
errnop);
if (status != NSS_STATUS_SUCCESS)
return status;
if (in_blacklist (result->sp_namp, strlen (result->sp_namp), ent))
return NSS_STATUS_NOTFOUND;
copy_spwd_changes (result, &pwd, p, plen);
give_spwd_free (&pwd);
/* We found the entry. */
return NSS_STATUS_SUCCESS;
}
static enum nss_status
getspent_next_file (struct spwd *result, ent_t *ent,
char *buffer, size_t buflen, int *errnop)
{
struct parser_data *data = (void *) buffer;
while (1)
{
fpos_t pos;
int parse_res = 0;
char *p;
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;
}
/* 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_spent (p, result, data,
buflen, errnop)));
if (__glibc_unlikely (parse_res == -1))
/* The parser ran out of space. */
goto erange_reset;
if (result->sp_namp[0] != '+' && result->sp_namp[0] != '-')
/* This is a real entry. */
break;
/* -@netgroup */
if (result->sp_namp[0] == '-' && result->sp_namp[1] == '@'
&& result->sp_namp[2] != '\0')
{
/* XXX Do not use fixed length buffers. */
char buf2[1024];
char *user, *host, *domain;
struct __netgrent netgrdata;
memset (&netgrdata, 0, sizeof (struct __netgrent));
__internal_setnetgrent (&result->sp_namp[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->sp_namp[0] == '+' && result->sp_namp[1] == '@'
&& result->sp_namp[2] != '\0')
{
int status;
ent->netgroup = true;
ent->first = true;
copy_spwd_changes (&ent->pwd, result, NULL, 0);
status = getspent_next_nss_netgr (NULL, result, ent,
&result->sp_namp[2],
buffer, buflen, errnop);
if (status == NSS_STATUS_RETURN)
continue;
else
return status;
}
/* -user */
if (result->sp_namp[0] == '-' && result->sp_namp[1] != '\0'
&& result->sp_namp[1] != '@')
{
blacklist_store_name (&result->sp_namp[1], ent);
continue;
}
/* +user */
if (result->sp_namp[0] == '+' && result->sp_namp[1] != '\0'
&& result->sp_namp[1] != '@')
{
size_t len = strlen (result->sp_namp);
char buf[len];
enum nss_status status;
/* Store the User in the blacklist for the "+" at the end of
/etc/passwd */
memcpy (buf, &result->sp_namp[1], len);
status = getspnam_plususer (&result->sp_namp[1], result, ent,
buffer, buflen, errnop);
blacklist_store_name (buf, ent);
if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
break;
/* We couldn't parse the entry */
else if (status == NSS_STATUS_RETURN
/* entry doesn't exist */
|| status == NSS_STATUS_NOTFOUND)
continue;
else
{
if (status == NSS_STATUS_TRYAGAIN)
{
fsetpos (ent->stream, &pos);
*errnop = ERANGE;
}
return status;
}
}
/* +:... */
if (result->sp_namp[0] == '+' && result->sp_namp[1] == '\0')
{
ent->files = false;
ent->first = true;
copy_spwd_changes (&ent->pwd, result, NULL, 0);
return getspent_next_nss (result, ent, buffer, buflen, errnop);
}
}
return NSS_STATUS_SUCCESS;
}
static enum nss_status
internal_getspent_r (struct spwd *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 = getspent_next_nss_netgr (NULL, pw, ent, NULL, buffer,
buflen, errnop);
if (status == NSS_STATUS_RETURN)
return getspent_next_file (pw, ent, buffer, buflen, errnop);
else
return status;
}
else if (ent->files)
return getspent_next_file (pw, ent, buffer, buflen, errnop);
else
return getspent_next_nss (pw, ent, buffer, buflen, errnop);
}
enum nss_status
_nss_compat_getspent_r (struct spwd *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_setspent (&ext_ent, 1, 1);
if (result == NSS_STATUS_SUCCESS)
result = internal_getspent_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_getspnam_r (const char *name, struct spwd *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 || buffer[buflen - 1] != '\xff')
{
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_spent (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->sp_namp[0] != '+' && result->sp_namp[0] != '-')
{
if (strcmp (result->sp_namp, name) == 0)
return NSS_STATUS_SUCCESS;
else
continue;
}
/* -@netgroup */
/* If the loaded NSS module does not support this service, add
all users from a +@netgroup entry to the blacklist, too. */
if (result->sp_namp[0] == '-' && result->sp_namp[1] == '@'
&& result->sp_namp[2] != '\0')
{
if (innetgr (&result->sp_namp[2], NULL, name, NULL))
return NSS_STATUS_NOTFOUND;
continue;
}
/* +@netgroup */
if (result->sp_namp[0] == '+' && result->sp_namp[1] == '@'
&& result->sp_namp[2] != '\0')
{
enum nss_status status;
if (innetgr (&result->sp_namp[2], NULL, name, NULL))
{
status = getspnam_plususer (name, result, ent, buffer,
buflen, errnop);
if (status == NSS_STATUS_RETURN)
continue;
return status;
}
continue;
}
/* -user */
if (result->sp_namp[0] == '-' && result->sp_namp[1] != '\0'
&& result->sp_namp[1] != '@')
{
if (strcmp (&result->sp_namp[1], name) == 0)
return NSS_STATUS_NOTFOUND;
else
continue;
}
/* +user */
if (result->sp_namp[0] == '+' && result->sp_namp[1] != '\0'
&& result->sp_namp[1] != '@')
{
if (strcmp (name, &result->sp_namp[1]) == 0)
{
enum nss_status status;
status = getspnam_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->sp_namp[0] == '+' && result->sp_namp[1] == '\0')
{
enum nss_status status;
status = getspnam_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_getspnam_r (const char *name, struct spwd *pwd,
char *buffer, size_t buflen, int *errnop)
{
enum nss_status result;
ent_t ent = { false, true, false, NSS_STATUS_SUCCESS, NULL, { NULL, 0, 0},
{ NULL, NULL, 0, 0, 0, 0, 0, 0, 0}};
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_setspent (&ent, 0, 0);
if (result == NSS_STATUS_SUCCESS)
result = internal_getspnam_r (name, pwd, &ent, buffer, buflen, errnop);
internal_endspent (&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 TRUE if ent->blacklist contains name, else FALSE. */
static bool_t
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;
}